Shingles vaccine and decrease risk for dementia?

Interesting summary of some recent studies that have shown decreased incident of dementia / alzheimer's disease in patients who got the shingles vaccine:

https://www.wsj.com/health/wellness/shingles-vaccine-appears-to-lower-dementia-risk-6acdcc23?st=vv1vDV&reflink=article_gmail_share

I am not totally sure what to make of this but what is most interesting to me is that more than one study has shown this now.