'they' are all confirmed idiots in this case though: 3/4 got infected instantly, and the last one (MC) almost did. We haven't seen average/smarter people yet so maybe they would be more skeptical of the 1 year.
something like a vaccine would be made in a one year time when the population is rapidly falling for any astute researcher to accomplich such task, they couldn't even identify what killed them except for means of infection.
maybe the researchers' populations aren't falling (or at least at a much lower rate) because they are personally more careful (as intellectuals) and government might quarantine/monitor them more carefully, also may make sure they pass on their research data
consistently in case of emergencies to avoid data loss
If I was in their shoes, with all the virus infecting everyone I would slay them when they start approaching me. I will not see any of them as humans but masquerading one for an easy prey. The virus already turns them into predator so no point seeing them as allies, let alone humans.
pretty dark of you since pushing girls away / running away from girls (read: probably physically weaker than you) shouldn't be too hard.
Also, it might not even be their fault they were infected (like they were raped).
also, the world will really become too chaotic if laws freely allow men to murder in 'self-defense' - especially since if vaccine does get made in a year or two: few to none of the girls dying means remaining men can get a harem and population probably won't decline too much overall.
In all honesty, the virus is made by humans. It's not "I think" but a fact. No such virus targets one specific sex out of its population unless it is engineered by ahem, women who harbor hatred against men.
50/50 really, it's a fictional setting, so don't be too absolute, many sci-fi/virus settings aren't supposed to be realistic, so you do have to turn your brain off to enjoy this sort of thing.