The mRNA COVID-19 vaccines were considered safe and effective by regulatory agencies, and indeed their wide use, which started in early 2021, possibly saved millions of lives and was able to keep the pandemic under control. However, several groups of patients, including some physicians, identified myocarditis and pericarditis as potential adverse events caused by the vaccine, and in some cases, events were fatal for patients.  The FDA sponsored a large observational clinical trial to shed more light on this debate, recently published in the Lancet entitled: “Risk of myocarditis and pericarditis after the COVID-19 mRNA vaccination in the USA: a cohort study in claims databases”.1

“Several passive surveillance systems reported increased risks of myocarditis or pericarditis, or both, after COVID-19 mRNA vaccination, especially in young men. We used active surveillance from large health-care databases to quantify and enable the direct comparison of the risk of myocarditis or pericarditis, or both, after mRNA-1273 (Moderna) and BNT162b2 (Pfizer–BioNTech) vaccinations.”1

The study was very large, perhaps one of the largest observational trials ever performed.  “A total of 411 myocarditis or pericarditis, or both, events were observed among 15 148 369 people aged 18–64 years who received 16 912 716 doses of BNT162b2 and 10 631 554 doses of mRNA-1273. Among men aged 18–25 years, the pooled incidence rate was highest after the second dose, at 1·71 (95% CI 1·31 to 2·23) per 100 000 person-days for BNT162b2 and 2·17 (1·55 to 3·04) per 100 000 person-days for mRNA-1273. The pooled IRR in the head-to-head comparison of the two mRNA vaccines was 1·43 (95% CI 0·88 to 2·34), with an excess risk of 27·80 per million doses in mRNA-1273 recipients compared with BNT162b2.”1

According to the authors, “An increased risk of myocarditis or pericarditis was observed after COVID-19 mRNA vaccination and was highest in men aged 18–25 years after a second dose of the vaccine. However, the incidence was rare. Our study results, along with the benefit-risk profile, continue to support vaccination using either of the two mRNA vaccines.”1

Read the full article here.

Disclaimers

  • The material in these reviews is from various public open access sources, meant for educational and informational purposes only
  • Any personal opinions expressed are those of only the author(s) and are not intended to represent the position of any organization(s)
  • No official support by any organization(s) has been provided or should be inferred

References

  1. Wong, H. L., Hu, M., Zhou, C. K., Lloyd, P. C., Amend, K. L., Beachler, D. C., Secora, A., McMahill-Walraven, C. N., Lu, Y., Wu, Y., Ogilvie, R. P., Reich, C., Djibo, D. A., Wan, Z., Seeger, J. D., Akhtar, S., Jiao, Y., Chillarige, Y., Do, R., . . . Anderson, S. A. (2022). Risk of myocarditis and pericarditis after the COVID-19 mRNA vaccination in the USA: a cohort study in claims databases. The Lancet, 399(10342), 2191–2199. https://doi.org/10.1016/s0140-6736(22)00791-7