[BorisVSchmid]

Must be for a strange value of "free", when you see http://www.cdc.gov/measles/cases-outbreaks.html

  From January 2 to September 10, 2016, 54 people from 16 states (Alabama, 
  Arizona,California, Colorado, Connecticut, Florida, Georgia, Hawaii, Illinois, 
  Massachusetts, Minnesota, New York, North Carolina, Tennessee, Texas, and Utah) were 
  reported to have measles.

It looks like that with "free" they mean that there is no self-sustainable epidemic possible anymore in the Americas, given the degree of vaccine coverage. Nice.