Senate Bill 277, which would bar parents from skipping school vaccination requirements due to personal philosophies, passed its first test in the state Assembly on Tuesday. Policymakers in the Assembly Health Committee approved the bill on a 12-6 vote.

SB 277 would allow only medical exemptions for children entering public school by removing the option to file a personal belief exemption (PBE). The bill would not pertain to families who homeschool or utilize independent study.

As in previous hearings, both proponents and opponents of SB 277 filled up the room to listen to the highly debated bill, which was the only item on the committee’s agenda and spurred nearly five hours of discussion and testimony.

“A [Public Policy Institute of California] poll last week reported two-thirds of Californians say children should not be allowed to attend public school unless they are vaccinated,” said SB 277 co-author Senator Richard Pan, M.D., to committee members. “This majority will not be silent. When more people are hospitalized or die of preventable contagious diseases, they will hold us accountable for denying the science of vaccination if we refuse to act.”

A back-and-forth discussion between Assemblymembers and witnesses on both sides of the issue took up the bulk of the hearing, as the committee did its best to separate the facts about immunizations from the profusion of myths.

Hannah Henry, co-founder of Vaccinate California, assisted in that regard.

“SB 277 is a common sense measure,” she told Assemblymembers. “A basic protection we need to restore in our society so all schools are equally safe for our kids and our communities.”

Others who voiced their support on Tuesday included representatives from the California Medical Association, California Children’s Hospital Association, American Academy of Pediatrics and California State PTA. But many other cities, counties, community groups, and health and education organizations have also endorsed the bill.

The American Medical Association on Monday announced that it also supports stiffer limitations on non-medical vaccination exemptions — a goal of SB 277.

Vaccinations have prevented more than 21 million hospitalizations and 732,000 deaths among children born in the last 20 years. For reducing the burden of infectious diseases, only clean water has performed better, according to the World Health Organization.

However, a reduction in the number of vaccinated children, combined with a rise in the number of outbreaks of vaccine-preventable diseases, has led to a need for the legislation, according to health experts.

“The consequences [of increased exposure] are disease among those who choose not to be vaccinated, but also in those who are vaccinated because, remember, vaccines don’t work 100 percent of the time,” said Dean Blumberg, M.D., chief of pediatric infectious diseases at UC Davis Children’s Hospital. “And, in addition, there are those who are too young to be vaccinated, and they may be infected.”

It is estimated that more than 13,500 kindergartners in California are currently unvaccinated due to the personal belief exemption. A rising number of unvaccinated children for non-medical reasons are a potential threat to the rest of the population, particularly to those who are immunocompromised, such as pregnant women, chemotherapy patients and those with chronic diseases.

SB 277 now moves to the Assembly floor for consideration.