U.S. Health and Human Services Secretary Tommy Thompson (search) said Monday that enough flu vaccine (search) will be available for most people who need it and told seniors to stop standing in long lines to get a shot.

"We want people to relax," Thompson said at a news conference. "The flu season is not here."

Seniors around the country have been standing in lines at shopping plazas to get flu shots since news of a shortage surfaced this month. British regulators shut down shipments from Chiron Corp. (search), which had made millions of flu shots earmarked for the U.S. market. The shutdown cut the U.S. supply of flu shots almost in half.

Thompson said the flu vaccine supply will be reallocated to parts of the country where it is needed most. Seniors and very young children are most at risk for severe complications from the flu.

"We are looking all over the regions to find out where there is a shortage, and we will redeploy the resources to make sure the seniors get the vaccine first," he said. He noted that 91 percent of flu deaths last year were people 65 or older.

Thompson advised people to first seek the shot from their doctor or a clinic. If that fails, they should contact the CDC in Atlanta, he said.

Dr. Julie Gerberding, director of the federal Centers for Disease Control and Prevention, said on ABC's "Good Morning America" that only a few cases of flu have been reported this season, and that 20 million doses would soon be available for seniors.

"We are reassuring people that vaccine is on the way," she said.

Last week, however, Gerberding had said it was unlikely all high-risk people who want a flu shot would be able find one.

In Atlanta on Monday, Dr. Mitchell Cohen, director of the CDC's coordinating center for infectious diseases, said the current vaccine "will be distributed over a six- to seven-week period, so we have some opportunity to identify those areas" that need supplies "over the next week or so."

He said his staff was continuing to compile supply reports from each state but declined to name places that were low on flu shots. El Paso, Texas, reported late last week it ran out of vaccine; the township of Bloomfield, N.J., created a lottery to distribute 300 remaining shots.

In San Francisco on Monday, a group representing the nation's emergency room doctors called on Thompson to convene a "crisis summit" of federal agencies and health professionals to plan guidelines in case of a possible flu epidemic.

"We believe our nation faces the potential for a public health disaster this flu season," said Dr. Arthur Kellerman, a member of the board of the American College of Emergency Physicians, which was holding its annual meeting.

"The combination of the vaccine shortage, more than 80 million Americans at high risk of flu complications, and a nationwide emergency department crowding crisis means American's emergency physicians and nurses are faced with the prospect of the 'perfect storm' — a surge of critically ill flu patients and no resources to care for them," said Kellerman, who also chairs Emory University's Department of Emergency Medicine.

Thompson said the number of manufacturers must be increased. For that to happen, Congress must remove liability for vaccine makers and the government must commit to buying millions of doses every year so the producers are assured of a "ready market," he said.

Thompson said there are still 20 million doses for seniors and 4 million doses for children that are being shipped out at a rate of about 3 million per week.