SACRAMENTO ( — State senators have passed a controversial bill aimed at increasing California’s school immunization rates.

The bill approved Thursday would prohibit parents from seeking vaccine exemptions for their children because of religious or personal beliefs.

READ MORE: SAG-AFTRA Calls On Golden Globes Group To Increase Diversity

SB277 by Democratic senators Ben Allen of Santa Monica and Richard Pan of Sacramento would make medical waivers available only for children who have health problems, forcing unvaccinated children to be homeschooled.

California would join Mississippi and West Virginia as the only states with such strict requirements if the bill becomes law.

Red-shirted opponents, some with fussy children, crowded the public gallery to watch the nearly hour-long Senate debate.

READ MORE: Man And Woman Shot To Death In Gardena Identified

Senators approved the measure on a 25-10 vote, sending it to the Assembly. Gov. Jerry Brown has not taken a position on the bill.

Southland parents and other protesters gathered earlier this week in downtown Los Angeles to rally against the bill, with some parents saying they believe the data on vaccine safety is anything but conclusive.

“Our approach to vaccination is it’s ‘one size fits all’, but we all have different genetic makeup,” said protester Alan Hysinger. “We all have different abilities to accept and withstand the toxins that are inherent in vaccines.”

MORE NEWS: Search Underway For 3 Suspects In Glendale Robbery

(TM and © Copyright 2015 CBS Local Media, a division of CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)