AUGUSTA — Maine is preparing for a "mass vaccination" of students to guard against the spread of the H1N1 virus and its more common cousin, seasonal influenza, the state's top doctor said Friday.

The Maine Center for Disease Control and Prevention has secured more than 200,000 doses of seasonal influenza vaccine, enough for all of Maine's school children, said Dr. Dora Anne Mills, CDC director.

She's urging parents to see that their children receive the seasonal flu vaccination in September. In October, the state expects to receive a supply of H1N1, or swine flu, vaccine from the federal government, and Maine schools will offer free doses to students.

"It really is important for all children in our schools to be vaccinated," Education Commissioner Susan Gendron said Friday morning at a press conference with Mills and Brenda Harvey, Maine's Health and Human Services commissioner.

That's because swine flu is disproportionately affecting young people.

More than half of Maine's swine flu cases have sickened people – both Maine residents and out-of-staters in Maine – younger than 25, according to Mills. Ninety percent of the cases have struck people 50 and younger, she said.

"That is in vast contrast to seasonal influenza," Mills said.

Administering the vaccine in schools offers the surest bet of immunizing the population most vulnerable to swine flu's spread, she said.

"That's where kids are," Mills said. "If we don't offer it in schools, then they have to go to their health care provider, and that will essentially bottleneck the health care system."

Pregnant women and health care workers are also at risk for contracting the virus, she said.

While health officials are concerned about the virus' spread, Mills said, "there is no reason at this point to mandate vaccination."

Schools are signing up with the state to offer their students swine flu vaccinations, Gendron said. So far, she said, more than 80 districts have signed up, with more expected to enlist before students return to school.

The vaccines will be free to students, with the federal government assuming the tab for the vaccine's development and distribution to states. Health officials are looking into insurance reimbursements to cover the cost to schools of administering the immunization.

"It's a real, coordinated effort of all of our resources," Gendron said.

Maine health officials are likely to make use of lessons from the virus' spread at summer camps.

Thirty-six camps have reported swine flu cases this summer, Mills said, but none had to close.

"We have learned from these camp outbreaks the value of preparation," she said.

Staff members checked campers' temperatures when they arrived for the summer, the New York Times reported recently. And the camps have set aside areas to quarantine infected campers and have taken hygienic precautions.

As the state undertakes its vaccination effort this fall, Mills said, the efforts might not completely stem the H1N1 virus' spread.

"H1N1, we're prepared for a marathon," she said. "I'm not sure how many miles we're into it."