Rare MIS-C Does Not Appear to Impact COVID-19 Vaccine Safety in Children

Children and adolescents with multisystem inflammatory syndrome (MIS-C) did not report serious complications after receiving a COVID-19 vaccination, according to researchers from the National Institutes of Health who recently published a study in JAMA Network Open.

Although nearly 50% of patients experienced arm soreness and fatigue after receiving the COVID-19 vaccine, none reported serious reactions, including myocarditis or MIS-C reoccurrence.

“We are very reassured by the results and this safety data should be comforting to families and healthcare professionals when considering and recommending vaccination,” study co-leader Matthew D. Elias, MD, pediatric cardiologist at Children’s Hospital of Philadelphia, clinical assistant professor of pediatrics at the University of Pennsylvania, Philadelphia said in a press release.

The Centers for Disease Control and Prevention (CDC) said that approximately 1 in 3000 to 4000 children and adolescents who contracted COVID-19 got the potentially fatal MIS-C, developing symptoms including stomach pain, fever, rash, or myocarditis (inflamed heart muscle) within a few weeks of COVID-19 infection. There are not enough data to suggest that COVID-19 vaccination can lead to serious complications in children with a history of MIS-C.

The researchers conducted a cross-sectional study to examine its long-term effects. The Long-Term Outcomes After the Multisystem Inflammatory Syndrome in Children (MUSIC) trial studied 385 racially diverse children and adolescents who were previously diagnosed with MIS-C and are now eligible for COVID-19 vaccination.

Among 48.1% of adolescents who receive 1 COVID-19 dose, 49% experienced mild adverse events like the general population, including arm soreness and fatigue. No child experienced myocarditis or recurrent MIS-C symptoms.

Some experts suggest that the study supports the CDC recommendation for adolescents and children with a history of MIS-C to be vaccinated at least 90 days following inflection. The evidence further suggests that MIS-C patients can be safely vaccinated.

Data show that cases of childhood MIS-C are decreasing, which may be attributed to increasing COVID vaccinations that are “protective against this rare condition in those who have received it,” said study co-leader Audrey Dionne, MD, a pediatric cardiologist at Boston Children’s Hospital and assistant professor of pediatrics at Harvard Medical School, Boston, in a statement.

More than 9000 children and adolescents have been diagnosed with MIS-C. Although most have a full clinical recovery, 74 children have died, and others still experience chronic symptoms. The researchers said they are proponents of long-term studies.

“In light of the acute and long-term consequences of COVID-19 it is vital to continue the development, testing, and deployment of preventive as well as therapeutic agents in at-risk groups as well as the general population,” said Gary H. Gibbons, MD, director of the National Heart, Lung, and Blood Institute, in the press release.

Reference

NIH/National Heart, Lung and Blood Institute. COVID-19 vaccine for children after MIS-C appears safe. EurekAlert. News Release. January 3, 2022. Accessed on January 4, 2022. https://www.eurekalert.org/news-releases/975414