Disease Immunity

[PHLiao]

Diseases like the flu and the cold are rather minor, but are still quite annoying to continue to get multiple times over the course of a round. Even more annoying is the fact that the sterile masks, and even a full biosuit set doesn't grant full immunity to airborne diseases. Thus, I'd like to see if it would be possible to implement some sort of immunity after getting over a disease so that it doesn't come again (and perhaps give diseases like the Cold multiple strains so that it could infect multiple times, but will still die out eventually)