U.S. health officials broadened national flu vaccination recommendations Monday while acknowledging that fears of a potential bird flu pandemic have complicated their efforts.

The government issued a planned expansion of its flu shot recommendations about a month after first restricting shots to high-risk people because of uncertainties over vaccine supplies. Now everyone is being encouraged to get shots to protect against seasonal flu, which kills an average of 36,000 people and causes about 200,000 hospitalizations in the U.S. each year, according to the CDC.

Last year’s flu season was fraught with confusion and vaccine shortages after British regulators shut down the manufacturing plant of Chiron Corp. because of safety problems. The move effectively denied the U.S. about half its expected vaccine supply.

Vaccine Supply Will Meet Demand

Public health officials this year at first restricted flu shots to the elderly, infants, people with chronic illnesses, and health workers in an effort to prioritize patients at high risk for flu complications. On Monday flu shot recommendations were expanded to include everyone as officials estimated that manufacturers would be able to meet vaccine demand.

Vaccine makers now expect to produce at least 71 million flu shots for the 2005-2006 season. Chiron is expected to produce less than the 18 million to 26 million doses it had originally projected for this year.

“There is no reason for anyone to delay or to go without their annual flu shot,” Health and Human Services Secretary Michael O. Leavitt told reporters.

Still, clinics and doctors offices have reported some delays in receiving promised vaccines from manufacturers, frustrating early efforts by some patients to get vaccinated.

Leavitt called the reports “anecdotal” but emphasized them in encouraging patients to be persistent in seeking flu shots. “We anticipate that the suppliers will be responding to their customers in regular order,” he said.

Bird Flu Concerns

The 2005-2006 flu season begins as the threat of a possible bird flu pandemic continues to garner widespread media coverage. Officials acknowledged that they are now combating an erroneous perception that flu shots in clinics now offer protection against bird flu.

“It is difficult for some people to understand the difference between seasonal flu and pandemic flu. They just hear flu,” said CDC director Julie M. Gerberding, MD.

Seasonal flu vaccine offers protection against three common flu virus strains, but the bird flu virus, dubbed H5N1, is not one of them. Sanofi-Pasteur has signed a deal to begin early production of a still-experimental H5N1 vaccine that government officials intend to stockpile for use in the event of a pandemic.

The federal government has also ordered close to 18 million treatment courses of Roche’s Tamiflu antiviral drug as a possible hedge against a bird flu outbreak. Orders from multiple governments have caused a shortage of the drug and political pressure for Roche to license its manufacture by generic pharmaceutical firms.

The company announced last week that it was entering talks with four companies over possible sublicensing deals.

By Todd Zwillich, reviewed by Louise Chang, MD

SOURCES: Michael O. Leavitt, secretary, Department of Health and Human Services. Julie M. Gerberding, MD, director, CDC. CDC web site.