Salvage of Chiron flu vaccine unlikely

Oct 9, 2004 (CIDRAP News) – Lester Crawford, acting director of the US Food and Drug Administration (FDA), appearing before the House Committee on Government Reform yesterday, said he was pessimistic about the possiblility that any of the 48 million doses of influenza vaccine expected in the United States from Chiron Corp. can be salvaged for use this flu season, according to new service reports. FDA experts remain in England this weekend to make the final determination, with visits planned to the Liverpool plant whose manufacturing license was revoked earlier in the week, effectively cancelling half the US's supply.

Several lots of Chiron's vaccine, Fluvirin, were found to be contaminated, leading to suspension of Chiron's manufacturing license by Britain's Medicines and Healthcare Products Regulatory Agency (MHRA). It came out this week that the organism implicated in the contamination is Serratia, a bacterium that lives in water, soil, plants, and animals and is not dangerous if encountered on environmental surfaces.

When Serratia is harbored in medical equipment, however, it can cause illness and has been documented in numerous outbreaks (see link below for example of bronchoscope contamination). In commenting on the Chiron situation, Dr. Robert Belshe, director of the division of infectious diseases and immunology at St. Louis University, conjectured that it may have come from bottles, vials, or rubber stoppers, according to a Wall Street Journal story.

Aventis Pasteur, the other large supplier of inactived flu vaccine for the United States, has said it will be able to supply 55.4 million doses of its Fluzone, according to an Associated Press story. This is somewhat more than it had originally commited to, but doses beyond that cannot be made in time for this year's flu season.

MedImmune, makers of FluMist, an inhalable form of flu vaccine, was asked by the Center for Disease Control and Prevention to provide more than the 1.5 million doses promised. The company has said it can provide nearly 1 million extra doses by late November, according to the Associated Press. The doses will come from already-produced frozen bulk vaccine.

FluMist is FDA-approved for use only in people aged 5 to 49, which is the group least in need of vaccination. Four million doses were produced for the 2003-2004 flu season but much of that supply went unused, partly because of its higher cost in comparison with injected vaccines. MedImmune has cut the cost of FluMist this year and is also working on a new formulation it expects to be available in 2007.

Public health officials are working quickly to track down the doses of vaccine that are already in the hands of distributors and providers to ascertain how the unexpectedly limited supply can best be made available to the populations most in need of vaccinations (see link below to interim guidelines).

See also:

2003 New England Journal of Medicine article on Serratia contamination of brochoscopes [Abstract]

CDC interim recommendations for flu vaccine
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5339a6.htm

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