[hn_throwaway_99]

Do you have a link to these studies? I ask because, as another commenter mentioned, I think it would be very difficult to tease out cause and effect and I think the "healthy vaccinee" hypothesis could easily explain why so often you see the association between any vaccine (just here we have shingles, influenza and pneumococcal) and Alzheimer's risk reduction.

To be clear, I would get those vaccines regardless for their stated effectiveness, it just feels like so many observational conclusions ("moderate red wine is good for you!") have been proven to be non-causitive correlations when examined more closely.

Edit: Actually, the youtube link posted above talks about tons of vaccines where observational studies show reduced Alzheimer's risk: https://youtu.be/qlTnnQytOJ0?t=340

[gdudeman]

I believe that there are studies that show that merely getting very sick increases your chance of dementia - essentially it ages you faster or brings chronic disease forward. If that's the case, vaccines for things like the flu - a disease you're likely to get - are probably good overall.

They also activate the immune system in generaly, which could probably go either way in terms of longevity.

In general I don't think vaccines are preventing so much as delaying dementia, but if they stop chronic infection they might be.

[emceestork]

https://www.neurology.org/doi/10.1212/WNL.0000000000214782

edit: Sorry this is the follow up study but the 40% study is linked within