Flu Vaccine May Reduce Risk of Heart Attack and Stroke Following Infection
Recent research indicates that influenza vaccination may offer significant protection against cardiovascular complications, including heart attacks and strokes, even for individuals who still contract the flu.
The findings, published in Eurosurveillance by a team of virologists from the European Centre for Disease Prevention and Control (ECDC), suggest that the vaccine could have a substantial impact on public health, particularly for those at high risk of cardiovascular disease. This evidence may help inform new vaccination recommendations across Europe.
Heightened Cardiovascular Risks After Infection
According to the study, catching the flu significantly raises the short-term risk of cardiovascular events. Utilizing Danish health registries with medical data collected between 2014 and 2025, researchers found that the risk of a first-time hospitalization for a heart attack or stroke was markedly higher in the week immediately following a positive PCR flu test.
Specifically, the risk was found to be three times higher for strokes and five times higher for myocardial infarctions compared to any other period before or after the test.
The Protective Role of Vaccination
The research analyzed 1,221 participants aged 40 and older, with a median age of 75. The cohort included 660 men and 561 women. Among the patients hospitalized for cardiovascular events, 65% suffered a stroke, while 35% experienced a myocardial infarction.
Crucially, the researchers observed that this increased risk was reduced by half among individuals who had been vaccinated against the flu. This indicates that the vaccine provides a protective effect against severe cardiovascular complications even when the infection occurs.
The authors did note a specific limitation: the study did not account for differences in efficacy between various flu vaccines, which can vary based on how well the vaccine formulation matches the viral strains circulating during a specific season.
Understanding the Link Between Flu and Heart Health
Medical experts emphasize that influenza is physically demanding on the body. Research from the University of Calgary, led by Dr. Craig Jenne, suggests that the flu can promote vessel inflammation and the formation of blood clots—mechanisms directly associated with heart attacks, and strokes.
Other data from Canada has indicated that the risk of a heart attack can be six times higher in patients with the flu. Long-term studies indicate that flu-related complications, such as pneumonia, can increase the risk of cardiac episodes in the years following an infection, even in individuals with no prior risk factors.
These findings underscore the importance of annual vaccination strategies to mitigate both the respiratory and cardiovascular risks associated with seasonal influenza. For further information on these findings, refer to the analysis of flu vaccine protection against infarction and stroke.
