Shingles, also known as herpes zoster, is a viral disease that causes a painful rash as well as pain and general malaise. There is a vaccine called Shingrix that’s recommended for people older than 50. There are now several studies that link receiving the shingles vaccine to reduced risk for dementia (Eyting et al. 2025 and its follow-up by Xie et al. 2025; Tang et al. 2025; Taquet et al. 2025). None of them is a placebo-controlled clinical trial, which would deliver definitive proof of causality. But because the studies arrive at similar results while taking different approaches and using different data, it’s likely that Shingrix does in fact protect against dementia, including Alzheimer’s. The study by Eyting et al. suggests the effect size isn’t small either: Being eligible for Shingrix reduces the risk for dementia by 20% compared to those who just missed the eligibility cutoff. Since not everyone who’s eligible took the vaccine, the real effect may be even higher.
I have a hard time processing this. Contrast this quite unexpected discovery to the billions the biopharmaceutical industry has invested into finding something to protect against or cure Alzheimer’s over decades, with basically nothing to show for it.
Nehaveigur 