AUGUSTA, Maine (AP) A new vaccine law reducing opt-outs for students went into effect Wednesday, ahead of the start of school for most students.

Mainers voted last year to keep the state law that restricts exemptions on childhood vaccinations. The law removes philosophical or religious exemptions for vaccinations for students.

Before the law, Maine’s vaccination opt-out rate for kindergarteners was three times higher than the national average, and officials warned that the measles, mumps and rubella vaccination rate among kindergarteners had dropped below 94%. That’s below the needed “herd” immunity level of 95% immunization, state officials said.

The new law requires traditional childhood vaccinations for students at public and private schools and universities, including nursery school, unless they have a medical exemption.