The New York state Assembly has voted to eliminate a religious exemption to vaccine mandates for schoolchildren in the face of its worst measles outbreak in decades.
The Democrat-led chamber approved the bill Thursday. The Senate plans to take up the measure later in the day.
Similar exemptions are allowed in 46 states. But lawmakers in several of them are also considering eliminating the waiver. Maine nixed its religious exemption earlier this year.
Supporters say misinformation spread by vaccine opponents is creating a public health crisis and putting children who can't get vaccinated for medical reasons at risk.
Gov. Andrew Cuomo says he supports eliminating the exemption.
Hundreds of parents of unvaccinated children gathered at New York's Capitol before Thursday's vote to protest what several called an assault on religious freedom.
"People came to this country to get away from exactly this kind of stuff," said Stan Yung, a Long Island attorney and father.
Yung, who is Russian Orthodox, said he has religious views and health concerns that will prevent him from vaccinating his three young children. His family, he said, may consider leaving the state if the bill is signed into law.
Following the Assembly's 77-53 vote in favor of the bill, opponents erupted in anger, yelling "shame!" One woman standing in the Assembly gallery yelled profanities down on lawmakers, who then recessed for the day.
Supporters of the bill say religious beliefs about vaccines shouldn't eclipse scientific evidence that they work, noting the U.S. Supreme Court ruled in 1905 that states have the right to enforce compulsory vaccination laws. During the Assembly's floor debate, supporters brought up scourges of the past that were defeated in the U.S. through vaccines.
"I'm old enough to have been around when polio was a real threat," said Assemblywoman Deborah Glick, D-Manhattan. "I believe in science.... Your personal opinions, which may be based on junk science, do not trump the greater good.
Supporters also suggest some parents may be claiming the religious exemption for their children even though their opposition is actually based on misguided claims about scientifically discredited dangers of vaccines.
The bill would not change an existing state exemption given to children who cannot have vaccines for medical reasons, such as a weakened immune system.
Once signed, the law will take effect immediately but will give unvaccinated students up to 30 days after they enter a school to show they've had the first dose of each required immunization.
"I understand freedom of religion," Cuomo told reporters Wednesday. "I have heard the anti-vaxxers' theory, but I believe both are overwhelmed by the public health risk."
Federal health officials said last week that this year's U.S. measles epidemic has surpassed 1,000 illnesses, the highest in 27 years. The majority of cases are from outbreaks in New York in Orthodox Jewish communities.
The nation last saw this many cases in 1992, when more than 2,200 were reported.
Legislation is pending in several state capitols to eliminate their version of the religious exemption.
California removed personal belief vaccine exemptions for children in both public and private schools in 2015, after a measles outbreak at Disneyland sickened 147 people and spread across the U.S. and into Canada. Maine ended its religious exemption earlier this year.
Mississippi and West Virginia also do not allow religious exemptions. Once common in the U.S., measles became rare after vaccination campaigns that started in the 1960s. A decade ago, there were fewer than 100 cases a year.