In a stunning turnaround, Maine has gone from the middle of the pack in vaccination rates for 19- to 35-month-old children to the highest in the nation in 2014, according to new figures from the U.S. Centers for Disease Control and Prevention.

Maine’s vaccination rate for the series of seven vaccines protecting against 11 diseases was 84.7 percent, according to a CDC report released Thursday, compared with the national average of 71.6 percent. That’s a 16.7 percentage point increase over the state’s 2013 rate, when Maine’s 68.0 percent coverage was slightly below the national average of 70.4 percent.

Public health advocates applauded the improvement but cautioned that Maine’s opt-out rate for children entering kindergarten was fifth highest in the nation in 2013-14, at 5.2 percent. Although that rate declined to 3.9 percent for the past school year, it was likely still among the highest in the country. The national data for 2014-15 haven’t been released yet by the CDC.

“We knew it would take a lot of work and time to raise the immunization rates,” said Dr. Amy Belisle, a pediatrician and the medical director with Maine Quality Counts, a nonprofit regional health care collaborative. “But this has been a very sustained effort. That’s why everyone was dancing today.”

Maine was above the national average for at least five of the vaccines: 97.2 percent to 91.5 percent for the measles, mumps and rubella (MMR) shot, 93.1 percent to 84.2 percent for the diphtheria, tetanus and pertussis (DTaP) vaccine, 73.0 percent to 72.4 percent for hepatitis B (HepB), 62.1 percent to 57.5 percent for hepatitis A (HepA), and 75.4 percent to 71.7 percent for rotavirus.

“This is a tremendous accomplishment for all of the individuals and organizations in public health, medicine, government and health insurers who have worked with families to get necessary vaccines on time over the last five years,” Belisle said in a written statement Thursday night.

Maine improved on its 2013 immunization rate by 6.2 percentage points for MMR, 5.2 points for DTaP, 4.1 points for HepB, 4.7 points for HepA and 3.4 points for rotavirus.

Belisle said her organization has worked directly with more than 20 medical practices since 2011 to educate and raise awareness about the benefits of childhood immunizations.

North Carolina had the second highest immunization rate for the series of vaccines at 80.8 percent. West Virginia was lowest at 63.4 percent.

The issue of whether to have a child vaccinated against diseases such as measles, mumps and rubella has been extensively debated in the Maine Legislature.

A bill to require that parents consult with and get a signature from a medical professional before opting out of vaccinations for their children on philosophic grounds was vetoed this year by Gov. Paul LePage, who said the bill infringed on parental rights. The veto fell five votes short of an override in the Maine House.

Some parents have been reluctant to have their children vaccinated, signing a form that allows them to opt out on religious or philosophic grounds.

Part of the reason some parents have become worried about vaccines is because of a study from 1998 – which has since been debunked – that claimed there was a link between autism and vaccines. The study was retracted and thousands of subsequent research papers have disproved any connection.

Public health officials say vaccinations are more than just a personal choice, because of the effects on the community. Greater percentages of unvaccinated people can weaken herd immunity and spread diseases not only to other unvaccinated people, but also to those too young to be vaccinated and those who have weakened immune systems from other illnesses.

Last year, Maine ramped up its efforts to educate the public about the importance of vaccinations after an outbreak of measles at Disneyland sparked a national debate about immunizations. That outbreak started in California and spread to 14 states, sickening more than 100 people.

“I’m very confident that this is an upward trend. It’s an indicator that the efforts being made in Maine are being reflected in the data,” said Tim Cowan, director of the health index initiative for MaineHealth, the parent company of Maine Medical Center in Portland.

Deborah Deatrick, MaineHealth’s senior vice president for community health, is also a member of the Maine Vaccine Board, which facilitates the purchase of vaccines for the state’s children. By collecting payments from health plans and insurers and remitting those funds to the state, it helps make it possible for physicians, clinics and hospitals to receive vaccines at no cost.

Deatrick said the figures released Thursday by the CDC are encouraging.

“I think it’s due to a combination of parents becoming more aware of the downside of not letting their child get immunized and the state improving access to vaccines,” she said.

Deatrick said pediatricians and doctors have pitched in as well. Better education and training have allowed medical providers to help parents understand the importance of immunizations.

“These numbers prove that the majority of parents are doing the right thing in terms of protecting their kids,” she said.