Fewer parents in Maine chose not to vaccinate their kindergarten-age children last year for religious or philosophical reasons, although the state’s vaccination opt-out rate remains in the upper tier nationally.

During the 2014-15 school year, an estimated 4.4 percent of children enrolled in kindergarten across the state did not receive vaccinations for such contagious diseases as measles or whooping cough because parents chose to exempt them, according to school survey data released Friday by the U.S. Centers for Disease Control and Prevention. That is down from an opt-out rate of 5.5 percent during the 2013-14 school year.

Maine saw the second-largest decline nationally after Kansas, which experienced a drop of 1.2 percent. Yet Maine was still one of 11 states with opt-out rates at or above 4 percent. Medical professionals warn that “herd immunity” that occurs when almost everyone is immunized begins to break down when less than 95 percent of the population is vaccinated.

Meanwhile, Maine also reported a significant increase in the vaccination rate for children between the ages of 19 months and 35 months – so large an increase, in fact, that Maine jumped from the middle of the pack to the national leader last year.

Maine’s vaccination rate for the series of seven childhood vaccines protecting against 11 diseases was 84.7 percent, compared to 71.6 percent nationally and up from 68 percent in Maine in 2013, according to the latest CDC data.

State health officials cheered the positive news on both fronts.

Tonya Philbrick, director of the Maine Immunization Program at the Department of Health and Human Services, said the state has seen some “extraordinary partnerships” between the state, health organizations, hospitals and doctors at the local level to make vaccines easier to obtain and administer.

“But I really think parents are starting to make informed decisions based on scientific or medical information from their providers,” Philbrick said.

This story will be updated.

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.