Risk of myocarditis following SARS-CoV-2 immunisation raised yet very low: Study

According to one research, myocarditis following SARS-CoV-2 immunisation was uncommon but more common in younger guys, especially after the second mRNA-1273 (Moderna) vaccine, showing that vaccine type, age, and gender should all be considered when vaccinating.

The study was published in the Canadian Medical Association Journal (Canadian Medical Association Journal) “In this study, we found higher observed rates of myocarditis after receiving mRNA vaccines than expected, but absolute rates were low,” writes Dr. Naveed Janjua of the University of British Columbia’s School of Population and Public Health and the British Columbia Centre for Disease Control in Vancouver, BC, with coauthors.

Researchers looked at population health data from the BC COVID-19 Cohort, which includes more than 10.2 million doses of mRNA vaccinations given to persons aged 12 and above between December 15, 2020, and March 10, 2022. Almost 7 million doses of BNT162b2 (Pfizer-BioNTech) and 3.2 million doses of mRNA-1273 (Moderna) were administered. The researchers looked for persons who were hospitalised to the hospital or went to the emergency room due to myocarditis between 7 and 21 days after getting the vaccination.

The rate of myocarditis 21 days after vaccination was 1.37 per 100,000 participants, compared to an anticipated rate of 0.39 per 100,000 unvaccinated people. Males (rate: 2.15/100 000), those aged 18-29 (rate: 2.97/100 000), after the second dose (rate: 2.27/100 000 doses), and persons vaccinated with mRNA-1273 (Moderna) (rate: 1.75/100 000) had the greatest risks of myocarditis. The incidence was 22.9/100,000 doses among males aged 18-29 who got the mRNA-1273 (Moderna) vaccination. Myocarditis rates were decreased after the third dosage, especially among those aged 18 to 29.

“The overall rates of myocarditis per 100 000 doses were still very low for both vaccine products,” write the authors. However, they state that their findings “… support the preferential use of the BNT162b2 (Pfizer-BioNTech) vaccine over the mRNA-1273 (Moderna) vaccine for people aged 18-29 years.”

A US study estimated that per million second doses of mRNA SARS-CoV-2 vaccine administered to males aged 12-29 years, 11 000 COVID-19 cases, 560 hospital admissions, 138 ICU admissions, and 6 deaths from COVID-19 could be avoided, compared to 39-47 expected cases of myocarditis after SARS-CoV-2 vaccination.

“The benefits of vaccination against SARS-CoV-2 in reducing the severity of COVID-19, hospital admission and deaths far outweigh the risk of developing myocarditis. … Thus, continued vaccination of this group, along with monitoring of adverse events, including myocarditis, should remain the preferred strategy,” the authors conclude.