In October and November Americans stood in line for hours to get one of the precious few flu shots. But now that more vaccine is available — with a few million more doses expected from British and German suppliers — demand is dwindling.

Rod Watson had to cancel 1,000 flu-shot clinics in four states when the national vaccine shortage cut off his supply two months ago. Now Watson has flu shots aplenty — and he can't give them away.

"My biggest fear is I'm going to end up with a lot of serum, and there's a national shortage," said Watson, president of Prevention MD, a medical screening and immunization company. He offers $20 flu shots Monday through Friday at his Seattle-area office.

Public health officials in California, Colorado and other states have voiced similar fears. Some are relaxing the rules to offer shots to more people.

"It's one of those things like Beanie Babies or something," said Doug McBride, spokesman for the Texas Department of State Health Services. "If you can't get something, you've got more people wanting them."

Supply exceeds demand in some areas, the federal Centers for Disease Control and Prevention acknowledges. In other areas, people are still desperate for the vaccine. The best way to find a flu shot is to call your local health department, the CDC advises.

The CDC says 98 million people need the vaccine this winter. About 65 million doses will be available in the United States, including a nasal vaccine that's safe only for healthy people.

Public health officials say they hope demand is dwindling because they've reached the people who need flu vaccine the most: babies, the aged and the infirm. But they acknowledge that other factors — from frustration and apathy to simple human nature — might be at work too.

When something is scarce, people naturally want it more. Being told they can't get a desired immunization is an unfamiliar and unwelcome sensation for most Americans.

"Anytime a commodity is scarce, and it is a desired item, demand will increase," Dr. Louis Manza, psychology professor at Lebanon Valley College in Pennsylvania, said in an e-mail.

Some people probably gave up after trying unsuccessfully to get a flu shot, said Mary Selecky, director of the Washington State Health Department and member of a national advisory group on flu vaccine distribution. Recent reports on this flu season's mild start may have convinced others that getting a flu shot wasn't worth the trouble — an impression Selecky is trying to erase.

"It's a mild flu season up to now, but next week could be another story," Selecky said. "As a society we're driven by what's in front of us ... We're having to work a little bit harder so people know that getting a flu vaccine in December and January is still very effective."

David Marks was surprised at how easy it was to get vaccinated at a Seattle grocery store last week. The line in the express checkout lane was longer than the line to get flu shots.

"I just assumed it was going to be hard," said Marks, 44, whose severe asthma puts him in the high-risk group. "I think people have given up."

High-risk groups, as defined by the CDC, are people age 65 and older, adults and children with chronic diseases, babies 6 months to 23 months, pregnant women, nursing home residents, and people who live with children under 6 months of age.

Some state officials are expanding eligibility to younger people, those just over 50. The CDC is encouraging state officials to set their own guidelines based on local needs.

"They know what's best for their community," CDC spokesman Llelwyn Grant said. The federal agency is also working with state and local officials to redirect vaccine to areas where it's most needed for high-risk patients.

Health officials are worried about elderly and infirm people who don't live in nursing homes and who lack the resources to track down a flu shot.

"There are still some real desperate people out there," said Watson, of the Seattle medical company. "We just don't know how to find them."

It's still too soon to tell whether more people will get sick and die this year because of the vaccine shortage. Most years, the peak flu month is actually February, according to the CDC. Public health officials say the silver lining may be that the shortage focused more attention on simple, common-sense ways to stop the spread of the virus — washing your hands, staying home from school or work when you're sick, and avoiding touching your nose, eyes and mouth.

"At the turn of the 20th century, public health was all about teaching people not to spread disease," Selecky said. "Now at the turn of the 21st century, here we are again."