Study: Updated Covid-19 vaccine significantly reduces the risk of heart attack and stroke

The updated Covid-19 vaccine not only helps protect against infection, but is also associated with a significant reduction in the risk of heart attack, stroke, and other serious cardiovascular complications, according to a new study.

The research, published in the scientific journal JAMA Internal Medicine, concluded that vaccinated individuals were about 38% less likely to experience serious cardiovascular events linked to Covid-19 infection.

As part of the study, scientists examined data from nearly 1 million elderly Americans during 2024–2025. They compared two groups: those who had received only the seasonal flu vaccine and those who had been vaccinated against both the flu and Covid-19.

After an average follow-up period of eight months, it was found that in the group vaccinated against Covid, the risk of heart attack, stroke, or other serious heart complications after infection with the virus was 37.7% lower.

The protective effect was especially noticeable among people over the age of 75, as well as those with underlying conditions, including diabetes, cardiovascular disease, and chronic lung problems. According to the authors, the vaccine also appears to provide protection for individuals who may have had a Covid-19 infection without realizing it.

The study also highlighted that vaccinated people had approximately a 6% lower risk of serious heart disease overall, even in cases not directly linked to Covid-19. At the same time, there was also a roughly 7% reduction in hospitalizations and deaths from all causes.

According to the researchers’ calculations, for every 10,000 vaccinated people, an average of 23 major cardiovascular events, 30 hospitalizations, and 16 deaths could be prevented.

However, the authors emphasize that these findings should be read with caution, since the study was conducted mainly among elderly Americans, the majority of whom were men.

Experts also note that Covid-19 vaccines have been associated in very rare cases with myocarditis and pericarditis, but these complications are usually mild. According to them, the benefits of vaccination remain clearly greater than the possible risks.