Genetic mutations have never been proven to have a positive effect on people. Take redheads for example. Red hair is a genetic mutation, do they have superpowers? No. Can they do things better than others? No. People who are born with 6 fingers on one hand. That's a genetic mutation. Can they do more things than a person with only 5? No, and usually the extra finger or toe is amputated at birth.
Also, just because a virus builds up an immunity to a drug doesn't prove evolution. It's a good point, but viruses are not classified as living things. It's just like the Tylenol company has to make a stronger pain killer because people's bodies are building up a resistance to the regular kind. I believe it's just the white blood cells just getting stronger and the pill being less effective because the body is getting used to it.