absolutely wild to see evidence come out that shingles vaccination has a strong link to reduction in alzheimers cases
(via https://mastodon.social/@mhoye/110459991081722237)
the idea that the generation after mine might literally luck into a significant reduction in alzheimers cases due to expanding shingles vaccination and/or the chickenpox vaccine is frankly a little spooky
EDIT: Important caveats brought up by @belarius here https://cohost.org/belarius/post/1591758-here-s-the-crucial-f, notably:
THIS IS A PREPRINT. The manuscript has not completed the peer-review process, and it may transpire that there are methodological or analytic problems that are identified at that stage that invalidate the above conclusions
It's a pretty common minority viewpoint in the research community that herpes viruses cause or contribute to Alzheimer's. Much of the focus is on treating the protein clumps that seem to cause the actual degenerative disease, but why those even happen is an open question.
This is a somewhat confusing graph, so it's important to think it through. The manuscript reports that the September 2 1933 cutoff was the initial cutoff, and that eligibility was then progressively rolled out to younger patients. This created a discontinuity: Those with birthdays earlier than Sept. 2 1933 (left half of the graph) have only a 0.01% chance of receiving the zoster vaccine, whereas those born later than the cutoff (right half of the graph) had a 47.2% chance of receiving the vaccine. In other words, adoption went from zero to roughly one person in two from one side of the cutoff to the other.
This is why the gap in panel A only reports about a 1.3% reduction: It's the average of a mix of vaccine adopters and non-adopters, at roughly a 50-50 split. Put another way, Panel A reports the whole sample, including the unvaccinated folks. Panels B and C then report the estimated difference between adopters and non-adopters, which looks to be in roughly the 3.5% to 4.0% range.
Importantly, the error bars on all of these effects need to be taken seriously, in both directions. The errors bars exclude "zero effect", but only just, so there's a very real chance that the benefits are smaller than those reported here (zero hasn't been definitively ruled out, either; it just looks unlikely based on this sample). By the same logic, the maximum plausible effect of this vaccine, according to this sample, is around a 7% reduction. That's important: This effect can be real and causal without the vaccine acting as a magic bullet.
So, the takeaway here, in my view, is that this points us toward a crucial mechanism of action in Alzheimer's (that is, some consequence of exposure to diseases in the herpesvirus family). Given the effect sizes in question, for example, entirely eradicating Varicella zoster wouldn't reduce Alzheimer's cases to zero.
As a final point worth emphasizing, THIS IS A PREPRINT. The manuscript has not completed the peer-review process, and it may transpire that there are methodological or analytic problems that are identified at that stage that invalidate the above conclusions. Even if it passes peer review, of course, the manuscript may have problems and won't be the final word, but this effect is far from "settled science" and it would be irresponsible to go around saying that this is now a result "that we know." There are still crucial stress tests that science will need to perform.
