Updated COVID-19 vaccine cuts heart events in veterans

A new study has found that the updated COVID-19 vaccine continues to provide significant protection against serious cardiovascular complications, particularly for older adults and individuals with underlying health conditions. The research, published Monday in JAMA Internal Medicine, analyzed data from over one million patients in the Veterans Affairs health system.

The study focused on patients who received a seasonal flu shot between September and December of 2024. Of the 1,039,659 individuals tracked, approximately 349,000 also received the 2024-2025 COVID-19 vaccine at the same time, while the remaining 690,000 received only the flu vaccine and served as a control group. After eight months of follow-up, researchers compared the incidence of major adverse cardiovascular events (MACE)-including cardiovascular death, heart attack, stroke, and hospitalization for heart failure-between the two groups.

Overall, the COVID-19 vaccine was 38 percent effective at preventing COVID-associated MACE. In absolute terms, this translated to a reduction from about 5 events to 3 events per 10,000 people. The protective effect was strongest for patients aged 75 and older, with a vaccine...