Can the herpes zoster vaccination be a strategy against dementia?

Herpes Zoster (HZ), caused by the reactivation of the varicella-zoster virus (VZV), is a common infectious disease. Recent studies suggest a potential association between HZ and the development of dementia, particularly Alzheimer's disease and other neurodegenerative disorders. Epidemiological evidence indicates that HZ infection, especially in individuals with central nervous system involvement, may increase the risk of dementia. Pathologically, VZV may contribute to neuronal dysfunction and degeneration by inducing chronic neuroinflammation, infection-related cerebrovascular lesions, and direct central nervous system toxicity. HZ vaccines, particularly novel recombinant subunit vaccines (e.g., Shingrix), not only effectively prevent HZ but may also confer cognitive protection through mechanisms such as "trained immunity" activation and anti-inflammatory response modulation. Multiple natural experiments and retrospective cohort studies have found that HZ vaccination is significantly associated with a reduced risk of dementia, with particularly pronounced protective effects in women and older adults. Although most evidence currently stems from observational studies and is subject to potential confounding factors, the biological plausibility and consistent findings support the potential of HZ vaccination as an adjunctive strategy for dementia prevention. Future prospective randomized controlled trials are needed to further clarify the causal relationship and underlying neuroimmune mechanisms, providing a stronger evidence base for establishing scientific vaccination strategies for older adults and dementia prevention systems.