How much say should a person have in what they do with their body when it has consequences for other people's health?

We should all be able to choose how we take care of (or neglect) our bodies. But what about times when our choices could affect the health of other people? On a small scale choices a mother makes during a pregnancy can affect the health of her child, sometimes severely. On a large scale anti-vaccers were the probable cause of a recent pertussis epidemic in California by compromising herd immunity. That’s whooping cough. Several people died, most, if not all of them, infants that were simply too young to get their injections.

So where should the line be drawn?