Washington Editor
WASHINGTON - The FDA signed off on this year's influenza vaccines, which are being made in a formulation recommended by both the World Health Organization and agency's own advisory committee.
The product includes one viral strain that was used in last year's vaccine and two new strains. The three have been judged as most likely to cause flu in the Northern Hemisphere this season.
Collectively, four vaccine manufacturers plan to produce an aggregate of about 100 million doses for the U.S. market. Each year, the quartet of vaccine makers submit to the FDA information and samples of their virus strains being manufactured for the upcoming flu season.
Among the flu vaccines is FluMist (influenza virus vaccine live, intranasal), from MedImmune Inc. The Gaithersburg, Md.-based company began shipping the product last month and expects to have all lots of FluMist approved and released for commercial sale by the middle of next month.
MedImmune spokeswoman Clarencia Stephen told BioWorld Today that that the company plans to produce 3 million doses this season, a total in line with its production in past years. This marks the fourth season that FluMist will be on the market. Its bulk material is produced in the UK, and the product's manufacturing is finished domestically.
In addition, there are three injectable vaccines: Fluvirin from Chiron Vaccines Ltd., part of Novartis AG in Basel, Switzerland; Fluarix from GlaxoSmithKline Biologicals, part of GlaxoSmithKline plc in London; and Fluzone from Sanofi Pasteur Inc., part of Sanofi-Aventis Group in Lyon, France.
Of note, Fluzone has encountered a manufacturing difficulty this year. There were sterility failures for monovalent concentrates of the product, as well as problems with good manufacturing practices for finished products. However, the FDA has indicated that the manufacturing hiccup is not expected to significantly affect the availability of Fluzone, which is produced in Swiftwater, Pa. (See BioWorld Today, July 6, 2006.)
That was not the case two years ago for Chiron's Fluvirin, which was not delivered because of different sterility problems at its manufacturing facility in Liverpool, UK. That led the FDA to temporarily shutter that site, and led to a significant shortage of flu vaccine in the U.S. (See BioWorld Today, Oct. 6, 2004.)
GlaxoSmithKline's Fluarix also is produced overseas.
According to the Centers for Disease Control and Prevention in Atlanta, on average 5 percent to 20 percent of the U.S. population gets the flu every year, more than 200,000 people are hospitalized from its complications and about 36,000 people die as a result. Those at high risk for serious complications include the elderly, children and people with certain chronic medical conditions.
A new formulation of FluMist, CAIV-T (cold adapted influenza vaccine, trivalent), remains under FDA review following the agency's recent complete response letter requesting more information on already submitted data. A refrigerator-stable version of the intranasal vaccine, it does not require frozen storage like FluMist, offering a more convenient option. MedImmune filed for approval to use CAIV-T in people ages 5 to 49. (See BioWorld Today, July 19, 2006.)
More recently, the company filed for CAIV-T's approval in younger children. But CAIV-T remains on next year's horizon, at the earliest, as it could be available in the 2007-2008 season. Once approved, MedImmune hopes it would gain traction more quickly than FluMist, which stumbled out of the gate and has never made much of an impact on the company's bottom line. Last year, its sales totaled $21 million.
Because different flu virus strains might appear each year, one or more of the strains in the vaccine may need to be changed to protect against what public health officials expect to most likely infect people.
Seasonal flu vaccines do not protect against avian flu, which is caused by different viral strains, but all four U.S.-licensed flu vaccine manufacturers are among companies involved in efforts to create a bird flu vaccine.
