But physicians who practice adult medicine say supplies are scarce, and some pharmacies, including those of Kroger, almost exhausted their supplies this week.

That means most at-risk adults face a challenge in getting immunized this fall.

Those include people over 65, pregnant women and people with chronic diseases.

It won't be impossible, but not easy, either.

The vaccine shortage is a serious issue for the 95 million adults and children who fall into these high-risk categories, almost one-third of the population.

Last year, 83 million Americans were vaccinated, the highest number ever. But flu complications still killed about 36,000 people in the United States and put more than 200,000 in the hospital.

The U.S. Centers for Disease Control and Prevention strongly urges healthy people to forgo the vaccination this year so those most in need can get the shot. During past shortages, doctors have heeded similar calls for voluntary rationing, federal officials say.

Healthy people looking for an alternative can try FluMist, the nasal spray prescribed for people ages 5-49.

"What a mess," said Dr. Steven Englender, an epidemiologist with the Cincinnati Health Department. "Let's hope we have a mild flu season."

People who need the flu shot this year should go where they normally go and ask about the current supply, health officials say.

Most flu immunizations are given in private settings, including doctors' offices, pharmacies and businesses that offer the vaccine to employees. About 10 percent to 20 percent are done in public clinics by local health departments.

The nation's flu vaccine supply was cut in half this week when Chiron Corp., a United Kingdom-based manufacturer, had its license suspended by British regulators because of manufacturing problems. About 46 million doses of the Chiron vaccine had been destined for the United States.

Chiron is generally the vaccine of choice for physicians who practice adult medicine because it's formulated for older people.

These physicians are facing a vaccine crisis, said Dr. Robert Fitz, a primary care physician in Union, Ky., who treats both children and adults. Fitz doesn't expect to see the 800 doses that he ordered from Chiron. His only salvation is a 100-dose supply of a flu vaccine made by French-based Aventis Pasteur that can be used for both young children and adults.

"We're going through our medical charts and identifying our highest-risk patients. They'll be offered what little we have," Fitz said.

Despite the shortage, some locales already have the vaccines. They largely ordered the vaccine from Aventis.

"As far as my practice is concerned, I have enough to vaccinate the people who need it," said Dr. Kevin Kelly, a pediatrician in Edgewood. He received 900 doses from Aventis in mid-September.

The Butler County Health Department, which began the week with 2,350 doses, conducted public immunization clinics for high-risk individuals Thursday at a West Chester senior center and at the Fairfield VFW. More than 800 shots were given at the VFW alone.

"People lined up early. They were waiting for us," said Patricia Burg, the county's health director.

Other local health departments, including those in Hamilton County and Northern Kentucky, are postponing flu clinics until later this fall, when they hope to learn more about future Aventis shipments.

Kroger, which began offering flu shots Monday, one day before the shortage was announced, has used up 90 percent of its supply, company spokesman Gary Rhodes said.

Remaining doses will be given to at-risk populations only, Rhodes said. Other pharmacies, including Walgreens, are following the same policy. The best advice for patients who still have questions is to call their doctor, health officials said.

In the meantime, the U.S. government is taking other steps to ease the shortage:

•  CDC is working with Aventis to alter its remaining flu-shot distribution so that shipments also go to parts of the country that had depended on Chiron's supplies.

• The Food and Drug Administration, along with the National Institutes of Health, are studying whether Aventis' vaccine could be diluted to get two doses out of each original shot. An NIH study several years ago suggested doing so could provide enough protection for healthy people.

E-mail mleingang@enquirer.com