Maine middle and high school students will have to be vaccinated for meningitis starting in the 2018-19 school year.

The new rule will apply to students entering seventh grade and 12th grade, for whom vaccination was previously recommended but not required. Bacterial meningitis is a rare but potentially deadly disease in which the membranes surrounding the brain and spinal cord become inflamed. There is no vaccine for the more common viral meningitis, which has milder symptoms.

“Meningococcal disease (bacterial meningitis) is a rare, but dangerous disease that strikes healthy young people without warning,” said a news alert from the Maine Department of Education. “It can affect all ages, but teens and young adults are at highest risk of getting the disease.”

Symptoms include a stiff neck, severe headaches and fever.

The Maine Center for Disease Control and Prevention reported one case of bacterial meningitis in 2016 – the most recent available statistics for the disease – and typically five or fewer cases per year over the past decade.

Meningitis outbreaks are more likely to occur when people are living in close quarters, such as college dormitories.

Nationally, there were 370 bacterial meningitis cases in 2016, according to the U.S. Centers for Disease Control and Prevention.

“These changes further align Maine’s immunization rules with current national recommendations to better protect the health of all Maine people,” said the Maine Department of Education. Maine’s meningitis vaccination rate for teens ages 13-17 was 83.5 percent in 2016, compared to the 82.2 percent national average, according to the U.S. CDC.

The U.S. CDC strongly recommends vaccination because bacterial meningitis is a fast-moving and potentially deadly disease.

“Doctors treat meningococcal disease with antibiotics, but quick medical attention is extremely important. Keeping up to date with recommended vaccines is the best defense against meningococcal disease,” said the U.S. CDC.

Maine also recently required a pertussis booster shot for students entering seventh grade. Pertussis – or whooping cough – is a persistent public health problem in Maine, with 410 cases in 2017. Sanford schools reported an outbreak, with a total of six cases in the elementary and middle schools, on April 11.

An outbreak is defined as three or more people sickened by an infectious disease in one location, such as a school, church or dormitory. Maine had the third-highest rate of pertussis in the nation in 2016, the latest year national comparisons were available.