FDA approves refrigerated form of FluMist

Jan 9, 2007 (CIDRAP News) – The US Food and Drug Administration (FDA) has approved a refrigerated form of FluMist, the nasal-spray influenza vaccine, which should be more convenient for providers than the current formulation, MedImmune Inc. announced yesterday.

FluMist, a live attenuated vaccine first approved in 2003, is currently approved for use in healthy children and adults from ages 5 to 49 years.

The new formulation will allow healthcare providers to store the vaccine in a refrigerator rather than a freezer as now required, said Frank M. Malinoski, MD, PhD, senior vice president of medical and scientific affairs at MedImmune, based in Gaithersburg, Md.

"We recognize that the frozen storage presented difficulties for some physician practices as well as for providers who administer vaccine in places like schools, pharmacies, and grocery stores, and we are confident that this improvement will enhance access to this important vaccine," he said in a news release.

The new FluMist formulation, known in clinical studies as cold adapted influenza vaccine trivalent (CAIV-T), will be available for the 2007-08 flu season. MedImmune said the frozen and refrigerated formulations are free of preservatives, including thimerosal.

In July 2006 MedImmune asked the FDA to expand the age indication for the vaccine to children as young as 1 year who do not have a history of wheezing or asthma. If the FDA approves the request, MedImmune said, production of CAIV-T would be increased for the 2007-08 season. The company said it hopes to ship its first doses in time for physicians to begin vaccinating patients as early as August.

Phase 3 trial results that MedImmune submitted to the FDA in 2006 showed that FluMist was 55% more effective than an injectable vaccine in children aged 6 months to about 5 years, according to the MedImmune release. FluMist was more effective against flu viruses both well-matched and poorly matched to the vaccine in the 2004-05 flu season.

However, a study in the Dec 14, 2006, issue of the New England Journal of Medicine suggested that in adults, FluMist was less effective against type B influenza than the injected vaccine in the 2004-05 season. Both vaccines had similar efficacy against influenza A in adults.

See also:

Jan 8 MedImmune press release

May 17 CIDRAP News story "Study: FluMist works better than shots in kids under 5"

Ohmit SE, Victor JC, Rotthoff JR, et al. Prevention of antigenically drifted influenza by inactivated and live attenuated vaccines. N Engl J Med 2006;355(24):2513-22 [Full text]

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