Can you tell me how have humans evolved to develop strategies (systems,etc.) that protect against infectious disease?

Highly sophisticated: Thankfully the way God made us -we have immune systems that operate on multiple levels. We can trace back these systems to the earliest life forms -fever, in itself, is one of the most primitive defenses. Just by 'turning up the heat' it makes it harder for germs to survive within us. Then there are systems in the blood (complement), specialized cells - B cells/T cells, specialized organs. Amazing