Multisystem Inflammatory Syndrome in Children Among Persons Who Completed a Two-dose COVID-19 Vaccine Primary Series Compared With Those Reporting No COVID-19 Vaccination, US National MIS-C Surveillance

We analyzed multisystem inflammatory syndrome in children cases by reported COVID-19 vaccination status (2-dose primary series vs. no vaccination). A total of 46% vaccinated versus 58% unvaccinated persons received intensive care unit-level care (P = 0.02); the risk of intensive care unit admission was 23% higher (adjusted relative risk: 1.23; 95% confidence interval: 1.03-1.48) among unvaccinated patients; 21 unvaccinated persons died. Multisystem inflammatory syndrome in children occurs after SARS-CoV-2 infection in vaccinated persons, but may be less severe.