Overview
- A Cell report from a Stanford-led team finds herpes zoster vaccination is associated with slower disease course in people already diagnosed with dementia, including fewer severe symptoms and a lower likelihood of dying from dementia over long-term follow-up.
- The same research group previously reported about a 20% lower risk of receiving a dementia diagnosis in the seven years after vaccination.
- The analyses leveraged a 2013 Welsh policy that offered the shingles shot only to people who were 79 on a specific date, creating near-randomized groups across more than 280,000 health records.
- Similar associations were observed in datasets from England, Australia, New Zealand and Canada, with effects appearing stronger among women.
- Investigators caution these are observational findings and are pursuing mechanistic studies and randomized trials to test causality and explain potential roles for viral reactivation, neuroinflammation or immune modulation.