Can evolution make us immune to diseases?
It does and we are continuously becoming immune to specific diseases.
There are lots of examples of certain mutations providing us with some degree of resistance or better survival chances against pathogens or other adverse factors.
For example, humans have developed multiple resistances to malaria through evolution of sickle cell (Sub Saharan Africa), thalassemias (Middle East) and HbE (Asia).
Tuberculosis is also a good example. Between 1600 and 1800 it was one of the main death causes in Europe, particularly in bigger cities, but in the recent years several specific genetic variants of resistance have been identified.
Diseases evolve as well, sometimes becoming less lethal.