An effort to end exemptions from childhood vaccinations on the basis of religious beliefs in New Jersey won approval in the state Assembly on Monday, only to be halted that night in the Senate after vigorous protests.

The Assembly passed the controversial change by a 45-25 vote with six abstentions.

But later Monday, Senate cosponsor Joseph Vitale (D., Middlesex) said he was one vote short of passing the bill, and Senate President Stephen Sweeney (D., Gloucester) ended the session without bringing up the measure, reported NJ.com.

Sen. Joseph Lagana (D., Bergen) was overheard telling Vitale that he wouldn’t vote yes because it is “just too personal for me," according to NJ.com. Lagana’s three children are all current on their vaccines, his office said later, and his concerns are related to the policy, not vaccine science.

Sweeney later said he would bring up the bill again in the coming weeks.

“They can cheer all they want," he said of the hundreds of people gathered to protest the exemption effort, who erupted in cheers when he called off the vote. "This bill is going to get done. This is good public policy. There is no science to back up what these people are saying.”

If the measure were approved and signed by Gov. Phil Murphy, New Jersey would become the sixth state to enact legislation requiring children in public schools to be vaccinated unless they have medical reason to not do so. New York, California, Maine, Mississippi and West Virginia have already acted to limit exemptions, and other states are considering it, according to the Pew Research Center.

Hundreds of parents, some with their children in tow, thronged the Statehouse in Trenton on Monday, as they did Thursday at a Senate hearing to register opposition to what they called an infringement on their religious freedom.

Supporters of the change showed up at last week’s hearing, too, arguing limiting vaccine exemptions helps to protect public health.

The vast majority of states, including New Jersey and Pennsylvania, allow families to opt out of immunizing their children based on religious objections, even though leaders of the major religions say they support vaccinating youngsters.

In addition, about 15 states including Pennsylvania, but not New Jersey, also allow exemptions based on personal beliefs.

New Jersey’s legislative action comes at a time when more people are questioning the need for and safety of vaccinating children, even though all gold-standard medical evidence indicates that vaccines are safe interventions that have stopped diseases that once killed thousands of American children each year. A study by the New Jersey Hospital Association released earlier this year found New Jersey families claiming religious exemptions for their children rose 53% in the last five years.

The growing vaccination reluctance comes at a time when outbreaks of measles have spread global and across 31 states in the United States. Nationally there were 1,276 measles cases in the U.S. so far this year, according to the federal Centers for Disease Control and Prevention, including 19 in New Jersey and 17 in Pennsylvania.

In an email, Barrington parent Donna Camardo wrote that she believes some vaccines are not safe, but there is a higher principle here.

“Regardless of where you are pro-vaccine or anti-vaccine, the bottom line is that we are being stripped of a right guaranteed by our Constitution, and politicians are ignoring that,” she wrote.

Neal D. Goldstein, a Drexel University assistant research professor of epidemiology, said getting rid of New Jersey’s religious exemption would be “a step in the right direction” that would increase immunization rates.

“But it is also not the magic bullet to ending the vaccine debate here or elsewhere,” Goldstein said. “Along with legislation, there should be continual education and outreach by all stakeholders involved to ensure that only true medical exemptions are granted and citizens are not attempting to subvert the spirit of the legislation, for example by removing their children from school.”