On the other side are those who believe that the science is far from settled, and believe that parents should have the right to choose what gets injected into their children's bodies without fear of punishment.

The latest skirmish of this battle was on Monday in Trenton, NJ, where a bill proposing one of the nation's broadest bans on religious exemptions to childhood vaccines did not have enough support in the Democrat-controlled State Senate to be put up for a vote. The bill would have ended a policy that allows parents in New Jersey to cite religious beliefs as the reason their children have not been immunized, without affecting the child's ability to be enrolled in school.

Weeks of sustained and boisterous protests outside the State Legislature by those opposed to forced vaccination are being touted as the main reason the bill did not go through. The intensity of the prolonged protest was unlike anything in Trenton in over a decade, many longtime lawmakers and lobbyists said.