Lower Risk of Multisystem Inflammatory Syndrome in Children With the Delta and Omicron Variants of Severe Acute Respiratory Syndrome Coronavirus 2

Abstract Little is known about the risk of multisystem inflammatory syndrome in children (MIS-C) with different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. In southeast England, MIS-C rates per confirmed SARS-CoV-2 infections in children aged 0–16 years were 56% lower (rate ratio [RR], 0.34 [95% confidence interval {CI}, .23–.50]) during prevaccine Delta, 66% lower (RR, 0.44 [95% CI, .28–.69]) during postvaccine Delta, and 95% lower (RR, 0.05 [95% CI, .02–.10]) during the Omicron period.