Patients are seven times more likely to develop myocarditis after a COVID-19 infection than after receiving a COVID-19 vaccine, according to a new meta-analysis published in Frontiers in Cardiovascular Medicine.[1] Myocarditis has been one of the most commonly discussed side effects associated with both COVID-19 and the vaccines designed to combat it.
The study’s authors explored data from nearly 58 million patients, including 55.5 million patients who were vaccinated against COVID-19. The median age was 49 years old, and 51% of patients were women. The median follow-up time after COVID-19 infection or COVID-19 vaccination was 28 days. Patients included in the study received a vaccine developed by Pfizer, Moderna, Novavax, AstraZeneca or Johnson and Johnson.
While 1.07% of patients with myocarditis were hospitalized, 0.015% died. Sixty-one percent of patients who developed myocarditis—either after being vaccinated or after a COVID-19 infection—were men. A meta-regression analysis confirmed that men faced a higher risk of developing myocarditis. Also, the team noted, higher rates of myocarditis were seen in United States and Mexico than other parts of the world.
The relative risk of developing myocarditis was 15 among COVID-19 patients. Among patients who had been vaccinated, however, the relative risk was two.
“Our findings show that the risk of myocarditis from being infected by COVID-19 is far greater than from getting the vaccine,” co-author Navya Voleti, DO, a resident physician in the department of medicine at Penn State Health Milton S. Hershey Medical Center in Hershey, Pennsylvania, said in a prepared statement. “Moving forward, it will be important to monitor the potential long-term effects in those who develop myocarditis.”
“COVID-19 infection and the related vaccines both pose a risk for myocarditis. However, the relative risk of heart inflammation induced by COVID-19 infection is substantially greater than the risk posed by the vaccines,” added lead author Paddy Ssentongo, MD, PhD, also a resident physician in the department of medicine at Milton S. Hershey Medical. “We hope our findings will help mitigate vaccine hesitancy and increase vaccine uptake.”
In August, another large study—this one covering 43 million patients—resulted in a similar conclusion.
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.