SAN FRANCISCO – U.S. health officials said they do not expect a flu shot shortage after a leading flu vaccine maker warned that it would hold up millions of doses because several batches were contaminated.
Only about 4 million doses appear to be tainted -- not enough to have a big impact on this year's supply although there may be a delay in making some shots available, officials said Friday.
"This is not a crisis," said Dr. Julie Gerberding, director of the Centers for Disease Control (search) and Prevention.
"We'll end up having more vaccine doses than we've ever had before. Ultimately, all people who need flu vaccine should be able to get their shots," she said.
On Thursday, Chiron Corp. (search), which supply's half the nation's flu vaccine, said factory tests had revealed that some batches were tainted, and that all 50 million doses that the company was producing would be held up for additional tests to ensure safety.
"We are confident that we've identified the root cause," said John Vavricka, Chiron's vice president of commercial operations for North America. He refused to say what the contaminant was.
He said that all but 4 million doses had proven pure in testing, but 50 million doses will be retested, causing a delay.
Chiron still plans to ship 46 million to 48 million doses by early October, about a month later than usual, plus 2 million more for the federal government's emergency stockpile, he said.
The stockpile is new this year and will contain 4.5 million doses, Gerberding said.
Meanwhile, the nation's other big producer, Aventis Pasteur (search), reported that federal officials had asked it to make additional vaccine to cover any shortfalls. But the company is already at capacity and can't produce more until after November when existing orders are filled.
Aventis expects to ship 52 million doses -- 9 million more than last year.
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.
Last year, the season started early, producing record demand for vaccine and temporary shortages. In the end, some vaccine was leftover, and the season was no worse than usual. The previous two years saw vaccine shortages for different reasons.
This year, health officials expect demand for vaccine to be strong because of memories of shortages and worries about new flu strains circulating.
The vaccine contamination news has them worried about two scenarios: that people will seek shots...and that they won't.
"We're walking a fine line here," Gerberding said. "What we don't want is for people to race out and stand at the head of the line" in early October, worried about shortages, and conversely, that people who need a shot will avoid getting one because of safety fears, she said.
No tainted vaccine has reached the public, officials emphasized. About 1 million doses have already been shipped, but Chiron said the vaccine remains its property even though it has been sent to distributors.
In fact, the whole episode shows the safety of the process because Chiron found the problem before vaccine was released and reported it right away, said Len Lavenda, spokesman for competitor Aventis.
"The system worked," he said.
Meanwhile, the Brazilian government stopped distribution of a vaccine manufactured by Chiron, an Italian company, after 120 patients reported allergic reactions, health officials said Wednesday. The vaccine against mumps, measles and rubella provoked five cases of anaphylactic shock and 115 lesser allergic reactions in children in seven states.
Brazil's health ministry pulled 5.7 million doses from a national campaign that has vaccinated 1.6 million children since Saturday. The vaccine was replaced by a locally produced equivalent.
Flu shots are recommended for people 50 and older, children and adults with a chronic health problem or weak immune system, health care workers, people who live with or take care of people at risk of flu complications, and -- for the first time this year -- children ages 6 to 23 months.
Any shortage that develops could be a boon for FluMist, the new inhaled flu vaccine approved last year for use in healthy 5- to 49-year-olds. It's made from modified live virus and isn't considered safe for the elderly or people with medical problems.
Last year, its maker, Medimmune, produced 4 million to 5 million doses but sold only 450,000. Drawbacks include storage and distribution difficulties -- the vaccine must be kept frozen -- and cost: FluMist sells for about $53, triple the price of flu shots.
Medimmune plans to supply about 1.5 million doses this year and can't expand, said spokeswoman Jamie Lacey.
"You're kind of locked in several months back in terms of what you can manufacture," she said.