COVID Paper Database
Myocarditis
COVID-19 Vaccination & Myocarditis
Myocarditis after Covid-19 Vaccination in a Large Health Care Organization
Reviewed by Charles Li, MD
July 19, 2023
Visual Abstract
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Key Points
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Is there a link between COVID-19 vaccination and myocarditis?
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By studying 2.5 million medical records, researchers determined that young men are at the highest risk of developing myocarditis after vaccination.
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Fortunately, most cases of myocarditis in this study were mild. Severe cases were very rare.
Background
Some studies suggest a link between COVID-19 vaccination and myocarditis.
But so far, we don't know enough about how often people get myocarditis after vaccination, and how severe it can get.
This study set out to answer this by looking at 2.5 million medical records in Israel.
Study Quote
Reports have suggested an association between the development of myocarditis and the receipt of messenger RNA (mRNA) vaccines against coronavirus disease 2019 (Covid-19), but the frequency and severity of myocarditis after vaccination have not been extensively explored.
Study Design
Researchers examined medical records from the largest healthcare organization in Israel to determine the rate of myocarditis after COVID-19 vaccination. They performed a retrospective cohort analysis and found 54 cases of myocarditis. There was a small but significant link between these cases and COVID-19 vaccination.
Researchers searched through the records of the largest healthcare organization in Israel for patients who had been diagnosed with myocarditis.
They then collected information on symptoms, severity, and outcomes.
Study Quote
We searched the database of Clalit Health Services, the largest health care organization (HCO) in Israel, for diagnoses of myocarditis in patients who had received at least one dose of the BNT162b2 mRNA vaccine (PfizerāBioNTech)...Among more than 2.5 million vaccinated HCO members who were 16 years of age or older, 54 cases met the criteria for myocarditis.
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Results
Overall, 2.13 out of every 100,000 vaccinated individuals developed myocarditis.Ā
However, this didn't affect everyone equally.Ā Your age and gender can dramatically alter your risk of myocarditis.
Men between age 16 and 29 were around 5x more likely to get myocarditis, with an incidence of 10.69 per 100,000.
Study Quote
The estimated incidence per 100,000 persons who had received at least one dose of vaccine was 2.13 cases (95% confidence interval [CI], 1.56 to 2.70). The highest incidence of myocarditis (10.69 cases per 100,000 persons; 95% CI, 6.93 to 14.46) was reported in male patients between the ages of 16 and 29 years. A total of 76% of cases of myocarditis were described as mild...
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Researchers found that men have a much higher risk of myocarditis after COVID-19 vaccination compared to women. Around 4 men will experience myocarditis for every 100,000 vaccinated, compared to 0.23 women.
Men of all ages were significantly more likely to experience myocarditis than women. Myocarditis after vaccination was exceedingly rare in women, at around 1 case in 400,000 in this study.
Study Quote
The overall estimated incidence of myocarditis within 42 days after the receipt of the first dose per 100,000 vaccinated persons was 2.13 cases (95% confidence interval [CI], 1.56 to 2.70), which included an incidence of 4.12 (95% CI, 2.99 to 5.26) among male patients and 0.23 (95% CI, 0...
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Results: Myocarditis Severity
The risk of myocarditis after COVID-19 vaccination is low, but statistically significant. Fortunately, severe cases are rare. 76% were classified as mild and 22% of cases were classified as intermediate.
Fortunately, most cases of myocarditis were mild. Researchers in this study were able to track how patients did after they got myocarditis.
76% of cases were mild in severity. 22% were intermediate. Only one patient had a severe case.
Conclusions
By analyzing medical records, researchers were able to estimate that the risk of myocarditis was highest in young men between 16-29.Ā
After following cases of myocarditis, researchers determined that most cases were mild. Of the few patients with heart dysfunction, most returned to normal function.
Study Quote
Among patients in a large Israeli health care system who had received at least one dose of the BNT162b2 mRNA vaccine, the estimated incidence of myocarditis was 2.13 cases per 100,000 persons; the highest incidence was among male patients between the ages of 16 and 29 years. Most cases o...
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Researchers examined medical records from a large healthcare organization in Israel to determine the rate of myocarditis after COVID-19 vaccination. They found that risk was highest in men ages 16-29. Most cases found were mild. 22% were intermediate in severity. Fulminant cases were rare.