Aug 27, 2004 (CIDRAP News) – Close to half of the nation’s influenza vaccine doses will be shipped later than expected this fall, but everyone who wants a flu shot should ultimately be able to get it, federal health officials said today.Chiron Corp. announced yesterday that it is delaying release of its flu vaccine doses until early October because some lots of vaccine didn’t meet sterility standards. The company said it expects to ship 46 million to 48 million doses, down from the 50 million doses predicted previously.But Julie Gerberding, MD, MPH, director of the Centers for Disease Control and Prevention (CDC), said today the CDC still expects that about 100 million doses of vaccine, more than ever before, will be available this year.”Those who are used to receiving their shot in early October may not get it then,” Gerberding said. But, “The bottom line is that right now we’re expecting to have enough flu vaccine so that everybody who needs flu vaccine can have it. . . . For folks who are trying to plan for their immunization, the best thing is to stay tuned to messages from your local health officers and your clinician.”The other flu vaccine manufacturers are expected to deliver their product on schedule, Gerberding reported. Chiron and Aventis Pasteur are each expected to produce roughly half of the projected 100 million doses, while MedImmune is likely to supply about 1.5 million doses of the intranasal vaccine FluMist, she said.Chiron anticipates shipping 40 million doses in October, and MedImmune also will deliver its doses in October, according to Gerberding. After shipping a few doses this month, Aventis anticipates delivering 15 million to 20 million doses in September and the rest in October, she said.”We’re confident that we’ll be able to get vaccination programs started on time with the doses that we do have,” Gerberding commented.Neither Chiron nor Gerberding revealed exactly what caused the problem with the Chiron vaccine, produced in Liverpool, England. The company announcement said “a small number of lots” failed to meet sterility specifications. “While ongoing internal investigations into the root cause of the variance indicate no widespread issues with the manufacturing process, Chiron has delayed releasing any Fluvirin doses until it has completed additional release tests,” the announcement said.Gerberding said Chiron officials told her they “have identified the problem, they’re fixing it, and they’re taking extra steps to make sure they have a safe product before they ship it.”Chiron said its planned “late-season delivery” of 2 million Fluvirin doses for the CDC stockpile for the Vaccines for Children program remains on schedule. Those doses are in addition to the 46 million to 48 million produced for general distribution.Gerberding said the vaccine lots affected by the sterility problem don’t include any pediatric vaccine. “We’re not expecting a decrease in total predicted doses available for children at this time,” she said.In response to a question, she said Chiron’s vaccine production problems, to her knowledge, were not related to thimerosal, a mercury compound used as a preservative in most flu vaccine doses. The CDC predicted in May that 6 million to 8 million doses of thimerosal-free flu vaccine would be produced this year for people concerned about the preservative.Gerberding said flu vaccine delays are nothing new. “As recently as 2001 we had some shipments that were delayed until October. . . . We’ve been here before, we’ve done this before, and we’ve handled it.”The CDC, she noted, recommends flu vaccination for people aged 50 and older, those who have a chronic medical condition or weakened immunity, those who expect to be pregnant during the flu season, children aged 6 to 23 months, healthcare workers, and people in close contact with others in the foregoing categories.