The number of kindergartners who are not fully immunized was above the state average in three of the five Vineyard towns with elementary schools last year, a fact which worries Island doctors who see the choice of parents to not immunize their child against illnesses such as mumps, measles and rubella as a threat not only to the health of that child but the school community at large.

Last year in West Tisbury 10 kindergartners, or 23 per cent of those enrolled in the West Tisbury elementary school and the Martha’s Vineyard Public Charter School were given exemptions from full vaccination according to the Massachusetts Department of Public Health, which collates data from public school nurses. It is one of the highest rates in the state.

The figures reflect a nationwide rise in unvaccinated children. An important factor in the rise, researchers say, is a widely held but misguided concern over a connection between vaccinations and autism. The theoretical link, first raised in the 1990s, has been extensively debunked — the national Centers for Disease Control, the American Academy of Pediatrics and the Institute of Medicine have all declared that there is no causal link between the vaccine for measles mumps and rubella — which is administered in a single shot — and autism.

Yet a stigma remains.

For towns with fewer than 10 exemptions, figures are rounded off for privacy reasons by the department of health. But Chilmark exemptions corresponded to more than or equal to 10 per cent of the six students.

Tisbury had fewer than five students with exemptions, corresponding to between five and nine per cent of the kindergartners.

Edgartown and Oak Bluffs kindergartens had fewer than five per cent exemptions.

Meanwhile, the Massachusetts average was one per cent overall for the 2007-2008 school year, according to the state. There were 275 medical exemptions and 504 religious exemptions out of 78,000 kindergarten children.

Children entering public schools in America must receive seventeen doses of vaccine for a list of illnesses which includes polio and varicella, or apply for an exemption. In Massachusetts exemptions are granted on two grounds: medical and religious. Some states allow for philosophical objections to the vaccines. In the commonwealth, the clear majority of exemptions fall into the religious category. But since the state does not require that the parent expand on the specific religious belief that clashes which the practice of vaccination, some parents may use the religious exemption to simply circumvent the system.

Dr. Judith Fisher, who runs a family practice at the Martha’s Vineyard Hospital, was on call last year when a child was flown to a Boston hospital with varicella pneumonia, a complication arising from chicken pox. The child had not been immunized against chicken pox.

Dr. Fisher said the risk is not confined to the non-immunized child. For example, she said the measles vaccine has a 95 per cent protection rate for the vaccinated child, meaning that even vaccinated children can still be at risk if exposed to the full-blown illness by an unvaccinated child.

“You’re not just making the decision for you, you’re also making it for others,” Dr. Fisher said, adding:

“With chicken pox there’s a three day lead — by the time you see symptoms it can be too late.”

David Caron, director of pharmacy at the Island hospital, helped create Immunize MV last year, a program designed to educate Island parents about perceived risks associated with the vaccines. Mr. Caron’s group did not conduct scientific research about Island vaccine rates. “We went on impulse for the most part,” he said. But the group did conduct a questionnaire among new parents. The results showed that among those who had doubts about immunization, the most frequent concern was a perceived connection to autism. Another parental concern centers on the presence of thimerosal — which contains mercury — in some vaccines. The institute of medicine has also concluded that there is no casual relation between thimerosal and autism.

Mr. Caron underscored the fact that extensive research shows the fear is unfounded.

“Nothing out there links vaccines with autism or any of these things,” he said. Still, he said, with the health of children at stake, the fear is understandable.

“It’s hard to look parents in the eye and tell them that their child’s autism has nothing to do with vaccinations; it’s an emotional decision. As with anything in life, fear is the greatest prevention. It’s like getting on a plane,” he said.

Mr. Caron said the goal is to give the viruses no room to thrive.

“That’s what we want in the school system,” he said. “Diseases like polio were basically eradicated. But since the onset of parents choosing not to immunize their child, some of these illnesses have been making a comeback. It’s a scary thing to think about. You never used to see things like measles and whooping cough, which is 100 per cent preventable,” he said.

The re-emergence of these childhood illnesses is a national issue. Researchers working on standards set by the Centers for Disease Control declared measles eliminated in the United States in 2000, yet reported cases of measles have more than doubled in 2008. As reported in a New York Times article earlier this year, 12 San Diego children contracted measles in the month of February. All the children were either too young to be immunized or had not been inoculated because of parental objection.

Dr. Fisher said awareness of the dangers of the diseases has declined along with an oral history among women.

“When women my age were having children, the grandmothers would tell all young women that they had children that died or went deaf from these illnesses,” she said. “We all immunized our children.”

The first mass immunization occurred in the United States when soldiers were deployed to fight in World War II.

“They saw firsthand the effects of the diseases they were immunized against. When they came back they insisted that their children get vaccines,” Dr. Fisher said.

But even in the face of most recent medical research, some are not convinced.

Deborah Bermudes runs Massachusetts Citizens for Vaccination Choice with her husband. She said the organization promotes awareness about vaccines but does not advise parents on whether or not to vaccinate.

“Parents want the best for their children. Whether we’re breast feeding, using cloth diapers, organic foods. Immunization is another one of those choices,” she said. She argued medical research on the subject is lacking, but had no comment on the extensive research disproving links between autism and the MMR vaccine.

She said that not everyone subscribes to the dictum that “disease is bad and anything we can do to stop it is good.

“Others think disease is useful in building up immune system process,” she said.

Mrs. Bermudes said chronic conditions such as asthma and allergies are on the rise nationally, adding:

“The question is out there: are we trading one for the other?”