My comments in brackets.
- Herpes zoster vaccination reduced dementia diagnosis in our prior natural experiments. [Previous work. I’m familiar with the Wales experiment where they had a sharp age cutoff for getting the vaccine in their national health system. Comparing those just below and just beyond the cutoff allows for analysis similar to a randomized controlled trial (aka ‘natural experiment’). The results showed a ~20% decrease in dementia due to vaccine, so the results were already pretty strong.]
- Here, we find a lower occurrence of MCI and dementia deaths among dementia patients [MCI = ‘mild cognitive impairment’. This is a more refined result than prior work, harder to see in the data than a clear dementia diagnosis.]
- Herpes zoster vaccination appears to act along the entire clinical course of dementia. [This is not surprising given the earlier results, but the demonstration is harder, and it may lead to recommendations for earlier HZ vaccination, IIRC currently at 50 or 55 in the US.]
- This study’s approach avoids the common confounding concerns of observational data [Basically they are improving their methods and getting stronger results, classic good science.]