California lawmakers have passed a contentious bill that would impose one of the strictest school vaccination laws in the country after a series of emotionally charged debates.
The Senate on Monday reaffirmed the bill striking California's personal belief exemption for immunizations on a 24-14 vote.
Democratic Gov. Jerry Brown has not said if he would sign it.
California's proposal is intended to boost vaccination rates after a measles outbreak at Disneyland last year. The measure would only allow children with serious health problems to opt out of school-mandated vaccinations.
It has prompted the most heated legislative debate of the year with thousands of opponents taking to social media and protesting legislative hearings.
If the bill becomes law, California would join Mississippi and West Virginia as the only states with such strict requirements.