I am praying to god you are not a doctor!!!

First of all evelution cant happen to an indervitual, it's a population of inderviduals that slowly evolves due to mutations in there genctic make up.

And as for your other point, when you get a desease you immune system kicks in and your memory cells grip onto the pathogen and copy the protine sequence on the suface of it and make antibodies to combat it, even when the desease is gone your body still has those antibodies in it so if the desease comes back they attack and destroy it right away and u dont feel a thing.
Now lungs work nothing like that at all, they dont have a memory and so cant develop a tolorance.