Evidence mounts that shingles vaccines protect against dementia

Recent research indicates that the Shingrix shingles vaccine, introduced in 2017, may be more effective in reducing the risk of dementia compared to the older Zostavax vaccine. A study involving over 200,000 individuals in the US found that those vaccinated with Shingrix were 17 percent less likely to develop dementia within six years compared to those who received Zostavax. Shingles, caused by the reactivation of the varicella-zoster virus, poses a higher risk to older adults, prompting recommendations for vaccination starting at age 50 in the US and 65 in the UK.

The study, led by Maxime Taquet at the University of Oxford, analyzed medical records of individuals vaccinated after the launch of Shingrix and those vaccinated before. While the exact reasons for the reduced dementia risk remain unclear, it is suggested that herpes zoster infections may contribute to dementia, and thus, a more effective vaccine could offer better protection. Notably, women appeared to benefit more from the newer vaccine, despite similar rates of shingles between genders.

Critics of the study point out that it relies on medical records, which may not account for other factors influencing dementia risk, such as lifestyle choices. Additionally, other vaccines, like the BCG vaccine, have also been linked to reduced dementia rates, suggesting that the immune response from various vaccines might play a role in lowering dementia risk.