In the News: Doctors Expected MIS-C Cases to Surge After the Delta Wave. They Didn’t.

Multisystem inflammatory syndrome in children, MIS-C, is a complication of COVID-19 that can lead to dangerous inflammation around several vital organs. It occurs about a month after a SARS-CoV-2 infection and considered relatively rare (CDC has received 5,973 reported cases, with 52 deaths, as of November 30). When the delta variant exploded late summer, doctors braced for a requisite surge of MIS-C cases.

Instead, as reported by NBC News, the rate of MIS-C appears to have dropped. Except, that is, in areas of the country where the delta variant raged and vaccine rates were lower, such as the South. Experts point to several possible explanations: the delta variant coincided with vaccine availability for 12- to 18-year olds, the delta variant itself doesn’t trigger MIS-C to the degree of other variants, or perhaps only an initial exposure to COVID-19 causes MIS-C. [Read More]

And while cases may be down broadly, MIS-C has not gone away. There remain genuine concerns for those children who do develop MIS-C. Those concerns are greater in the South which experienced a “robust and sustained peak” of COVID-19 cases in children, along with a surge in MIS-C cases in the months following the peak.

The identification of the omicron variant reintroduces questions about the incidence of MIS-C cases. Though seen as less severe than delta, the new variant is more contagious. The introduction of vaccines for children as young as five hopefully protects them from the virus and potential MIS-C. Perhaps the wide availability of vaccines will lead to a less virulent virus.

“We held out breath for that four to eight weeks after the [delta] surge, saying, ‘OK, get ready, here comes MIS-C.’ It just never materialized” said PIDS President, Buddy Creech, who is quoted in the article. Also contributing to the story were PIDS members Dr. Roberta DeBiasi (Board of Directors) and Dr. Sean O’Leary (Vice Chair, Vaccine Advocacy Committee).