The correlation is probably loosely causative based on other research pointing to certain infections preceding a descent into Alzheimer's or Dementia. Related (not exhaustive. The infectious theory is rapidly gaining ground especially in light of anti-beta-amyloid drugs repeatedly failing in clinical trials): * HSV/Alzheimer's: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8234998/ * HSV/Alzheimer's: https://content.i…
Tdap vaccination is also apparently protective. So, probably too chicken pox vaccination, shingles vaccination, and periodic valacyclovir dosage. Maybe even HPV.
You don't need very good reasons to keep up on your vaccinations.