RECOVER researchers develop new tools to help identify Long COVID in youngest children
A recent RECOVER study found that infants (aged 0 to 2) were likely to experience different Long COVID symptoms than preschool-aged children (aged 3 to 5).
Long COVID affects people of all ages and can look different for everyone. While most Long COVID research has focused on understanding Long COVID symptoms in adults, fewer studies have explored what Long COVID looks like in children. In order to better understand how to diagnose, prevent, and treat Long COVID across the lifespan, RECOVER studies include adults (both pregnant and non-pregnant), children, and adolescents.
In August 2024, RECOVER researchers published a study on Long COVID symptoms in children and adolescents between the ages of 6 and 17. However, studying Long COVID in earlier childhood can be challenging. Young children experience rapid developmental changes as they grow and often can’t describe how they feel. Parents and caregivers must notice and report any symptoms, making their role essential in understanding how Long COVID affects this age group.
In a new publication featured in the Journal of the American Medical Association (JAMA) Pediatrics, RECOVER researchers continued their study of Long COVID symptoms in children, examining how Long COVID may affect children 5 years old or younger—and how Long COVID symptoms in early childhood differ from those seen in older children and adults. This study, which represents the first large multisite study to explore Long COVID symptoms seen in early childhood, resulted in researchers developing 2 tools to recognize the condition in the youngest children.
What did researchers do?
Researchers analyzed data from 1,011 children aged 5 or younger who are part of RECOVER’s pediatric observational study. As part of the observational study, parents or caregivers completed surveys to report on their children’s health. Researchers compared the symptoms of children who had a SARS-CoV-2 infection, the virus that causes COVID-19, with the symptoms of children who did not. In this study, Long COVID symptoms had the following characteristics:
- The symptoms lasted more than 4 weeks.
- The symptoms began or worsened after the start of the COVID-19 pandemic.
- The symptoms were still present when parents completed the survey.
What did researchers find?
The study found that Long COVID symptoms differed between infants and toddlers (ages 0 to 2) and preschoolers (ages 3 to 5).
Among infants and toddlers, the most common symptoms were:
- Trouble sleeping.
- Fussiness.
- Poor appetite.
- Stuffy nose.
- Dry or wet cough.
Among preschool-aged children, the most common symptoms were:
- Dry cough.
- Daytime tiredness.
- Sleepiness or low energy.
This finding is similar to results from last year’s RECOVER study examining Long COVID symptoms in children ages 6 to 17, which found that specific age groups experienced different symptoms. These age-based differences in symptoms may reflect how Long COVID is observed and reported in young children. Symptoms like fatigue, brain fog (difficulty thinking or concentrating), or pain might be difficult to detect when a child can’t describe them, while symptoms such as cough or disrupted sleep are easier for parents and caregivers to observe.
Why is this research important?
The unique symptoms of Long COVID in early childhood underscore the need for age-specific approaches to diagnosing, preventing, and treating Long COVID. Expanding our knowledge of how Long COVID may appear in early childhood can help families and healthcare providers better recognize the condition and support children who are experiencing Long COVID symptoms.
As part of their 2024 study focusing on children and adolescents, RECOVER researchers developed a tool called a research index that can be used by researchers to identify which children and adolescents are most likely to have Long COVID based on their symptoms. Because last year’s study only included children ages 6 to 17, the use of this research index was limited to a specific age range. The 2025 study took a similar approach, with researchers developing 2 research indexes to help identify Long COVID in young children: a research index specific to infants and toddlers, and a research index specific to preschool-aged children.
Researchers using the research indexes to identify Long COVID in children aged 0 to 5 should keep in mind that children identified as likely to have Long COVID may also experience symptoms not included in the tool. Although the tools are designed for research and not for clinical or diagnostic purposes, researchers can use the tools in future studies that examine risk factors for Long COVID or symptom patterns in early childhood.
To learn more about the study and its findings, read the full publication in JAMA Pediatrics. Find additional information about pediatric Long COVID authored by RECOVER researchers and a RECOVER Representative on JAMA Pediatrics’ Patient Page.
