Myocarditis risk higher after COVID-19 infection than after vaccination, new study of 43 million patients confirms
Patients face a much higher risk of myocarditis after a COVID-19 infection than after receiving a COVID-19 vaccine, according to new research published in Circulation.[1] Several research teams have already reached the same conclusion, but this latest analysis is one of the largest to date to examine the issue.
The study’s authors focused on data from 42.8 million people 13 years old or older who received at least one dose of a COVID-19 vaccine. Participants received either the ChAdOx1 vaccine, the Pfizer-BioNTech COVID-19 vaccine or the Moderna COVID-19 vaccine. All vaccinations occurred in England from December 2020 to December 2021.
Overall, 2,861 patients—0.007% of the total cohort—were hospitalized or died from myocarditis over the course of the study. A total of 617 of those myocarditis cases occurred within 28 days of a COVID-19 vaccination, and 514 of those cases resulted in a hospitalization.
Key takeaways from the group’s findings included:
- Unvaccinated COVID-19 patients are 11 times more likely to develop myocarditis as a result of their infection, compared to the COVID vaccine.
- The risk of COVID-related myocarditis appeared to be half as much among patients who had been received at least one dose of a vaccine prior to infection.
- While COVID-19 vaccines are associated with a small increase in the risk of myocarditis, the risk of COVID-related myocarditis remained higher in all instances except after the second dose of the Moderna vaccine.
- Women under the age of 40 faced a “slightly increased” risk of myocarditis after receiving a second dose of the Moderna vaccine.
- Men under the age of 40 faced an increased risk of myocarditis after a first dose of the Pfizer-BioNTech or Moderna COVID-19 vaccines, or a second dose of any of the three COVID-19 vaccines.
“It is important for the public to understand that myocarditis is rare, and the risk of developing myocarditis after a COVID-19 vaccine is also rare,” co-author Nicholas Mills, PhD, cardiology chair at the University of Edinburgh, said in a prepared statement. “This risk should be balanced against the benefits of the COVID-19 vaccines in preventing severe COVID-19 infection.”
“These findings are valuable to help inform recommendations on the type of COVID-19 vaccines available for younger people and may also help shape public health policy and strategy for COVID-19 vaccine boosters,” added co-author Julia Hippisley-Cox, MBChB, MD, with the University of Oxford. “The SARS-CoV-2 virus continues to shift, and more contagious variants arise; our hope is that this data may enable a more well-informed discussion on the risk of vaccine-associated myocarditis when considered in contrast to the net benefits of COVID-19 vaccination.”
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.