True, most of the time the symptoms are lessened.
Maybe getting mildly sick versus maybe dying.
Case in point: People have stopped immunizing for pertussis in my area. The incidences have increased dramatically over the past year. I wouldn’t want not have been immunized. Whooping Cough was a pretty nasty disease back in the day.
“Prevention by vaccination is of primary importance given the seriousness of the disease in children.”
http://en.wikipedia.org/wiki/Pertussis
The decline of most diseases has been ongoing for a little more than 100 years. With increased access to proper diet, clean water and improved sanitation methods, many diseases were already on the decline when mass vaccination was instituted in the 1950s. If you eat properly, have access to clean water and sanitation and have a healthy immune system, most diseases are easily treatable and survivable in today’s world.