Influenza Virus Vaccine Live Intranasal (Aviron)

Aviron has signed a Collaborative Research and Development Agreement with the US National Institute of Allergy and Infectious Diseases, and a licensing agreement with the University of Michigan, Ann Arbor, USA, to complete the development of a cold-adapted live influenza virus vaccine (FluMist^TM) that can be administered by nasal spray.

Aviron submitted its first product licence application to the US Food and Drug Administration (FDA) for FluMist^TM in 1998, and will submit a biologics licence application in 1999. Preliminary results of a bridging study indicated that the lot of FluMist^TM blended and filled at Packaging Coordinators, Inc. in Philadelphia had similar immunogenicity and tolerability for all 3 1997-1998 influenza strains as the vaccine used in earlier clinical trials which was manufactured by Medeva in the UK. The company is seeking US licensure for FluMist^TM to prevent influenza and its complications in children and adults, and for coadministration with the inactivated flu vaccine in the elderly.

The vaccine consists of a recombinant attenuated live virus (A/Ann Arbor/6/60 or B/Ann Arbor/1/66) expressing haemagglutinin from 1 or more virulent influenza strains. It triggers stronger, more long-lasting local immune protection than the conventional killed virus vaccine. The vaccine is termed cold-adapted because the virus has been adapted to proliferate and trigger antibodies in the nasal passages, which are below normal body temperature. The cold-adapted live influenza vaccine has been widely evaluated in the US and Japan since 1975, in clinical trials involving more than 7000 people. Aviron has completed phase II clinical trials in adults in the US and phase III trials in US children aged 15 to 71 months. Additional phase III trials in adults and elderly are ongoing. Aviron has also commenced phase III trials to test the safety of its intranasal live vaccine in children with moderate to severe asthma.

The vaccine will be delivered using a novel spray syringe which releases a large particle aerosol spray (the AccuSpray nasal delivery system by Becton Dickinson).

Aviron holds exclusive worldwide rights to the vaccine except for Japan, where Kaketsuken Pharmaceuticals is the licensee. Sang-A will manufacture and market Aviron's influenza vaccine in Korea. Medeva Pharma (formerly Evans Medical) are to manufacture the components of FluMist^TM in the UK. Packaging Coordinators, Inc. (Cardinal subsidiary) will carry out secondary manufacturing of the vaccine in the US. CSL Ltd of Australia will collaborate on the development, sale and distribution of Aviron's vaccine in the South Pacific. Aviron has also entered into an agreement with Wyeth-Lederle for worldwide collaboration in the marketing of Flu-Mist^TM, excluding Korea, Australia, New Zealand and certain South Pacific countries.

FluMist^TM, a live attenuated influenza virus vaccine, offers significant advantages over currently marketed influenza vaccines consisting of inactivated viruses. Unlike these vaccines, it triggers mucosal immune responses in addition to systemic responses, stimulating stronger, longer-lasting immune protection. In addition, the intranasal administration of FluMist^TM is more convenient and tolerable for recipients than the injections required with current influenza vaccines.