Shingles vaccine lowers dementia risk, new study finds

Key Points:

• A study published in Annals of Internal Medicine found that elderly nursing home residents who received at least one dose of the Shingrix shingles vaccine had a 24% lower risk of developing dementia over four years compared to unvaccinated residents.
• The research analyzed health records of over 500,000 nursing home residents aged 66 and older, using methods designed to mimic randomized clinical trials, highlighting a vulnerable population often excluded from such studies.
• Previous large-scale studies have also linked shingles vaccination, including Shingrix and the older Zostavax vaccine, to a reduced risk of dementia, with vaccinated individuals showing 18-33% lower dementia risk over several years.
• Experts caution that while the association between shingles vaccination and reduced dementia risk is promising, it does not establish causation, and more research is needed before recommending the vaccine specifically for dementia prevention.
• Theories for the protective effect include prevention of shingles-related brain inflammation or vascular damage caused by the varicella-zoster virus, with ongoing research by vaccine maker GlaxoSmithKline to better understand these mechanisms.