More H1N1 influenza vaccine will be available for people in high-risk populations during a community clinic on Monday.

Health officials hope to vaccinate 1,200 people at the Shrine Auditorium during what will be the sixth walk-in vaccination clinic held in Billings.

Pregnant women, caregivers of or people who live with children younger than 6 months old, healthy people from 6 months to 24 years old, health care and emergency services personnel, and people age 25 to 64 with chronic medical conditions are eligible for the vaccine.

Inoculations will begin at 1 p.m. and continue on a first come, first-served basis until 7 p.m. or until the vaccine supply runs out. Last week, all 1,500 doses that were available were administered by 7 p.m.

“I don’t believe anybody waited more than 15 or 20 minutes,” said Barbara Schneeman, spokeswoman for RiverStone Health, the county health agency.

Nurses screen people as they arrive for eligibility and to determine which type of vaccine they should receive. There is no charge to be vaccinated.

The H1N1 influenza vaccine has been limited to people in priority groups because there is not enough available for everyone.

The priority groups were selected by the Centers for Disease Control and Prevention based on data showing that people in those populations were most at risk of falling seriously ill or dying from H1N1 flu infection.

H1N1 is a new strain of influenza A that was identified in Mexico in March and has since spread around the world. It has not proved to be more contagious or deadly than other strains of flu.

Yellowstone County reported its first confirmed case of H1N1 influenza in early May. The virus is still circulating in the community.

People in priority groups who have already had the flu this fall should still be vaccinated because they can’t know for sure that they had H1N1 flu, Schneeman said.

“It’s only those people who had Montana State Lab confirmed cases of H1N1 who do not need the vaccine,” she said.

County health authorities plan to hold booster clinics next month for children who need second doses of the H1N1 vaccine.

Kids younger than 10 who received a dose of flu mist need a second dose no sooner than 28 days after the first one. Some children who received an injected vaccine also need a booster.

Reminders cards will be mailed to children who need second doses.

Meanwhile, there is still a shortage of seasonal influenza vaccine. Manufacturers postponed producing the seasonal vaccine to focus on the H1N1 vaccine.

Schneeman said seasonal influenza has not yet been reported in Yellowstone County this fall. The local flu season typically beings in late December or early January.

Contact Diane Cochran at dcochran@billingsgazette.com or 657-1287.