NIH launches research effort to understand MIS-C, other effects of COVID-19 on children

It’s a segment of the population that accounts for roughly 13% of the total cases of COVID-19 in the United States: children. Now, the National Institutes of Health is launching a new research effort to better understand how SARS-CoV-2, the virus that causes COVID-19, affects adolescents, the institute announced Tuesday.

The effort, called the Collaboration to Assess Risk and Identify Long-term Outcomes for Children with COVID (CARING for Children with COVID), develops and funds studies to investigate why some children are at greater risk for SARS-CoV-2 infection than others, why symptoms vary among children who are infected, and how to identify children at risk for severe illness from SARS-CoV-2 infection.

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"This effort stems from NIH’s commitment to understanding the spectrum of risk that SARS-CoV-2 poses for children and to identifying interventions to improve their short- and long-term health outcomes," NICHD Director and CARING for Children with COVID co-chair Dr. Diana Bianchi said.

Research will focus heavily on cases of MIS-C, a rare inflammatory syndrome in children linked to COVID-19.

According to the U.S. Centers for Disease Control and Prevention, MIS-C is a condition in which different body parts can become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs.

Symptoms of MIS-C include fever, abdominal pain, vomiting, diarrhea, neck pain, rash, bloodshot eyes, and feeling tired.

"Based on current data, most children with SARS-CoV-2 infection do not develop serious illness. However, those who do go on to develop MIS-C can experience prolonged fever and severe abdominal pain and may progress to shock," the NIH wrote.

RELATED: MIS-C: Cases of rare inflammatory syndrome linked to COVID-19 on the rise among children in US

While most children with MIS-C survive, its long-term effects — including fatigue, muscle pain, joint paint and respiratory problems — remain largely unknown.

"While much of the devastation wrought by COVID-19 is on older and vulnerable populations, it is affecting children in ways we are just beginning to understand," said Dr. Gary Gibbons, director of the NHLBI and co-chair of CARING for Children with COVID. "That’s why this research and these networks are so critical."

In August, the CDC reported that nearly 600 children had been hospitalized in the United States with multisystem inflammatory syndrome in children, or MIS-C.

Most cases have been identified in children and adolescents between the ages of 1 and 14 years, while 69% of reported cases have occurred in children who are Hispanic or Latino, according to the health agency.

Since CDC reporting on MIS-C began in mid-May, 48 states, New York City, and Washington, D.C. have reported at least one case of MIS-C to the CDC. Most of those jurisdictions have had 11 or more reported cases.

Over that time, there have been more than 2,000 cases of MIS-C reported in the United States and 30 deaths, according to the latest data from the CDC as of Feb. 8.

Dr. Jean Ballweg, medical director of pediatric heart transplant and advanced heart failure at Children’s Hospital & Medical Center in Omaha, Nebraska, told the New York Times that the hospital was only treating about two cases of MIS-C cases per month from April through October last year.

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Ballweg said the number of monthly cases rose to 10 in December and January with 60% requiring intensive care.

The CDC said that the inflammatory condition was first reported in the United Kingdom as early as late April. On May 12 last year, New York City Mayor Bill de Blasio said 100 children in the city had been diagnosed with MIS-C. Of the 100, 55 tested positive for COVID-19 or had antibodies indicating a previous infection.

Medical experts had initially thought the syndrome could be linked to Kawasaki disease, another rare childhood condition that can cause swelling and heart problems, because the symptoms of the two conditions are similar.

More than a year into the pandemic, researchers are still stumped by an array of ever-evolving symptoms and long-term effects that appear in coronavirus patients.

The Associated Press and Austin Williams contributed to this story.