Maine has experienced a record number of chicken pox outbreaks in the 2014-15 school year, and in most cases the virus has infected unvaccinated or under-immunized children, according to the Maine Center for Disease Control and Prevention.

Four outbreaks started at a school or day care facility in Maine this school year, the most since the vaccine became a requirement for entrance to school in 2003.

An outbreak is defined as three or more cases occurring in one school or day care. Overall, Maine has had 84 cases so far this school year, nearly double the number during the 2013-14 school year. Of those 84 cases, 57 occurred in unvaccinated or under-vaccinated children, according to data released last week by the CDC.

The CDC did not identify the school districts where the outbreaks occurred, saying that was against policy because it is not in the public interest to make that information public, said CDC spokesman John Martins. None of the outbreaks is ongoing, according to the CDC.

But Dr. Laura Blaisdell, a Yarmouth pediatrician who researches vaccines, said that since Maine’s vaccination rates have fallen in recent years, driven by parents who voluntarily opt out of the vaccines for their children, the state should consider releasing the names of school districts where outbreaks occur.

She said it would be helpful to people who live in the community to know where the outbreaks happen, even if they don’t have school-age children, because chicken pox can be contracted at any age, and can be more severe with age.

“Knowledge is power, and the more the community knows about these outbreaks, the better,” Blaisdell said. “We have to change our strategy now that we are at risk of these infectious diseases coming back.”

LIFE-OR-DEATH ISSUE IN SOME CASES

For the Jones family of Alna, the varicella vaccination rate among children in the community is a life-or-death issue. Noah Jones, 16, has leukemia and his immune system is suppressed. If he were to come down with chicken pox, he would likely have to stop his chemotherapy treatments, undermining his recovery.

Children with cancer who contract varicella also can develop complications and die.

“It’s absolutely frightening,” said Noah’s mother, Cathy, who noticed an outbreak of chicken pox this winter in their Lincoln County community, forcing them to be extra careful about whom they associated with, and avoiding some public events.

“None of this is playing around. Noah has one shot at remission and staying disease-free,” she said.

Adults who were not vaccinated as children and never came down with chicken pox – the vaccine wasn’t introduced until 1995 and did not become a school requirement in Maine until eight years later – can still be vaccinated. Before the vaccine was introduced, about 10 percent to 15 percent of the population had never contracted chicken pox as children, according to the U.S. Centers for Disease Control and Prevention.

Maine has one of the highest rates in the country of parents forgoing vaccines for their children, with most opting out on philosophic grounds. Parents often choose to opt out because they fear their children will be injured by the vaccine, or that the vaccines cause autism. But numerous studies have shown that vaccines do not cause autism and are overwhelmingly safe.

Chicken pox used to sicken 4 million children per year, with 10,000 needing to be hospitalized, but that number has dropped by more than 90 percent since the vaccine was introduced, according to the federal CDC.

CHARTING THE UNVACCINATED RATES

State lawmakers are considering a bill that would make it more difficult to opt out of vaccines required for school, by mandating that parents first get a consultation and signature from a medical professional.

According to school-by-school data released last month by the Maine CDC, the distribution of unvaccinated children in the state is uneven. Maine has an overall voluntary opt-out rate of 3.9 percent, but some individual schools have much higher rates, with clusters of parents who live near each other and decide against vaccinating their children. About 60 elementary schools in Maine have more than 10 percent of their kindergartners or first-grade students opting out of vaccines.

In some cases it’s much greater, especially when looking at rates of individual vaccines.

For instance, in Great Salt Bay Community School, the public elementary school near the Jones family, only 26 percent of first-graders have received both doses of the varicella vaccine this school year, according to the database.

The Jones children attend private school, but it’s a small community and they are often around public school children, Cathy Jones said.

‘HERD IMMUNITY’ HELPS PROTECT ALL

Statewide, about 90 percent of schoolchildren get all the required doses of the varicella vaccine, said Dr. Christopher Pezzullo, Maine’s chief health officer, which is below the national average. That puts the state at risk for outbreaks.

“The concern for us is that we have 90 percent coverage for the chicken pox vaccine, which leaves us with 10 percent of the children who are susceptible,” Pezzullo said. “The number of children being immunized for varicella is not going up. It’s remained flat.”

When almost all of a population is vaccinated – usually 95 percent or greater – “herd immunity” is achieved, in which the high number of vaccinations protects the unvaccinated and immune-compromised populations from preventable diseases.

Blaisdell said that those fearful of vaccines often skip varicella because chicken pox is generally not as dangerous as measles or polio.

“Parents, when they’re making vaccine choices, consider varicella a ‘may have’ and not a ‘must have’ vaccine,” Blaisdell said. Some parents, she said, even ask about “chicken pox parties” to intentionally expose their children to varicella, in hopes they contract the disease and obtain natural immunity.

DANGER TO PREGNANT WOMEN, BABIES

Blaisdell said healthy children will most likely recover from the disease without any lasting complications. But if chicken pox spreads through the community, it could sicken those with compromised immune systems, babies too young to have had the vaccine or unvaccinated adults who never got the disease as children. For those populations, chicken pox could be a severe illness, she said.

Chicken pox also can cause complications for pregnant women, especially closer to birth, because it can cause life-threatening infections in a newborn.

Cathy Jones said her family lived in fear of the chicken pox for weeks this winter, when cases occurred at Noah’s school at Lincoln Academy, and in other schools or among people she knew. In a few cases, parents vaccinated their children after hearing about Noah’s condition, and she’s grateful for that. But she said there’s still far too many who opt out of vaccines.

“We’re relying on the community to keep Noah safe,” Jones said. “You can’t live in a bubble, but it’s scary sometimes.”