CHOP-led Study Shows COVID-19 Vaccine Appears Safe for Children with a History of MIS-C

COVID-19 vaccination appears to be safe for children with a history of multisystem inflammatory syndrome in children (MIS-C), according to a multicenter study co-led by researchers at Children’s Hospital of Philadelphia (CHOP). The study, published today in JAMA Network Open, found that patients with a history of MIS-C who received a vaccine at least 90 days after diagnosis reported no serious complications, with no incidence of myocarditis or recurrent MIS-C.

“We are very reassured by the results,” said Matthew Elias, MD, an attending cardiologist in the Cardiac Center at Children's Hospital of Philadelphia and first author of the study. “This safety data should be comforting to families and healthcare professionals when considering and recommending vaccination.”

MIS-C is a rare, severe inflammatory response that occurs a few weeks after SARS-CoV-2 infection. Although studies have shown that COVID-19 vaccines decrease the risk of severe COVID-19 infection and complications, there is little data on the safety of vaccination after MIS-C. The Centers for Disease Control and Prevention (CDC) recommends delaying COVID-19 vaccination until at least 90 days after MIS-C diagnosis, but until now, it was unclear whether these patients were at risk of another hyperinflammatory response after vaccination.

To answer this question, the investigators reached out to vaccine-eligible patients enrolled in the NIH–sponsored multicenter study, Long-Term Outcomes After the Multisystem Inflammatory Syndrome in Children (MUSIC). Participants answered questions about their COVID-19 vaccination status and adverse reactions. To be included in the study, patients needed to be at least 5 years old and at least 90 days from a MIS-C diagnosis.

Of 385 vaccine-eligible patients who were surveyed, 185 (48.1%) received at least one vaccine dose. Among this group, patient-reported adverse reactions were mild, the most common being arm soreness (33.5%) and fatigue (17.3%), similar to the general population. There were no diagnoses of myocarditis or recurrent MIS-C, and none of the patients who had reactions needed medical testing or hospitalization.

Learn more about this study here. More information about the MUSIC study can be found here.