New Jersey families will retain the right to claim religion as a reason to not have their children vaccinated, after an eleventh-hour attempt Monday to end such exemptions did not gather sufficient support to bring the issue to a vote.

But Senate backers of the bill vowed to reintroduce it, possibly as soon as Tuesday afternoon, when the new legislative session begins.

“We’re ready to go to war over this,” State Senate President Stephen Sweeney (D., Gloucester) said after Monday’s voting session, according to NJ.com. “We will pass this bill. This is about public health.”

Reintroducing the bill would start the legislative process anew, including likely hearings. Sweeney told reporters Monday that the legislation was one vote short of passage. He said that in the new session, he may convene a hearing, calling on experts from both sides of the debate.

Hundreds of exemption supporters who gathered at the Statehouse cheered loudly from the Senate gallery when the session ended Monday with no vote on the bill.

Sue Collins, cofounder of the New Jersey Coalition for Vaccination Choice, called the bill’s defeat “a victory for both religious and medical freedoms,” reported NJ.com.

It was the second time in about a month that the Senate was poised to vote on the controversial legislation, approved by the Assembly, that could eliminate religious exemptions from childhood vaccinations against infectious diseases such as measles. Had it passed, the only reason to keep a school-age child unvaccinated would have been certain medical conditions.

By the end of last week, it looked like a compromise version might have garnered enough support to pass the Senate. The new version would have had to again clear the Assembly, too.

The amended bill would have allowed private schools and day-care centers to decide whether they wanted to accept unvaccinated students, as long as they notified all students’ families of their policy. Immunization would have been required for admission to public schools, except for medical reasons.

State Sen. Declan O’Scanlon (R., Monmouth) had agreed to support the amended version, giving Senate Democrats what they thought would be enough votes, only to apparently lose another supporter. According to some reports, there were concerns among some lawmakers about the changes to the bill.

O’Scanlon said Monday that he is convinced of the “overwhelming benefit of vaccines” in preventing the spread of infectious diseases, but believed the original bill was “too restrictive” and “overbroad,” giving families who refused to vaccinate just one education option: homeschooling. After Monday’s session, O’Scanlon said he would have voted for the bill, but called its failure democracy “working as it should.”

State Sen. Loretta Weinberg (D., Bergen), cosponsor of the bill, reiterated her commitment to getting the legislation passed.

“Though I understand the passion of those opposed, fundamentally this not a personal choice, and in society it is the duty of healthy members to work together to protect those who cannot protect themselves,” Weinberg said in a statement.

New Jersey would have become the sixth state to allow only medical exemptions from vaccines for public schoolchildren.

The great majority of Americans — around 88%, according to a Pew Research Center poll — agree with vaccinating children but opponents have been increasingly vocal. That is despite gold-standard medical evidence that vaccines are safe and have eliminated diseases that used to kill thousands of American children every year, such as polio.

Earlier this year, a study by the New Jersey Hospital Association found that state families claiming religious exemptions for their children — the state does not allow an exception for “personal belief,” as some do — rose 53% in the last five years. Leaders of virtually all major religions have advised their members to get their children immunized.

This growing debate coincides with recent outbreaks of measles both globally and across 31 states in the U.S. In 2019, there were 1,282 U.S. reported cases of measles, according to the federal Centers for Disease Control and Prevention, including 19 cases in New Jersey and 17 in Pennsylvania.