Demand for the shingles vaccine has increased in the United Kingdom as some individuals hope it may offer protection against dementia, according to emerging but inconclusive research. The trend reflects growing public interest in preventive measures against dementia, a condition that affects nearly 60 million people worldwide and is expected to rise significantly with global ageing populations.
Shingles, a painful rash caused by reactivation of the varicella zoster virus (which also causes chickenpox), primarily affects older adults when their immune systems weaken. The vaccine, available free on the NHS for some age groups but costing around £450 for those under 65 privately, has traditionally been used to prevent shingles and its complications. However, recent studies have suggested a possible link between shingles vaccination and reduced dementia risk, prompting some to seek immunization for this potential additional benefit.
Researchers at Stanford University examined data from a Welsh shingles vaccination program that started in 2013 offering the live-attenuated vaccine Zostavax. Due to age-based eligibility criteria, the study compared dementia rates between those eligible for the vaccine and those who were not. They found an 8.5% reduction in dementia incidence among women vaccinated with Zostavax over seven years, estimating a nearly 20% risk reduction when accounting for vaccine uptake. Similar findings have been reported in Australia and Canada.
More recently, a team at the University of Oxford investigated the newer shingles vaccine Shingrix by analyzing health records of over 200,000 Americans. Compared with Zostavax recipients, Shingrix recipients experienced a 17% lower incidence of dementia over six years, with women showing a 22% reduction and men 13%. The study’s design, comparing two vaccinated groups, aimed to minimize confounding factors often seen in observational vaccine studies.
Despite these encouraging findings, the evidence is not yet definitive. A 2024 study based on larger English hospital records found no significant protective effect of Zostavax against dementia, raising questions about the vaccine’s efficacy in this regard or differences in data and methodology. The precise mechanism by which shingles vaccination might influence dementia risk remains unclear but could involve reducing brain inflammation associated with viral reactivation or enhancing immune function.
Meanwhile, the vaccine’s established role in preventing shingles is clear, and some individuals say that dementia concerns have influenced their decision to be vaccinated. For example, Jennifer from Cambridge and Sally, a former headteacher from Telford, cited family experiences with dementia as motivating factors for receiving the shingles vaccine. Others like Dominic, an engineer from Dorset, took the vaccine after learning of the potential cognitive benefits alongside the conventional protection against shingles.
Clinical trials underway in Finland and Denmark aim to provide more definitive answers about the vaccine’s potential in dementia prevention, but results are not expected for several years. In the meantime, dementia charities recommend following established brain health practices such as maintaining physical activity, a nutritious diet, and mental engagement rather than relying on the shingles vaccine specifically for dementia prevention.
Researchers involved in the current studies acknowledge the promise of these findings but urge caution until more rigorous evidence is available. The ongoing investigations will help clarify whether shingles vaccination could play a role in reducing the growing burden of dementia globally.