Close
KTAR.com
News
Shows
Blogs
KTAR News on 92.3FM

For kids with COVID-19, everyday life can be a struggle

Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Stroiney, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Stroiney, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Stroiney, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Stroiney, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Mitchell, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Mitchell, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Mitchell watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Mitchell reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle Mitchell and Rodney Chiles and their daughter, Brooklynn Chiles, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Mitchell in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles looks at her smartphone as her mother, Danielle Chiles, works from home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, lies on an exam room table during a followup visit to Children's National Hospital in Washington, Friday, Feb. 11, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, sits outside exam rooms during a followup visit to Children's National Hospital in Washington, Friday, Feb. 11, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is given a capillaroscopy exam, to look for damage or tiny clots in the small blood vessels in the nailfold, during a followup visit to Children's National Hospital in Washington, Friday, Feb. 11, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles eats popcorn as her mother, Danielle Chiles, left, talks in their home in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Chiles gives her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Lexie Forte, 6, curls up in the plethysmography chamber during a break in her pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Kate Forte kisses her daughter, Lexie Forte, 6, as research nurse Michelle Harris, left, demonstrates a blood draw on her stuffed animal "Sprinkles" at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Lexie Forte, 6, looks to respiratory therapist Tm Murray from inside the plethysmography chamber during a pulmonary function test at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Lexie had COVID-19 and is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Charlie Forte, 8, is prepped for an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. Charlie did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) The animated film Coco is shown on a monitor as Charlie Forte, 8, receives an MRI during a long day of testing at Children's National Hospital, in Washington, Wednesday, Jan. 26, 2022. She picked Coco to watch during the MRI. She did not have COVID-19 but her sister, Lexie, 6, did. Both are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, waits for the elevator with her mother, Tara Carpenter, with stickers and toys given to her during her followup visit to Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 3, at her arm as research nurse Michelle Harris, left, and advanced practice nurse practitioner Lauren Arrigoni, right, draw blood at Children's National Hospital in Washington, Monday, Feb. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter reads the book "Guess How Much I Love You" with her daughter, Alyssa Carpenter, 2, before her afternoon nap in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter holds Alyssa Carpenter, 2, as Hailey Carpenter, 9, plays at her feet and Audrey Carpenter, 5, sits left, as she ties to work in her home office in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. All three girls are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, and her sister Audrey Carpenter, 5, play with toy horses on the floor of the home office of their mother, Tara Carpenter, in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Tara Carpenter carries her daughter, Alyssa Carpenter, 2, and a box of diapers upstairs at their home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, center, sucks on her fingers during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, is helped into tap shoes by her mother, Tara Carpenter,, left, and big sister Audrey Carpenter, 5, right, during Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She and her two sisters are part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, runs around in tap shoes during "Dance Part" at Tiny Tot ballet and tap class at Lyrique Dance in Warrenton, Va., Saturday, Jan. 15, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She had a fever before dance class this morning. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Alyssa Carpenter, 2, looks out of a window of her home in Haymarket, Va., Friday, Jan. 28, 2022. Alyssa has had COVID-19 twice and suffers long-term symptoms. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Chiles talks about her daughter, Brooklynn Chiles, 8, in her bedroom home office in Washington, Wednesday, Feb. 9, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and Brooklynn has tested positive three times. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, holds a tray of her blood samples during a followup visit to Children's National Hospital in Washington, Friday, Feb. 11, 2022. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, is examined during a followup visit at Children's National Hospital in Washington, Friday, Feb. 11, 2022, as her mother, Danielle Chiles watches at right. Brooklynn's father, Rodney Chiles, died of COVID-19 last year and she has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Danielle Chiles reads directions before giving her daughter, Brooklynn Chiles, 8, a COVID-19 antigen rapid test at home in Washington, Sunday, Jan. 9, 2022. Proof of a negative test is required for Brooklynn to attend third grade classes at Rocketship Rise Academy Public Charter School in Washington. (AP Photo/Carolyn Kaster) Family photos of Danielle and Rodney Chiles and their daughter, Brooklynn, decorate the kitchen refrigerator in Washington, Wednesday, Feb. 9, 2022. Rodney died of COVID-19 last year and Brooklyn has tested positive three times. Brooklynn is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster) Brooklynn Chiles, 8, glances up from her smart phone at home where she lives with her mother, Danielle Chiles in Washington, Sunday, Jan. 9, 2022. Brooklynn lost her father to COVID-19 last year and has tested positive three times herself. She is part of a NIH-funded multi-year study at Children's National Hospital to look at impacts of COVID-19 on children's physical health and quality of life. (AP Photo/Carolyn Kaster)