Americans’ supply of flu vaccine was abruptly cut in half Tuesday, prompting the government to ask most healthy adults to delay or skip flu shots so the very young, the elderly and others most at risk from influenza can get scarce supplies.

“The news today means not all residents of the county will qualify for the flu shot,” said Kay Kent, director of the Lawrence-Douglas County Health Department.

British regulators unexpectedly shut down a major flu-shot supplier Tuesday, prompting a record U.S. shortage just as flu season is about to begin.

The change in course comes as the U.S. Centers for Disease Control and Prevention expanded the target population for flu shots and was in the midst of a campaign urging more people than ever to get them.

Before the announcement, this season’s supply was supposed to be about 100 million doses, up from 87 million last winter.

In Douglas County, health officials had ordered 6,800 vaccine doses for the flu season, Kent said, but has received only 1,600.

“At this time, we’re not anticipating there would be additional vaccine,” Kent said.

Douglas County health officials learned about the vaccine shortage during a late-afternoon conference call with the CDC.

The news cast uncertainty on plans for a mass vaccination planned for Oct. 23 at Free State High School, part of the “Flu-X” exercise to test the county’s bioterrorism response. Officials had hoped to vaccinate 3,300 people that day. Now they’re not sure what will happen.

“We should know that in the next 24, 48 hours,” Kent said.

6News video: Flu vaccine supplier stopped short

The license of Chiron Corp. was suspended for three months, citing manufacturing problems at the Liverpool, England, factory where the company makes its leading Fluvirin flu vaccine.

The sanction means more than a delay, Chiron officials said: The company will ship no Fluvirin anywhere this year, including the 46 million to 48 million doses originally planned for the United States.

The rest of the U.S. flu shot supply — the 54 million doses — is coming from a different manufacturer, Aventis Pasteur, which already has begun shipping.

Most adults excluded

The CDC immediately convened a telephone meeting of a committee of experts that advises it on vaccine policy. By mid-afternoon the panel had drawn up a list of groups that should get first claim on the 54 million doses expected to be available. The list excludes nearly all healthy adults.

The Bush administration urged the public and doctors to begin voluntary rationing of the roughly 54 million flu shots that will be available this year.

Kent said vaccine would be reserved for babies and toddlers ages 6-23 months; people 65 or older; anyone with a chronic condition such as heart or lung disease; pregnant women; nursing home residents; children on aspirin therapy; health care workers who care for high-risk groups; and anyone who cares for or lives with babies younger than 6 months.

For everyone else, “take a deep breath. This is not an emergency,” said Dr. Julie Gerberding, head of the CDC. “We don’t want people to rush out and look for a vaccine today.”

Other options

High-risk patients depend on flu shots because the injections are made of killed influenza virus. Other people have another option: About 1 million doses of an inhaled flu vaccine, MedImmune Inc.’s FluMist, will be available for healthy 5- to 49-year-olds. It’s made from live but weakened influenza virus.

A flu treatment called Tamiflu also can protect against infection if swallowed daily during an outbreak. Manufacturer Roche Pharmaceuticals said it would step up production in anticipation of greater demand this winter.

Flu shot campaigns usually start in October, a month before the flu season typically begins in the United States. In an average year, flu kills 36,000 people and hospitalizes another 114,000, mostly the elderly.

— Journal-World wire services contributed to this report.