“To prevent measles from spreading with herd immunity, you need 90-95 percent of people vaccinated"

"After a Disneyland measles outbreak last year sickened people with a disease typically associated with years long gone, the California legislature put a stop to the personal belief vaccine exemption that allowed parents to refuse immunization for their children on the grounds they disagreed with the requirement or questioned the need or safety of the vaccine. 

With the return of a disease once thought eradicated in the U.S., a Massachusetts bill is now moving to bring in what California just ruled out. 

Federal and state laws mandate all children must be vaccinated to enter school, with some exceptions. In Massachusetts, parents can opt their children out or delay vaccination for only medical or religious reasons. A bill proposed by Joan Lovely, D-Salem, on behalf of a constituent, would add personal belief exemptions to state law."

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