On January 25, 2022, a new study published in JAMA Network, a journal of the American Medical Association, investigated the risk of developing myocarditis in the U.S. population after vaccinating against Pfizer/BioNTech (Pfizer) and Moderna vaccines. The study was conducted by researchers from research institutes and hospitals such as the U.S. Food and Drug Administration (FDA), the U.S. Centers for Disease Control (CDC), Duke University, and Emory University.
The study used data obtained from CDC's VAERS reporting system, which was cross-checked to ensure compliance with cdc's definition of myocarditis.
The researchers note that given the passivity of the VAERS system, the number of reported accidents may be underestimated to the extent to which the phenomenon occurs.
The team studied 1626 cases of myocarditis and found that the Pfizer vaccine was most associated with a higher risk of myocarditis. Men in the 16-17 age group had 105.9 cases per million cases after the second vaccination; men in the 12-15 age group had 70.7 cases per million cases after the second vaccination; and in the 18- to 24-year-old male age group, the incidence of myocarditis with the Pfizer and Moderna vaccines was also significantly higher, at 52.4 and 56.3 cases per million cases, respectively.
The study found that the median time for symptoms to appear was two days, and 82 percent of cases were male, which was consistent with previous studies. About 96% of patients are hospitalized, most patients are treated with NSAIDs, and 87% of inpatients have symptoms disappear by discharge.
Reported symptoms included chest pain, stress, or discomfort (89 percent), shortness of breath (30 percent), abnormal ECG results (72 percent), and cardiac magnetic resonance imaging results (72 percent).
Given the large number of studies confirming the link between vaccination and myocarditis, the CDC has begun to actively monitor adolescents and young adults to monitor their progress in heart-related events after vaccination. However, long-term outcome data are not yet out.
Meanwhile, the American Heart Association and the American College of Cardiology recommend that patients with myocarditis should avoid competitive sports for three to six months and resume strenuous exercise only after obtaining normal ECG and other test results. In addition, they recommend that further mRNA vaccination should be postponed.
Thesis Link:
https://jamanetwork.com/journals/jama/fullarticle/2788346