People who receive the shingles vaccine may have a lower risk of developing dementia, and this reduction in risk appears to be greater for women than for men.

We analyzed the available evidence and found that 59 studies or assertions suggest the shingles vaccine may be linked to a lower risk of dementia, with the reduction appearing stronger in women than in men [1]. This does not mean the vaccine prevents dementia, but rather that among those who received it, women showed a larger drop in dementia rates compared to men in the data reviewed. We did not find any studies that contradicted this pattern. The evidence we’ve reviewed so far leans toward a difference in how the vaccine might relate to dementia risk between genders, but we cannot say why. It’s possible biological, hormonal, or lifestyle factors play a role, or that differences in vaccine uptake, healthcare access, or how dementia is tracked in men versus women influenced the results. We also don’t know if the vaccine itself is directly responsible, or if other factors common among women who get vaccinated are contributing. Because all 59 assertions point in the same direction without any refuting data, this pattern is consistent — but it’s still early. The studies we’ve seen are observational, meaning they track patterns over time rather than test cause and effect. We don’t have randomized trials that prove the vaccine changes dementia risk differently by gender. What we’ve found so far suggests it’s worth paying attention to gender differences in how vaccines might affect long-term brain health — but more research is needed to understand what’s really happening. If you’re considering the shingles vaccine, talk to your doctor. For now, the best reason to get it remains preventing shingles and its complications — the possible link to dementia is still being studied.