A matched US study of 72,920 adults aged 60 and older linked the recombinant shingles vaccine to a 9% lower composite burden of ischemic heart disease, heart failure or ischemic stroke over seven years.
The analysis used a natural experiment around the 2017-2018 switch from live to recombinant shingles shots, comparing 36,460 people vaccinated in each period to reduce healthy-vaccinee bias.
The association was strongest for ischemic heart disease and heart failure, with 10% and 12% lower burden respectively; ischemic stroke fell 12% in men, and atrial fibrillation dropped 7%.
The benefit appeared mainly in the first 3.5 years and then weakened, while checks against COVID timing, secular trends and negative-control outcomes supported the finding.
Researchers said the observational results do not prove causation but are strong enough to justify clinical trials and mechanistic studies of possible cardioprotective effects.