New Study Sheds Light On Heart Health Post-COVID Vaccine

Starting in April 2021, health officials began receiving reports related to cases of myocarditis and pericarditis emerging following COVID-19 mRNA vaccination (via MedicalNewsToday). Usually, both are the result of a viral infection. Myocarditis is characterized by heart muscle inflammation, while pericarditis pertains to inflammation of the tissue around the heart. Both conditions are considered to be exceptionally rare.

In an analysis of nearly 50 studies, new research published in the British Medical Journal (BMJ) lends further evidence to support the rarity of myocarditis and pericarditis following vaccination. Researchers reviewed data from more than 10,000 participants that included personal patient accounts, published literature, primary studies, health records, and more. The study team was able to break down the research to identify potential risk levels as they pertain to age, sex, and vaccine brand. Health experts ultimately determined that the risk for myocarditis and pericarditis is greater following COVID-19 infection than after receiving the vaccine. After viral infection, symptoms of either condition may involve chest pain and shortness of breath, according to VCU Health.

How vaccine dosing changes could impact heart inflammation risks

Overall, the study determined that the risk of developing myocarditis following vaccination was low, measuring at 0.2 per 1 million people (per MedicalNewsToday). The risk of pericarditis stood at 1.4 per 1 million people, but the team did see an increased risk for myocarditis amongst young adult males. Adolescent males between the ages of 12 and 17 had prevalence rates of 50 to 139 cases per million, while 28 to 147 cases per million were observed in adult males ages 18 through 29, as outlined in the research.

Researchers also discovered the risk for myocarditis to be somewhat higher in Moderna recipients than in those who received the Pfizer vaccine (via BMJ). Based on these findings, the study team suggests leaving more than 30 days between the first and second dose of an mRNA vaccine to help significantly mitigate the risk of myocarditis and pericarditis. Specifically, researchers suggested spacing doses at least 56 days apart for the young adult male demographic. However, more research is still needed to support this theory, particularly as research into young child cases was limited.