Overview
- An analysis of more than 100 million U.S. health records found people with multiple shingles episodes had a 7–9% higher dementia risk three to nine years after a second outbreak.
- Within three years of vaccination against shingles, dementia incidence was 27–33% lower in eligible adults in the same large U.S. dataset.
- A Welsh vaccination campaign used as a natural experiment was associated with about 20% fewer dementia cases, plus 3 percentage points fewer diagnoses of mild cognitive impairment and roughly 30% lower dementia-related mortality over nine years.
- Scientists propose potential mechanisms such as direct viral effects on the brain or immune-driven damage, while noting that the newer Shingrix vaccine’s specific impact on dementia has not been established.
- Public-health guidance continues to recommend shingles vaccination for older adults, yet uptake remains low in parts of Germany, with only 22.6% of Barmer-insured people over 60 in Rhineland-Palatinate fully vaccinated in 2023.