Mandatory Vaccinations

Direct exposure is exactly how your immune system builds immunity. So the best way to reduce the problem is to not "fool" the immune system with a vaccine. Vaccines are dead forms of viruses/diseases. However, the immune system only builds a defense against a dead form. If exposed to the living form, the immune system may not be properly prepared for the way the virus/disease acts. Thus causing an infection anyway. Small pox is one example of such occurance, another can be the flu.

Vaccines already are direct exposure. Take the MMR vaccine. It contains "live viruses" that have been chemically inactivated. To your body an antigen is an antigen. It will react the same way to it whether it is a vaccine or the real pathogen.