The more people refuse to have their kids vaccinated, the more chances of epidemics of these once almost completely done away with/controlled break out, as the above article proves.
The ONLY reason that the aforementioned diseases rarely appeared in America, in the past several decades, is due to parents having their kids vaccinated against having them and nothing else.
Immune systems usually fought off repeats of many diseases only after one had had them!
so you know this as "fact"? What do you base your decisions on?