Flu vaccination linked to 40% reduced risk of Alzheimer’s disease

It's quite remarkable that an effect of this size on such a large group seems to have gone undetected for such a long time. As a layman, I would almost have expected geriatricians to have made the observation during their own practice.

Also quite remarkable that the flu vaccine seems to have a larger impact on the prevalence of Alzheimer's disease than it does on, well, influenza.

The same 40% effect size was seen for Tdap vaccination.

Although, Tdap and flu vaccination are pretty strongly correlated.

It was noticed, thus prompting these studies.