Flu Vaccine Even with Infection Reduces Risk of Heart and Stroke
- By BSTQ Staff
A new study shows that influenza vaccination may help protect against heart attack and stroke even when it does not prevent people from getting the flu.
In the study, researchers at the Statens Serum Institut in Copenhagen analyzed data from a Danish health registry from the 2015-16 to 2023-24 flu seasons to identify adults aged 40 years and older who experienced a first-time hospitalization for acute myocardial infarction (AMI) or stroke within a year of laboratory-confirmed flu infection. Of the 1,221 identified adults, 610 were vaccinated, and 621 were not.
They found that AMI risk increased roughly five-fold, and stroke risk rose about three-fold in the first week after flu infection compared with other time periods. But flu vaccination appeared to significantly reduce that risk. In fact, findings showed the risk of heart attack or stroke was reduced by half in participants who had received a flu vaccine compared with unvaccinated participants.
References
Croci1, R, Young, JJ, Emborg, H-D, et al. Influenza Vaccination Attenuates Acute Myocardial Infarction and Stroke Risk Following Influenza Infection: A Register-Based, Self-Controlled Case Series Study, Denmark, 2014 to 2025. Eurosurveillance, Volume 31, Issue 13, 02/Apr/2026. Accessed at www.eurosurveillance.org/content/10.2807/1560-7917.ES.2026.31.13.2500706.