A California bill that would remove the personal belief exemption clause allowing parents to skip child vaccinations required by schools won its first battle in the state legislature on Wednesday.

Senate Bill 277 (Pan, D-Sacramento), which would allow only medical exemptions from school vaccine requirements, passed 6-2 in the Senate Health Committee after hours of emotional testimony. The bill does allow families who home-school to be exempted from the requirements. Among its vocal supporters were health, education and science professionals. They were joined by parents, health care advocates and community members who support vaccination.

“Let me be clear: SB 277 does not mandate vaccinations,” said Senator Richard Pan, M.D., in the packed committee chambers. “But that choice requires responsibility, and we have the responsibility to protect all children attending school by requiring vaccination when children go attend school with other children.”

The bill received strong opposition both at the meeting and at a rally earlier that day, where protestors claimed the proposal would take away parents’ rights and claimed some children were harmed by vaccinations. Some of the protestors were removed during the hearing for shouting during the public comment period.

However, Dr. Pan emphasized that vaccines are safe and efficacious. They have prevented more than 21 million hospitalizations and 732,000 deaths among children born in the past two decades.

“Evidence shows that the disease that’s being prevented by vaccination is at least 1,000 times more likely to cause a lasting problem than the vaccine itself,” he said in front of the health committee. “And there have been no confirmed deaths caused by the measles vaccine.”

While California’s overall opt-out rate is less than 3 percent, some schools have an opt-out rate of more than 50 percent, said Dean Blumberg, M.D., who testified on behalf of the California Medical Association and American Academy of Pediatrics.

“Unfortunately there is much misinformation about vaccine safety and effectiveness,” Dr. Blumberg said. “Let me be clear: there is no scientific controversy about vaccine safety and vaccine effectiveness. The science is clear on this. This is a fact. It’s not open to dispute among mainstream doctors and scientists.”

After spending roughly four-hours on the topic, the health committee chose to push the bill through with dissenting votes from Senators Jim Nielsen (R-Gerber) and Richard Roth (D-Riverside), while Senator Ed Hernandez (D-West Covina) abstained. The bill now moves on to the Senate Educate Committee on Wednesday, April 15.