Our Hong Kong partners have published a case-control study that confirms a low but increased relative risk of carditis associated with receipt of a Pfizer mRNA BNT162b2 COVID-19 vaccination.
Researchers from the University of Hong Kong used a territory-wide public health care database to identify patients aged 12 years or older who were hospitalised with carditis. Each case was compared with 10 control participants selected from all other hospitalised patients and randomly matched on age, sex, and admission date. The incidence of carditis following receipt of Pfizer mRNA vaccine, CoronaVac inactivated vaccine or no vaccination were compared.
Consistent with outcomes observed in earlier studies from around the globe, multivariable analyses showed that the odds of developing carditis were higher in mRNA vaccine recipients compared with no vaccination. Of the mRNA vaccine recipients, the odds of carditis were higher in adolescents compared with adults, males compared with females, and after the second dose compared with the first.
The full paper Carditis after COVID-19 vaccination with a messenger RNA vaccine and an inactivated virus vaccine is available on the Annals of Internal Medicine website.