COVID-19 Vaccination and Heart Health:
A groundbreaking study of 45.7 million adults in England, published in Nature Communications in 2024, challenges one of the most persistent myths about COVID-19 vaccines—that they harm the heart. Using linked health records from December 2020 to January 2022, researchers tracked the occurrence of arterial thromboses, including heart attacks and strokes, before and after vaccination.

The findings were striking: after the first dose, the risk of these cardiovascular events dropped by about 10%, with even stronger protection after additional doses. Recipients of the Pfizer–BioNTech vaccine experienced a 20% lower risk, while those who received AstraZeneca’s ChAdOx1 saw a 27% reduction.
The study also confirmed that rare side effects—such as myocarditis linked to mRNA vaccines and clotting disorders tied to adenoviral vaccines—do occur, but they are uncommon and typically arise within weeks of vaccination. Crucially, the data showed that COVID-19 infection poses a far greater threat to cardiovascular health, dramatically increasing the risk of heart attacks, strokes, and other complications.
While this was an observational study and cannot prove causation beyond doubt, its sheer scale, robust statistical adjustments, and alignment with other research make its message clear: COVID-19 vaccines, on balance, protect heart health rather than harm it.
summary :
A massive study of 45.7 million people in England found that COVID-19 vaccination is linked to lower rates of heart attacks and strokes—about 10% lower after the first dose, and up to 20–27% lower with Pfizer or AstraZeneca. Rare side effects like myocarditis and clotting can occur but are uncommon. COVID-19 infection itself poses a far greater heart risk, and overall, the evidence suggests vaccines protect heart health rather than harm it.