Overview
- An analysis reported in Cell finds vaccinated adults were less likely to develop mild cognitive impairment and had nearly a 30% lower risk of dementia-related death over nine years.
- Earlier work using Welsh health records showed about a 20% lower likelihood of a dementia diagnosis over seven years among people who received the shingles vaccine.
- A separate 2024 Nature Medicine study reported a 17% drop in dementia diagnoses for at least six years after vaccination, reinforcing the association.
- The evidence remains observational, with a quasi-experimental design exploiting a strict UK age cutoff for eligibility, which improves inference but does not prove causality.
- Most data involve the discontinued Zostavax vaccine, leaving uncertain whether the currently recommended Shingrix confers similar benefits, and researchers have yet to secure funding for randomized trials.