Annals of Internal MedicineDementia Risk After Recombinant Herpes Zoster Vaccination in Older Adults with a Recent Skilled-Nursing Facility Stay

ℹ️ Observational Association Only Evidence

Prior observational studies suggested dementia protection from herpes zoster vaccination, but relied on the live attenuated vaccine no longer available in the US. This target trial emulation using Medicare claims linked to SNF EHR data examines RZV specifically, following 509,926 adults aged 66 and older for up to 4 years across a 2017–2022 admission window.

Clinical Considerations

• RZV receipt was associated with 24% lower relative dementia risk (RR 0.76; CI, 0.69–0.84) and a 5.8 percentage point absolute risk reduction over 4 years
• Only 1.73% of eligible participants received RZV within 12 months of SNF admission, representing a substantial vaccination gap in a high-risk population
• Protective association was attenuated in men and in those with prior live HZ vaccination history
• Negative control analyses flagged residual confounding; GSK funding warrants acknowledgment when contextualizing findings

Practice Applications

• Recognize SNF admission and post-discharge follow-up as an actionable vaccination opportunity for RZV in eligible older adults
• Consider prior live HZ vaccination status when counseling patients, as protective association appears attenuated in this group
• Interpret dementia risk reduction as hypothesis-generating; do not frame RZV as a dementia prevention strategy in patient conversations
• Monitor for randomized trial data that could confirm or refute this association before adjusting dementia counseling protocols