There are two distinct classes of vaccinations: those for communicable diseases like measles, rubella, and chicken pox, and those for non-communicable ones like tetanus.

There is no reason to be vaccinated against non-communicable diseases if you don’t want to. If you believe that your small chance of getting tetanus isn’t worth the (very, very) much smaller risk of crippling Guillan-Barre syndrome after the vaccination, that’s your business.

But vaccination for communicable diseases is part of a social contract that maintains civil society with a general ethic that no one has the right to harm someone without serious provocation. The fact that someone else may avoid vaccination gives no license to avoidably infect that person, however foolhardy he or she might be.