Comment by hannob

Did a quick Google search, and it appears that this isn't a new hypothesis, and previous studies had conflicting results.

That seems to be relevant and in direct contradiction: https://www.alzheimersresearchuk.org/no-link-between-shingle... While this is only a correlational result, well, while correlation does not mean causation, you really can't have causation without correlation. So it seems there are conflicting results.

Let's see if this new result holds up. FWIW I'll still certainly get my shingles vaccine once I'm old enough to fall into the recommendation. Shingles is known to be a nasty disease, and making it less likely to get is by itself probably more than enough reason to get the vaccine.