A LARGE matched cohort study presented at IDWeek 2025 has found that prior zoster vaccination significantly reduces the risk of serious long-term complications following herpes zoster (shingles) infection in older adults. The findings suggest that the benefits of zoster vaccination extend beyond preventing shingles itself, lowering risks of cardiovascular events, dementia, and all-cause mortality.
The retrospective analysis used the TriNetX Analytics Network to assess health outcomes in 38,092 adults aged 50 and older who developed a first-time herpes zoster infection. Participants were divided equally into vaccinated and unvaccinated groups, matched for age, comorbidities, and other relevant factors. The median follow-up period was approximately 3.7 years.
Zoster Vaccine and Cardiovascular Protection
Individuals with prior zoster vaccination, whether with recombinant (RZV) or live-attenuated (ZVL) formulations, had a markedly lower risk of major adverse cardiovascular events (MACE), including myocardial infarction, stroke, pulmonary embolism, and sudden cardiac death. Vaccinated adults showed a hazard ratio (HR) of 0.787 (95% CI: 0.750–0.827; p<0.0001), indicating a roughly 21% reduction in cardiovascular risk compared with unvaccinated counterparts.
All-cause mortality was also significantly lower among the vaccinated group (HR: 0.586; 95% CI: 0.530–0.647; p<0.0001), suggesting that zoster vaccination may mitigate systemic inflammation triggered by shingles reactivation, a known factor contributing to vascular and neurologic events.
Zoster Vaccine and Reduced Dementia Risk
Beyond cardiovascular outcomes, the study demonstrated that prior zoster vaccination was associated with a reduced risk of developing dementia after herpes zoster infection (HR: 0.839; 95% CI: 0.772–0.913; p<0.0001). However, vaccination did not significantly alter risks for psychiatric disorders or Parkinsonism, with hazard ratios close to 1.0.
Researchers noted that these findings support a potential neuroprotective role of zoster vaccination in older adults, possibly mediated through reduced systemic inflammation and vascular injury following viral reactivation.
Together, the results reinforce the broader health benefits of zoster vaccination and highlight its importance as part of comprehensive preventive care for ageing populations.
Reference
Dehghani A et al. Impact of Prior Zoster Vaccination on Cardiovascular, Dementia, and Mortality Outcomes Following Herpes Zoster Infection: A Matched Cohort Study. Abstract 218. IDWeek 2025, 19-22 October, 2025.
