California lawmakers on Thursday approved one of the toughest mandatory vaccination requirements in the nation, moving to end exemptions from state immunization laws based on religious or other personal beliefs.

The measure, among the most controversial taken up by the Legislature this year, would require more children who enter day care and school to be vaccinated against diseases including measles and whooping cough.

Those with medical conditions such as allergies and immune-system deficiencies, confirmed by a physician, would be excused from immunization. And parents could still decline to vaccinate children who attend private home-based schools or public independent studies off campus.

It is unclear whether Gov. Jerry Brown will sign the measure, which grew out of concern about low vaccination rates in some communities and an outbreak of measles at Disneyland that ultimately infected more than 150 people.


“The governor believes that vaccinations are profoundly important and a major public health benefit, and any bill that reaches his desk will be closely considered,” Evan Westrup, the governor’s spokesman, said Thursday.

If the bill becomes law, California will be the 32nd state to deny exemptions grounded in personal or moral beliefs, but only the third to bar exceptions based on religious convictions, according to the National Conference of State Legislatures.

Medical experts, including Dr. Luther Cobb, president of the California Medical Assn., hailed Thursday’s vote by the state Assembly as key to keeping deadly but preventable diseases in check.

“We’ve seen with this recent epidemic that rates of immunization are low enough that epidemics can be spread now,” Cobb said. “The reasons for failing to immunize people … are based on unscientific and untrue objections, and it’s just a good public-health measure.”


“People think these are trivial illnesses,” he said. “These are not. People die from measles.”

The measure, which had passed the state Senate but must return there for the expected approval of minor amendments, sparked impassioned debate among lawmakers and the public.

The dispute has sometimes been acrimonious.

Sen. Richard Pan (D-Sacramento), a pediatrician and an author of the bill, has received death threats. And opponents of the proposal have filed papers with the state to initiate the process of recalling Pan and Sen. Bill Monning (D-Carmel), a vocal supporter, from office.


Hundreds of parents besieged the Capitol during a series of legislative hearings to oppose the bill in the belief that vaccines are unsafe, that the proposal would violate their privacy rights and that they alone — not the state — should choose whether to vaccinate their children.

More gathered for the vote on Thursday.

“This bill puts the state between children and parents regardless of your

position on vaccination,” said Luke Van der Westhuyzem, a parent from Walnut Creek who was among dozens of protesters at the Capitol.

Assemblywoman Lorena Gonzalez (D-San Diego), who voted for the measure, said she understood the personal nature of parents’ decisions about their children’s health.


“While I respect the fundamental right to make that decision as a family,” Gonzalez told her colleagues, “we must balance that with the fact that none of us has the right to endanger others.”

Assemblyman Mike Gatto, a Glendale Democrat, voted against the bill, saying it violated parental rights.

“The broadness of this bill likely dooms it from a constitutional standpoint,” Gatto said, accusing the state of “infringing on the rights of children to attend school.”

More than 13,500 California kindergarten students currently have waivers based on their parents’ beliefs. A parent group, A Voice For Choice, found Thursday’s vote “unsettling,” spokeswoman Christina Hildebrand said.


If Brown signs it, she said, her organization plans to challenge the measure in court or with a referendum.

“We are pulling out all the stops,” she said. “This bill is unconstitutional.”

Dr. Catherine Sonquist Forest, medical director of the Stanford Health Care clinic in Los Altos, said immunizing more people is essential to protect babies too young to receive vaccines.

“This isn’t a question of personal choice,” Forest said. “This is an obligation to society.”


Forest is caring for a 4-year-old boy dying of a rare complication of measles that infected his brain. He was infected when he was 5 months old and too young to be vaccinated.

Ariel Loop is a Pasadena mother whose 4-month-old boy, Mobius, contracted the measles during the Disneyland outbreak. She expressed relief that lawmakers approved the proposal.

“I’m hoping Jerry Brown does the right thing and signs it once it gets through the last Senate [vote],” Loop said.

The bill, SB 277 by Pan and Democrat Benjamin Allen of Santa Monica, passed the Assembly on a bipartisan 46-to-31 vote.


patrick.mcgreevy@latimes.com

Twitter: @mcgreevy99

ron.lin@latimes.com

Twitter: @ronlin

Times staff writer Kurt Chirbas in Sacramento contributed to this report.