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CDC study: Pfizer's Covid vaccine is 91% effective in preventing rare condition in adolescents age 12-18
From CNN’s Deidre McPhillips
Teens receive their vaccination cards after being vaccinated in Los Angeles in May 2021. (Patrick T. Fallon/AFP/Getty Images)
The Pfizer/BioNTech Covid-19 vaccine is 91% effective in preventing multisystem inflammatory syndrome (MIS-C) in adolescents age 12 to 18, according to a study published Friday by the US Centers for Disease Control and Prevention.
MIS-C is a rare but serious condition that involves the inflammation of various organs and generally occurs two to six weeks after infection with Covid-19.
The CDC study found that the vast majority — 95% — of adolescents hospitalized with MIS-C were unvaccinated, and all that required respiratory or cardiovascular life support were unvaccinated.
“This analysis lends supportive evidence that vaccination of children and adolescents is highly protective against MIS-C and COVID-19 and underscores the importance of vaccination of all eligible children,” the researchers wrote.
For this study, CDC researchers analyzed data for 283 adolescents ages 12 to 18 who were hospitalized between July and December 2021, a period during which the Delta variant was dominant. The cohort included 102 patients with MIS-C and 181 control patients. Children under 12 were not included in this analysis, as they were not yet authorized to receive a Covid-19 vaccine during the time that the study was conducted. The median age of patients included in the study was 14.5 years and more than half had at least one underlying medical condition.
There have been more than 6,400 cases of MIS-C reported to the CDC, including 55 deaths.
About 54% of adolescents ages 12 to 17 are fully vaccinated, and 16% of children ages 5 to 11 are fully vaccinated against Covid-19, according to the latest data from the CDC.
This specific study does not assess the effectiveness of the Pfizer vaccine against MIS-C attributed to the Omicron variant. Also, the researchers note that the timing in which protection against MIS-C is conferred is unknown. The study does not evaluate protection after one dose of vaccine or the potential effects of waning immunity or protection.
