Vaccination policy by country: orange -- Mandatory vaccination blue -- Voluntary vaccination green -- Vaccination not mandatory, but proof of vaccination needed to enroll in public schools
There's been some discussion this year in the news, because of the increase in measles cases this year, about public health regulations and their relation to vaccination rates. Many countries do not require vaccination, but still have good vaccination rates. There is some tension between parental autonomy and the public health of the population, one that is solved for the most part when parents are sufficiently rational about their children's health.
Map from Wikipedia,