MONMOUTH – State health officials are investigating an outbreak of chickenpox at Monmouth’s elementary and middle schools.

Many of the children who contracted the disease had apparently been vaccinated against it.

“We’re looking into that,” said Dora Mills, head of the Maine Bureau of Health.

Chickenpox is a childhood disease that causes a red, itchy rash and a fever. It is transmitted through the air and is highly contagious.

Common in decades past, chickenpox outbreaks have occurred with less frequency since a vaccine was licensed for use in the United States in 1995. Many children now get the shot when they’re about a year old.

Maine began requiring a chickenpox vaccine for schoolchildren a couple of years ago. Kindergartners and first-graders are required to show proof of immunization in order to enroll in school.

In Monmouth, school officials say many Henry L. Cottrell School and Monmouth Middle School students received the vaccine. But nearly 40 kids from kindergarten though grade four have come down with the chickenpox over the past two weeks.

Although such outbreaks do happen a couple of times a year in Maine, the Maine Bureau of Health is investigating. So far, Mills said, it looks like Monmouth’s outbreak is an ordinary flare-up.

Many schools believe their children have been vaccinated, but medical records eventually reveal they haven’t, Mills said. And for those children who did get the shot, contracting chickenpox is unusual but not unheard of. The vaccine is 80 to 90 percent effective.

“This does not appear to be a new strain,” Mills said.

The children who got chickenpox were kept home for a week or more. No new cases have been reported since late last week.

Of the 4 million people who get chickenpox every year, 11,000 are hospitalized and 100 die from it. Children can develop serious complications, including pneumonia and staph infections. Symptoms are supposed to be milder for the 10 to 20 percent who have been vaccinated.

Although some parents believe too many vaccines are harmful, the Centers for Disease Control recommends children get immunized against at least 11 different diseases, including chickenpox.

According to Mills, medical officials across the country are now talking about boosting the chickenpox vaccine’s effectiveness by giving children two doses instead of one.

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