Background: HSV1 is commonly known as cold sores. Some people get them in their mouth, or on their lips. Most of the population don't develop any symptoms.
This link between HSV1 and Alzheimer's could be big business. The numbers are wildly divergent, but it sounds like a sizable chunk of the US population has HSV1. I've seen estimates from 20% to 80%. Even if it's the very conservative 20% number, that's still a big market.
The skeptic in me (his name is David) is suspicious of this article precisely because it has the potential to be such a big market. Case in point, there's a link to some HSV1 medicine at the bottom of the article. I wonder if they have an affiliate marketing arrangement with the makers of acyclovir. Tangentially related, I think that this article is on the front page of HN precisely because HSV1 is so widespread. For example, if another article discussed a cure for Alzheimer's, but that article involved some rare condition that does not affect the general population, would that article hit page #1?
With that said, I think our society's lax approach to HSV1 is bizarre. In Sex Ed, I didn't get any education around the fact that kissing people and sharing drinks can spread a virus. After reading quite a few articles on the virus, I got the impression that STD researchers don't really know much about it. I could be wildly incorrect about that last point, I'm not a medical expert. It's just the general impression I got when trying to understand HSV1 from an STD perspective. For example, it's been common wisdom for a long time that, if you have HSV1 (cold sores), then you can't get HSV2 (genital herpes). But the reality seems to be more ambiguous than that. Apparently there was a fairly recent study mentioning that college students who have HSV1 performed oral sex on their partners and transferred HSV1 to the partner's genitals. Or something like that.
Long story short, although I'm skeptical of the business incentives around associating HSV1 with something as scary as Alzheimer's, I welcome more research around understanding HSV1.