Two doses of Pfizer-BioNTech's COVID-19 vaccine was 91 percent effective at preventing multisystem inflammatory syndrome in children, or MIS-C, a rare but serious condition tied to COVID-19, according to the CDC's Jan. 7 Morbidity and Mortality Weekly Report.
While evidence showing high vaccine effectiveness against severe COVID-19 among children and adolescents has been well documented, the shot's effectiveness against MIS-C has been less explored, the report said.
The study involved 283 inpatients aged 12 to 18 across 24 U.S. pediatric hospitals from July to Dec. 9, 2021 — a period in which delta which was the dominant circulating strain and before children younger than 12 were eligible for the vaccine. A total of 102 of the patients had MIS-C, and a control group of 181 patients either tested negative for COVID-19 or did not have symptoms.
Most patients with MIS-C, 95 percent, were unvaccinated, the findings showed. Additionally, no fully vaccinated patient with MIS-C needed respiratory or cardiovascular life support, compared to 39 percent of unvaccinated MIS-C patients who did.
"Receipt of two doses of the Pfizer-BioNTech vaccine is associated with a high level of protection against MIS-C in persons aged 12-18, highlighting the importance of vaccination among all eligible children," researchers said.
Pfizer's vaccine is the only one authorized for use among people under the age of 18. Children 5 and older are eligible for primary vaccination, and boosters are recommended for those 12 and older.