Make virus carriers a thing
Created by: Hoshi-chan
As in, being immune to a virus personally, but continuing to carry it and be infectious to others. Maybe it could be a genetics power, provided to traitor virologists via TCs?
I dunno, I've always wanted to be the plaguebringer as an antag, but you're either infected with 20 diseases and their progress is stunted by spaceacillin, or you're immune and awkwardly trying to infect people indirectly, through monkeys, tainted chem pills, and broken dishes.