Influenza vaccination has been shown to significantly reduce cardiovascular risk following infection, particularly in older adults. A recent self-controlled case series study conducted in Denmark from 2014 to 2025 highlights the association between influenza infection and an increased incidence of acute myocardial infarction and stroke, with a sharp rise in hospitalizations occurring within the first week post-infection. The study found that prior vaccination was linked to a marked reduction in this excess cardiovascular risk, with adjusted incidence rate ratios (IRRs) of 4.7 for unvaccinated individuals compared to 2.4 for those who were vaccinated.

These findings underscore the critical role of influenza vaccination in mitigating severe outcomes beyond respiratory illness. The research indicates that influenza infection can provoke acute cardiovascular events through systemic inflammation that destabilizes atherosclerotic plaques and promotes a pro-thrombotic state. The study aligns with previous meta-analyses that estimate a 32% lower risk of cardiovascular events associated with vaccination. Notably, the protective effects were more pronounced among individuals vaccinated early in the influenza season, reinforcing the importance of timely vaccination.

This study shifts the paradigm of influenza vaccination from a purely preventive measure against respiratory disease to a broader strategy for reducing cardiovascular morbidity in older populations. The clear association between vaccination and reduced cardiovascular risk may influence future guidelines and public health policies, emphasizing the need for sustained vaccination efforts in aging populations to enhance healthspan and reduce the burden of cardiovascular events associated with influenza infection.

Source: fightaging.org