New studies show that children and teens are developing long COVID at higher rates—especially after multiple infections. Here’s how clinical labs can play a vital role in identifying at-risk patients and supporting early intervention.
As the healthcare system continues to grapple with the lingering effects of COVID-19, new research is drawing attention to a growing—and often overlooked—population: children and teens with long COVID. For clinical laboratory leaders, these findings underscore the continued importance of SARS-CoV-2 testing, variant monitoring, and post-infection diagnostics in younger patients. Studies reviewed by the Center for Infectious Disease Research and Policy (CIDRAP) and others show that long COVID is not only prevalent in youth but more likely to develop after reinfection. With an estimated one million U.S. children already affected, labs play a critical role in helping clinicians identify and manage post-viral complications while providing data that inform vaccine and reinfection risk strategies.
The pooled results of the studies found that long COVID prevalence was 36% among patients who had become infected with the SARS-CoV-2 infection. The highest prevalence was found in South America, and risk factors included being unvaccinated for the virus, contracting a pre-Omicron variant, and being of the female sex.
Another study analyzed from The Journal of Infectious Diseases focused on the effects of long COVID on adolescents in the summer of 2022. In that study, at least one symptom lasted for four weeks or more for 41% of the respondents who also tested positive for a SARS-CoV-2 infection. Adolescents in the study who tested positive also had increased odds of developing neurological symptoms that lasted three months or longer compared to the adolescents in the study who tested negative for SARS-CoV-2. However, the study also concluded that most symptoms are resolved within three months of infection.
Risk Increases with Multiple Infections
The New York Times recently reported that a study published in Lancet Infectious Diseases found that children and teenagers are twice as likely to develop long COVID if they became infected with the virus more than once. The study was a part of the National Institutes of Health’s RECOVER Initiative by examining the records of around 465,000 young people under 21 at 40 United States children’s hospitals.
Over a six-month period, it was found that 1,884 per million young people would develop long COVID after being infected with the virus twice, whereas only 904 per million young people developed long COVID after one infection. The exact numbers of young people with long COVID is not known. However, the Centers for Disease Control and Prevention (CDC) estimates the number stands at about 1 million American children, or 1.3% of the population under 18. A similar trend is seen in adults with long COVID.
These numbers are likely conservative, and the issue of long COVID among youth may be more widespread. According to the same study, tens of thousands of young people in the study were treated for conditions associated with long COVID, such as respiratory symptoms and abdominal pain. Yong Chen, PhD, senior author of the study and professor of Biostatistics at Department of Biostatistics, Epidemiology, and Informatics (DBEI), and a Senior Scholar at Center for Clinical Epidemiology & Biostatistics (CCEB) at the University of Pennsylvania (Penn) Perelman School of Medicine, noted the limitations of the diagnostic code. As quoted by The New York Times, he called the findings a mere “subset of the long COVID.”
Yong Chen, PhD, professor of Biostatistics at DBEI, and a Senior Scholar at CCEB at the University of Pennsylvania (Penn) Perelman School of Medicine said, “Your body really has a memory system and is really going to be hurt from recurrent infection.” (Photo credit: University of Pennsylvania)
Mitigating Risk
Now that we are over five years past the initial worldwide lockdowns, the public has begun to live with significantly less fear–– but the risk remains. “People think that reinfections don’t matter as much and don’t take them seriously,” Chen told Time, “Our primary message is that reinfections still matter, and you should do what you can to avoid reinfection by taking a vaccine or wearing a mask.”
However, the CDC has recently approved recommendations made by Health and Human Services Secretary, Robert F. Kennedy Jr., to remove the blanket recommendation for adults 65 and older to be vaccinated against COVID-19 and recommended that patients between six months and 64 years should discuss with their doctors. Critics of the move warn that these ‘softer’ recommendations may limit insurance coverage of the vaccines.
Clinical laboratory professionals should remain vigilant as research continues to reveal how long COVID affects younger populations. The persistence and variability of post-COVID symptoms highlight the need for continued diagnostic vigilance and testing innovation—not only to confirm infection but to monitor lingering inflammatory, respiratory, or neurological effects. By maintaining awareness of evolving studies and updated guidance from public health agencies, labs can help clinicians identify which patients may be at higher risk for long-term complications. Moreover, laboratory data can support broader efforts to track reinfection patterns, inform vaccine strategies, and guide local health systems in managing the ongoing burden of COVID-related chronic illness.
—Ashley Croce
