The list of things they work working on is too long for a headline. I personally find HIV the least interesting (since I'm at extremely low risk by lifestyle - I'd still get the vaccine it work works, but it isn't a big deal to me). To me the correct headline is "moderna isn't working on vaccines for any of the cancers my family members are currently fighting" I have no doubt that someone else will read the article and respond "you idiot, they work working on X which is the most important things possible" - X of course being different for each personal situation.

HIV has effective prevention through both condom use and pre-exposure prophylactic treatment. The vaccine is a big deal in reducing costs, but, it's not as big a deal as the flu vaccine (or even as big as HPV was).

Bunch of reasons. The biggest (IMO) is that HIV is an STD. The next is that it is associated with the gay community.

Those two factors mean that it is nearly guaranteed to upset a bunch of religious nutjobs.