California lawmakers on Wednesday pushed forward a bill that would ban parents from citing their personal beliefs as a reason to let their school-going children remain unvaccinated.
The measure passed the state Senate health committee by a vote of 6-2, the bill's co-author, Democrat Richard Pan, said in a statement.
"I've personally witnessed the suffering caused by vaccine-preventable diseases, and all children deserve to be safe at school," said Pan, who is also a pediatrician.
"The personal belief exemption is now putting other school children and people in our community in danger."
Pan proposed the bill, which would leave in place medical exemptions to vaccinations, in the wake of a major measles outbreak in the state that began at Disneyland in December.
All told, more than 150 people across the United Sates have been diagnosed with measles in recent months, 126 of them in California.
The outbreak renewed debate over the so-called anti-vaccination movement, in which fears about potential side effects of vaccinations, fueled by now-debunked research suggesting a link to autism, prompted a small minority of parents to refuse them for their children.
The proposal, which must clear several other legislative hurdles before a possible Senate floor vote, prompted roughly four hours of heated discussion that saw several people removed for shouting down lawmakers, the Sacramento Bee newspaper reported.
Detractors of the bill, including Republican senator Jim Nielsen who voted against it on Wednesday, said it tramples on a parent's rights, the Bee reported.
"I have very profound feelings about parental rights and responsibilities and great dismay in American society over the decades how much that parental right, that parental responsibility has diminished," Nielsen said, according to the newspaper.
Measles was declared eliminated in the United States in 2000 after years of intensive childhood vaccine efforts. But in 2014 the country had its highest number of cases in two decades.
There is no specific treatment for measles and most people recover within several weeks. But in poor and malnourished children and people with reduced immunity, measles can cause serious complications including blindness, encephalitis, severe diarrhea, ear infection and pneumonia.
(Editing by Robert Birsel)