The Maine House of Representatives approved by a wide margin Tuesday a bill that would make it more difficult for parents to forego vaccines for schoolchildren, but the measure did not get enough support to override an expected veto by Gov. Paul LePage.

The 93-53 vote included all Democrats but one, as well as 12 Republicans, voting in favor. But the tally fell short of the 101 votes needed to override a veto by Gov. Paul LePage, who has said he supports parental choice on vaccinations.

Deb Deatrick, senior vice president of community health for MaineHealth, the parent company of Maine Medical Center, and a supporter of the bill, said the measure faces a difficult road to become law.

“We’re within striking distance, but it would be a challenge,” said Deatrick, who expects an intense lobbying campaign in the final days of the legislative session.

The bill requires parents opting out of required vaccinations on philosophic grounds to consult with and have a form signed by a medical professional before being permitted to forego vaccinations required for school. Maine has one of the highest parental opt-out rates in the nation for children entering kindergarten, and public health advocates argue that Maine is at risk for a return of preventable diseases like measles, mumps, polio, chickenpox and pertussis if vaccination rates continue to be weak.

But LePage has expressed his opposition to the bill, arguing that parents must have a choice. Parents can currently opt out on philosophic or religious grounds by simply signing a form. The religious exemption would remain intact even if the bill were approved.

Those opposed to the bill – including some libertarian-minded Republicans – have argued that making it more difficult to opt out for philosophic reasons would infringe upon parental rights. Also, some believe that the risk from vaccines outweighs their benefits, and suspect that the vaccines cause autism. Numerous studies have proven the overwhelming safety of vaccines, and that there is no link to autism.

Counting lawmakers who were absent and expected to be in favor of the bill, proponents need to pick up six votes to have a shot at overriding a LePage veto, Deatrick said.

The Senate, which had yet to vote by late Tuesday afternoon, would also need to first vote for passage and then override a veto in order for the bill to become law.

Deatrick said many public health bills – such as restricting where people can smoke – need several votes spanning many years before they ultimately succeed.

“You have to take the long view with public health,” Deatrick said.

While the state average for kindergarten non-medical exemptions was 3.9 percent for the 2014-15 school year, there are clusters of communities with a much higher percentage of exemptions.

In Maine, at least 60 elementary schools have vaccination opt-out rates of 10 percent or higher, according to school-by-school information released by the Maine CDC last month and published by the Maine Sunday Telegram in an interactive, searchable database.