Maine will head into the flu season with a fraction of the vaccine doses state health officials ordered back in July. Of an estimated 151,000 doses requested from the federal Centers for Disease Control and Prevention, 123,000 were to have come from the Chiron manufacturing facility in Great Britain and are now unavailable, according to Dr. Dora Ann Mills, director of the state’s Bureau of Health.

British health officials announced Tuesday that Chiron’s license has been suspended for three months because of unspecified contamination at its Liverpool factory. The company has said it will be unable to supply any vaccine to the U.S. market for the 2004-2005 flu season.

That leaves high-risk Mainers with just 28,000 doses manufactured by the Aventis corporation of France, the only other provider of injectable flu vaccine for the United States. The Aventis vaccine, though, is designed for infants and toddlers. It can be used effectively in larger doses for adults, but that will decrease the number of overall doses available, Mills pointed out.

It’s still too early to tell, she said, but it is likely Maine officials will need to implement some sort of rationing system to determine who gets the limited supply of vaccine.

“We’ll need to focus the existing vaccine on the highest-risk people,” she said. The CDC issued a statement Tuesday identifying the high-risk group as infants and toddlers between 6 months and 2 years old, adults 65 and over, women who will be pregnant during the flu season, which generally runs November to March in Maine, and anyone with a chronic medical condition such as asthma or diabetes. Also included in the high-risk category are health care workers with direct patient contact, child care workers, and residents of nursing homes and other residential facilities.

The state Bureau of Health uses public dollars to purchases a supply of flu vaccine each year, which is slated for distribution to low-income, high-risk Mainers. This year, Mills said, the state spent $1.165 million for 150,000 doses – $852,000 from the Fund for a Healthy Maine, $279,000 from a CDC grant, and $34,000 from a childhood immunization fund set up by private insurance companies.

The publicly purchased vaccine is distributed to physicians’ offices and clinics free of charge; providers may charge a small fee to administer the injection. Physicians order additional supplies for their regular-risk patients, usually through private sales representatives. Mills said Tuesday that the state has no way of knowing how much vaccine physicians may have ordered privately or how much of it may have been ordered from Chiron. Officials will conduct an informal, sample survey, she said, in case it’s necessary to ask physicians to prioritize their highest-risk patients.

It takes many months to produce flu vaccine, and though Aventis has indicated it may be able to ramp up production after filling its existing orders, it is unlikely to have a new supply ready before flu season hits in earnest. A third company, MedImmune, which makes a nasal flu spray safe for healthy children over age 5 and adults under 50, has said it cannot provide any more than the 1.5 million doses it had planned to make for this year’s flu season.

Mills, a strong advocate for immunization, said the federal government should be responsible for ensuring adequate supplies of flu vaccines and routine childhood immunizations, rather than allowing private industry to respond to predicted demand.

“It’s tragic that the wealthiest country in the world cannot supply vaccines to the people who need them,” she said. Just as ensuring safe drinking water and highways is a key role for the U.S. government, “vaccines are a critical part of the public health infrastructure,” she said.

Each season’s flu vaccine attempts to predict which strain of the potent virus will be active in a given part of the world. Last year’s formula missed the mark and was feared to have little effect, but Mills said a recent survey showed people who were immunized last year were less likely to get sick, or didn’t get as sick, as those who were not vaccinated.

Flu virus kills more than 35,000 Americans each year and hospitalizes many more. In 1918, a worldwide flu epidemic killed more people than were killed in all of World War II. Mills said it’s “just plain luck” that a similarly virulent strain hasn’t hit again.

Mainers should take two basic steps to protect themselves and others, she said:

. If you are in the high-risk category, call your physician now to make an appointment for a vaccine. Even if the vaccine is in short supply, having your name on a waiting list makes it more likely you’ll be able to get immunized.

. Practice what Mills calls “good respiratory etiquette.” Cover your coughs and sneezes, wash your hands frequently, dispose of tissues promptly, and stay home from work or school if you’re sick.

“These steps sound so simple, but they work,” Mills said. “People keeping their germs to themselves is the first and best line of defense.”