This reasoning has some justification when we are dealing with a disease like Polio or Smallpox. Does it really justify mandating vaccines for Chicken Pox? If the very low odds of a vaccinated person dying IF the vaccine fails and IF they catch the disease from an unvaccinated person is so low that if you accept it as reasoning to mandate the behavior of others, then you should accept the same reasoning to mandate all sorts of other behavior from regulating why parents can put their child in a car to whether people can own guns or not.
I realize that chicken pox isn't as much of a problem as other diseases but, as others have pointed out, it doesn't always follow a benign course. I think on balance the benefits of vaccination far outweigh the risks.