A large analysis published recently in the journal Pediatrics underscores the toll long COVID can take on children, in some cases leading to neurological, gastrointestinal, cardiovascular and behavioral symptoms in the months after an acute infection.

"Long COVID in the U.S., in adults and in kids, is a serious problem,” said Dr. Ziyad Al-Aly, chief of research and development at the VA St. Louis Health Care System and a clinical public health researcher at Washington University in St. Louis, who studies the condition but was not involved in the new report. He said the paper, which drew on numerous studies of long COVID in children, was "important” and illustrated that the condition can affect multiple organ systems.

The new review suggested that 10% to 20% of children in the United States who had COVID-19 developed long COVID. However, Dr. Suchitra Rao, a pediatric infectious disease expert at Children’s Hospital Colorado and co-author on the paper, said that there are "lots of caveats” with the prevalence estimates used to arrive at that number. For example, some of the studies included looked only at the very small percentage of children who were hospitalized for COVID-19. Like adults, children who had more severe cases of COVID-19 have a greater risk of lingering symptoms or new complications.