“The entire span of human history has been an arms race of survival adaptations against diseases which seem to be out to completely destroy us, both as individual organisms and as a collective species. Every time we come up with a new technique to combat various communicable diseases, the pathogens responsible change and mutate, becoming better adapted to our weapons against them. Such is the way of all of life.” (Joe Duncan, www.listverse.com). 

As contradictory as it sounds, humans, like all other living species, are in a constant battle with nature for survival...