One undeniable fact: Most of the recent measles cases have been in people not vaccinated

The proposed laws have been introduced in statehouses by both Democrats and Republicans and include a range of approaches, from requiring schools to post immunization rates to entirely eliminating religious and philosophical exemptions.

The year’s largest measles outbreak has been traced to Disneyland in Anaheim, California where visitors were exposed to the disease in mid-December. The vast majority of cases have been in that state, which allows both philosophical and religious exemptions.

In all, 10 of the 17 states with reported measles cases have allowed parents to opt out of vaccines on philosophical grounds, creating a far easier way out of immunizations than states that only exempt families with extensively documented religious objections or health conditions that preclude vaccinations. Read more  What is measle?