The Maine Senate voted Tuesday to approve a bill that would end exemptions granted for religious and philosophical reasons.
This bill is moving forward by only one vote. The Senate split 18-17 in backing the end to the state's religious exemption law.
Opponents maintain ending the exemption could violate parental rights and push families out of the state.
Health officials have said exemptions could endanger children who can't be vaccinated for medical reasons.
"It makes no sense to allow someone to get out of this because they have a so-called religious belief when we know from Vermont that the rates of people that had philosophical exemptions when they no longer had them, they all switched to religious exemptions," said Andy Schmidt of Maine Families for Vaccines.
The bill will now go through another round in both the House of Representatives and the Senate before it is handed over to Gov. Janet Mills, whose administration has shown support for the bill in the past.
If the legislation is passed, Maine will become the fourth state to stop religious exemptions for vaccinations.