Maine’s schoolchildren last year ranked below the national average in their rate of immunization against preventable childhood diseases, according to a national report recently released by the Centers for Disease Control and Prevention.

The director of the state’s immunization program said the report, taken on its own, has limited meaning, but her office will use it along with other data sources to evaluate the effectiveness of Maine’s program.

In a compilation of school-entry data from 48 states and the District of Columbia, the report, published in last week’s issue of the CDC’s Morbidity and Mortality Weekly Report, compared immunization compliance rates with nationally recommended protocols. Maine’s reporting showed that children entering kindergarten in 2002 were less likely to have received all recommended immunizations than children in most other states.

Surveying data reported on 95 percent of Maine’s approximately 14,600 kindergartners last fall, the CDC focused on the four vaccines it recommends for all children. With one exception, the state requires the vaccines recommended by the CDC and another not included in the study.

Maine schools determined that 88.5 percent of pupils entering kindergarten in 2002 had received the four polio vaccines required. The national compliance average for polio vaccines in kindergartners and first-graders was 96.2 percent. Only Georgia, with a rate of 87.9 percent, and Colorado, with 85 percent, reported lower compliance rates than Maine.

Ninety percent of Maine kids were up to date with their diphtheria-pertussis-tetanus shots, according to the report. The national average was 95.5 percent. Only three states reported lower rates – Wisconsin with 89 percent, Georgia with 87.9 percent and Virginia with 80.3 percent. The CDC recommends and Maine requires five DPTs before entering school.

When they entered school, 89.2 percent of Maine kindergarten pupils had received both of the required measles-mumps-rubella vaccines. The CDC report broke down the vaccines, commonly given together, into their separate components. The national average was 95.7 percent for measles and 96.1 percent for mumps and rubella or German measles.

Unlike many other states, Maine does not require hepatitis B vaccine for schoolchildren, although it is recommended by the CDC.

One dose of Varicella, the chickenpox vaccine, is required for children entering school in Maine but was not one of the vaccines reported in the CDC school study.Most children in Maine also receive an Hib vaccine against influenza although it is not required by the state. The CDC did not include that vaccine in its school survey either.

Lisa Tuttle, director of Maine’s immunization program for the Bureau of Health, said Tuesday that the CDC school-entry report is of limited value and prone to inaccuracies. Because the data is reported by individual schools, she said, there is much room for inconsistency in the reporting.

Of greater use, Tuttle said, is the annual National Immunization Survey, also conducted by the CDC, which surveys the immunization compliance of 2-year-olds, state by state. NIS staff members contact households in a sample population that reflects the demographic makeup and ask parents whether their children are up to date on their vaccines. Parents then are asked to release their children’s medical records to validate the phone survey.

Children who were entering kindergarten last fall would be represented in the 1999 survey of 2-year-olds. When measured with the “more rigorous tool” of the NIS, Tuttle said, Maine children’s compliance with polio vaccine requirements rate is 92 percent, better than the 89 percent national rate. Using the NIS data, Maine ranked higher than average on the other reported immunizations as well, she said.

Tuttle said Maine generally demonstrates above-average compliance with immunization recommendations as measured by the NIS, which she calls “the gold standard.”

However, rates can be affected by a number of variables, she said. In 1999, for example, some parents were reluctant to have their children receive the MMR vaccine because there was speculation it might cause autism. Research since has dispelled those fears, and compliance has gone up.

Tuttle said she would like to see 100 percent compliance with recommended vaccines, but added the goal isn’t realistic. Some children are medically unable to tolerate vaccines. Some parents have a philosophic or religious opposition to vaccinating their children.

“Because these diseases have been largely eradicated, parents have never seen the devastation of polio or measles,” Tuttle said.

Unless they have been granted an exemption, parents who enroll their children in public schools without their immunizations being up to date have a 90-day “grace period” to bring them into compliance. Children from low-income families may qualify for vaccines at a reduced cost or for free, Tuttle said.