NEJM Journal Watch
Paul S. Mueller, MD, MPH, FACP, reviewing
These results counter evidence from adverse-events reports and trial data.
Some adverse-event reports and trial data suggest immunization with an mRNA COVID-19 vaccine is associated with developing appendicitis. In this study, Danish researchers used national registry data to identify all recipients of either the Pfizer-BioNTech or Moderna vaccines and all adolescents and adults (age, ≥12) with PCR-confirmed SARS-CoV-2 infections between December 2020 and November 2021; the comparison group comprised all unvaccinated people who were tested for SARS-CoV-2 infections.
Among ≈4 million people who were immunized with mRNA vaccines, incidence of acute appendicitis within 21 days of either a first or second dose was about 8 episodes per 100,000 vaccinated people. Compared with the unvaccinated reference group, no excess risk for appendicitis was observed. These results were similar by age, sex, and vaccine type. Notably, risk for appendicitis among individuals with PCR-confirmed SARS-CoV-2 infection was not higher than the risk for the unvaccinated reference group.
COMMENT
In this large study, immunization with an mRNA COVID-19 vaccine was not associated with developing appendicitis. Despite the study’s retrospective design, these results should be reassuring to clinicians and recipients of mRNA vaccines.
CITATIONS
Kildegaard H et al. Risk of appendicitis after mRNA COVID-19 vaccination in a Danish population. JAMA Intern Med 2022 Apr 25