Levy M, Recher M, Hubert H, et al. - Findings indicate that COVID-19 mRNA vaccination was related to a lower incidence of MIS-C (multisystem inflammatory syndrome in children; a severe complication linked with SARS-CoV-2) among adolescents.

• In France, a fourth wave of COVID-19 cases emerged in summer 2021 along with a recommendation to vaccinate children 12 years and older, and this report estimates the risk of MIS-C in adolescents by COVID-19 vaccination status during September 2021 and October 2021.

• Vaccination was not received by the majority of the adolescents with MIS-C for whom vaccination was indicated in France.

• The median time between single vaccine injection and MIS-C onset was 25 days vs a mean 28-day delay between SARS-CoV-2 infection and MIS-C onset.

• This indicates that in most cases, SARS-CoV-2 infection developed prior to or shortly after the vaccine injection, when immune response was incomplete.

• In fully vaccinated children, MIS-C cases were absent, which averted estimation of a hazard ratio for this group, but indicates that 2 doses are warranted for efficient protection.

• Assessing the relationship between mRNA vaccination with MIS-C in younger children is advised as vaccines are approved for use in children aged 5 to 11 years.

• Given the alert on myocarditis developing in adolescents post-COVID-19 mRNA vaccine, a close monitoring is needed.