Why are flu shots delayed in the United States -- but not elsewhere?

Slow-growing virus cultures and production troubles at two U.S. drug companies contributed to delivery delays of vaccines in the United States

ATLANTA, Georgia (CNN) -- With flu season just around the corner, doctors across the world are opening their doors to patients who hope to protect themselves from influenza.

In Israel, for example, flu shots became available weeks ago -- the same goes for Germany and many other parts of Europe.

But in the Unites States, doctors say most clinics aren't expected to start giving out flu vaccinations until sometime in November.

Why? Manufacturing problems created a delay in delivery of this year's flu vaccine, prompting the Centers for Disease Control and Prevention in Atlanta to call upon health care providers to prioritize their patients.

"We're urging through the month of November that health care providers focus first on immunizing the elderly, the chronically ill and women who will be in their second or third trimester of pregnancy during the flu season," U.S. Surgeon General David Satcher said this week. "Those (are the) groups who are most at risk."

Each year in the United States, flu sends more than 100,000 people to the hospital and is responsible for at least 20,000 deaths, according to national health experts.

Government officials can count themselves as partly to blame for this year's delay in protecting the public against the flu. The U.S. Food and Drug Administration shut down vaccine manufacturing at Parkedale Pharmaceuticals in Rochester, Michigan, following reports of safety violations. Parkedale was one of four companies making the vaccine in the United States.

Large bottles like these are used to grow influenza and produce its vaccine

The FDA also issued citations against another flu shot maker -- Wyeth-Ayerst of Philadelphia, Pennsylvania. According to a company spokesman, Wyeth-Ayerst got a late start in production due to time lost correcting the problems.

Wyeth-Ayerst's problems stemmed from manufacturing protocol, not safety issues, the FDA said.

Another reason for the delivery delay is that vaccine makers across the world discovered this year's flu strain grew very slow.

One U.S. maker, Aventis Pasteur, said Europeans had space in the factory to compensate for the slow-growing influenza strain -- but American producers did not.

"The only way we can increase the number of doses is to increase the number of days in our program," said Aventis' Jim Robinson. "When we do that, it means the doses come out later in the year."

The vaccination delays have put doctors in the unwelcome position of having to tell some patients 'no.'

"The healthy individuals are just going to have to wait their turn," said Dr. Sandra Fryhofer, president of the American College of Physicians.

So what does all this mean for would-be flu sufferers? It partly depends on when flu season hits. Once a flu shot is given, it takes about two weeks for it to become effective.

Still, top doctors in the United States are confident that all patients who desire flu vaccinations should be able to receive them -- even if it means giving the vaccinations into the first months of next year.

Specific predictions of flu season virulence are difficult, experts say, but experience is some guide. And 14 out of the past 18 flu seasons have not peaked until January -- which could make a late-starting vaccination campaign less effective.

"We're not denying that we have a problem," Satcher said this week. "We'd love to immunize as many people as possible as early as possible. But we don't expect the delay to have a major impact on the epidemic."

Surgeon General: High-risk patients get first flu shots
October 25, 2000
Some experts predict flu season could be grim
October 24, 2000

National Institutes of Health
Centers for Disease Control in Atlanta
FDA letter to Parkedale Pharmaceuticals

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