School systems are rushing to comply with new vaccine requirements aimed at preventing older children from contracting chickenpox.

As part of a new rule change that will be implemented over five years, students in kindergarten and first, second and ninth grades must show either a certificate of vaccination against chickenpox, also known as varicella; documentation of a blood test showing immunity to the disease; or a note from a health care provider that the vaccine is medically inadvisable or that the student has had chickenpox.

Students who do not comply within 90 days will not be allowed in school.

Ensuring that ninth-graders are protected against chickenpox is particularly important because they are entering the age group that puts them at high risk for severe complications from the disease, Dr. Dora Anne Mills, director of the Maine Bureau of Health, said Thursday.

For children and adults over age 13, chickenpox is a serious issue that can be life-threatening to those with conditions such as asthma, cancer and skin disorders, she said.

But because the chickenpox vaccine wasn’t licensed until 1995, many older children haven’t been immunized.

“Parents are used to bringing younger kids into their well-child checks,” said Lisa Tuttle, director of the immunization program at the Maine Bureau of Health. “But adolescents tend to receive health care less often than younger children and probably than even adults.

“It’s a really good thing that people are focusing on preventive health issues for adolescents,” Tuttle said. Schools might be “scrambling” a little with the new recommendations, but “what we know nationally is that [older children] can fall through the cracks as far as immunization and appropriate preventive health checks.”

Last year, children entering kindergarten and first grade needed to show protection against chickenpox to be admitted to school. By 2007, the requirements will be expanded to all grades.

The Maine Department of Health and Human Services is working with the Maine Department of Education and school nurses to answer questions from parents and help with documentation.

In addition, the Bureau of Health worked with teenagers from Washington County to produce public service announcements airing this week telling their peers about the importance of getting vaccinated against chickenpox.

Officials from Brewer and Old Town schools said Thursday that notice about the new requirement had been given to eighth-graders last year, and that the heads-up had helped move the process along.

At Brewer High School, nurse Cathryn Sherman said at least half to three-quarters of the 300 ninth-graders had provided adequate documentation.

Old Town Superintendent Matthew Oliver said, “We’re grateful for the 90-day extension and fully expect we’ll be in compliance.”

More information is available by calling the Maine Immunization Program at (800) 867-4775 or by visiting the Web site: www.immunizeme.org.