WEDNESDAY, March 2, 2022 (HealthDay News) -- Multisystem inflammatory syndrome in children (MIS-C) is rare after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, especially for those without evidence of SARS-CoV-2 infection, according to a study published online Feb. 22 in The Lancet Child & Adolescent Health.
Anna R. Yousaf, M.D., from the U.S. Centers for Disease Control and Prevention COVID-19 Response Team, and colleagues examined potential cases of MIS-C in individuals aged 12 to 20 years after COVID-19 vaccination. Demographic and clinical features of cases were described, stratified by laboratory evidence of SARS-CoV-2 infection. The reporting rate of MIS-C was calculated.
The researchers identified 21 individuals with MIS-C after COVID-19 vaccination using surveillance results from Dec. 14, 2020, to Aug. 31, 2021. All 21 were hospitalized and subsequently discharged home; 57 percent were admitted to the intensive care unit. Of the 21 individuals, 15 (71 percent) and six (29 percent) had and did not have, respectively, laboratory evidence of past or recent SARS-CoV-2 infection. As of Aug. 31, 2021, 21,335,331 individuals aged 12 to 20 years had received one or more COVID-19 vaccine doses. Consequently, the overall reporting rate for MIS-C was 1.0 case per million individuals receiving one or more doses in this age group. Among those without evidence of SARS-CoV-2 infection, the reporting rate was 0.3 cases per million vaccinated individuals.
"Our results suggest that MIS-C cases following COVID-19 vaccination are rare and that the likelihood of developing MIS-C is much greater in children who are unvaccinated and get COVID-19," Yousaf said in a statement.
Several authors disclosed financial ties to the biopharmaceutical and health information technology industries.