RECOVER to launch next phase of pediatric observational study
As children in the study grow and develop, researchers will investigate how Long COVID continues to impact them through new surveys, in-person assessments, and collection of biosamples.
In early 2027, RECOVER will launch the next phase of its pediatric observational cohort study, expanding the study for 2 additional years and continuing to follow more than 4,300 children, teens, and young adults who took part in the first phase.
This next phase builds on one of the first phase’s most important findings: not only does Long COVID look different in children than it does in adults, but it also looks different among age groups across childhood and adolescence. Continuing the study will allow researchers to understand what happens as children grow and transition into new age groups. Do their Long COVID symptoms change to mimic the patterns initially seen by researchers among different age groups, or do their symptoms remain consistent with those they experienced at younger ages?
During the first phase of the pediatric observational study, more than 15,000 participants and more than 7,800 caregivers helped RECOVER learn about the various ways Long COVID can impact children and young people of different ages, as well as their families. Participants in the study completed more than 23,000 surveys, attended over 8,400 office visits, and took part in nearly 94,000 tests.
“The RECOVER pediatric study is one of the largest in the world to comprehensively follow and characterize Long COVID in children across the full pediatric lifespan, from infancy through young adulthood,” said Rachel Gross, MD, MS, principal investigator at the RECOVER Clinical Science Core at NYU Grossman School of Medicine.
The second phase will follow an estimated 4,374 participants. This group includes 2,875 children and young adults who were previously selected in the first phase to be followed over time for several years completed the entire first phase of the pediatric study, as well as 1,499 young children from the pregnancy study, many of whom were exposed to COVID-19 during pregnancy.
During the second phase, researchers will collect data from participants through remote surveys, in-person assessments, and biosamples. Study participants will continue to contribute data and biosamples through March 2029. Data analysis and reporting of study findings will continue through September 2029.
To prepare for the 2027 launch of the next phase, researchers are currently consulting working groups, submitting study designs, receiving consent from participants, and building and launching surveys.
What researchers hope to learn
Researchers designed this next phase to continue to follow study participants as they move into a new stage of life—from infant to toddler, from toddler to preschooler, from school age into adolescence, and from the teenage years into young adulthood. Researchers estimate that during both phases of the pediatric observational study, about 92% of participants will go through at least one transition into the next age group. Being able to follow children for up to 6 years gives RECOVER researchers an unprecedented window into how Long COVID may evolve as a child develops.
“We know that children are not just little adults and they are developing and changing over time,” said Dr. Gross. “We want to understand why we see these age differences over time. We also want to understand the underlying mechanisms, the biology leading to Long COVID, so that we can identify targets for prevention and treatment. It’s possible that these targets or underlying mechanisms may be different across ages or developmental stages.”
This phase will help researchers continue to understand how Long COVID can affect the bodies of young people, including the brain and other organs, as well as how long the effects of Long COVID may last, whether symptoms get better or worse, and how the condition may change as children get older. Researchers will also continue following the children from the pregnancy study to see being exposed to COVID-19 during pregnancy affects their health and development over time.
New phase will include new survey questions and lab tests
Working groups that include researchers, subject matter experts, and RECOVER Patient, Caregiver, and Community Representatives spent recent months refining what the study will focus on and how it will address these questions.
In addition to continuing to collect data on the many symptoms that can occur with Long COVID, new survey questions will take a deeper look at fatigue, pain, sleep, gastrointestinal symptoms (related to the stomach and digestive system), coughing, and eating habits. When possible, the study will use assessments that are already validated for children.
In response to needs researchers heard from study participants during the first phase, they added additional survey questions focused on school-related outcomes, including grades and activities, accommodations such as Individualized Education Programs (IEPs) and 504 plans, and the stigma some children feel because of their health.
An in-depth interview process will also capture the medications and non-pharmaceutical treatments participants receive to better understand the relationship between Long COVID treatments and symptoms. Collecting this information could help to inform the direction of future pediatric clinical trials.
Biosample collection will continue during this next phase of the study. All pediatric participants will be asked to contribute blood twice during the study, and they will also contribute stool (poop), urine (pee), hair samples, and skin, nasal, and oral swabs once during the study.
New lab tests will look at hormone levels to help track differences that may emerge around puberty, along with markers of inflammation in the gastrointestinal (digestive) system and the brain. These are 2 mechanisms that researchers believe may explain some of the most common Long COVID symptoms in children.
Smell and taste tests will also be included in the next phase of the study. Changes in smell and taste are a known Long COVID symptom among adolescents, young adults, and adults, but researchers don’t yet know how common this is in younger children, who often can’t verbally describe these changes. Collecting objective data about children’s smell and taste can help researchers to understand whether these symptoms may be linked to other symptoms such as poor appetite, a common symptom among younger children with Long COVID.
The impact of the next phase
The pediatric observational study represents the full lifespan of young people, across the United States. Combined across its first and second phases, the study will span 6 years of data collection—making it one of the largest and most diverse pediatric Long COVID studies in the world. This positions RECOVER to continue making important discoveries about pediatric Long COVID. Findings may include information about the mechanisms underlying this condition in young people, as well as how the condition affects them as they move through childhood, adolescence, and young adulthood.
“The pediatric study was designed to be foundational for mechanistic [or pathobiology] studies, ancillary studies, and to inform clinical trials—both clinical trials that will come from RECOVER-TLC, as well as other clinical trials [outside of RECOVER],” said Dr. Gross. As an example, she shared that the first phase of the pediatric study is informing the Brave-LC (low-dose naltrexone) trial led by RECOVER-TLC, shaping question design, outcome evaluation, and potential biomarkers for future exploration.
On September 15, RECOVER will host an R3 Seminar on the pediatric observational study. Researchers—including Dr. Gross—will share the latest findings on how Long COVID affects children's daily lives, explore factors that may influence a child's risk of developing Long COVID, and preview what's ahead in the study's next phase. Register to attend and hear directly from the researchers leading the pediatric observational study.
