Bird flu vaccine shows good results in early trial

CHICAGO, Oct 5: An experimental vaccine for bird flu using new cell-based manufacturing methods showed promise at combating divergent strains of the virus in an early clinical trial, Baxter International Inc. has said.

The health-care products maker said yesterday preliminary results from a 270-patient study suggest the vaccine was safe, well-tolerated and may provide wider protection against H5N1 -- the bird flu virus -- for a larger number of people.

H5N1 mainly affects birds, but experts fear it could mutate into a strain easily transmitted from person to person, capable of killing millions of people in a global pandemic.

An H5N1 virus has killed at least 148 people since 2003, mostly in Indonesia, Vietnam, Thailand and China, according to the World Health Organization.

The results are the first data from any bird flu vaccine made using cell-based techniques, according to a Baxter spokeswoman Deb Spak.

The Deerfield, Illinois-based company is testing a new and better way for developing vaccines using cell-based manufacturing techniques that hold the promise of producing much larger quantities of vaccine in much less time.

Vaccine makers currently rely on egg-based production methods, which require steady supplies of carefully grown eggs and months of cultivation. The new method grows the vaccines in labs, in batches of cells called cell cultures.

Spak said the early-stage study suggests the vaccine could offer cross-protection from other strains of the virus.

''This is the first clinical demonstration that a candidate H5N1 (bird flu virus) vaccine can induce antibodies that neutralize widely divergent strains of H5N1,'' said Noel Barrett, vice president of global research and development for Baxter's vaccines business.

Barrett said the results must be confirmed with a larger study.

Baxter said the clinical trial of the experimental H5N1 vaccine in healthy adults in Austria and Singapore suggested the vaccine had similar side effects to those reported for seasonal flu vaccines.

LATE-STAGE CLINICAL TRIAL EARLY 2007

The preliminary results suggest the vaccine is highly capable of producing an immune response and can create antibodies to H5N1 even at the lowest dose level, the company said. A preliminary analysis of serum samples from study subjects showed the vaccine was able to neutralize the virus contained in the vaccine as well as other diverse strains of the H5N1 virus. Baxter plans to begin a late-stage clinical trial of the vaccine early next year and said it will present final results by the end of 2007.

Baxter's H5N1 vaccine candidate was produced using four different concentrations of antigen, the active ingredient. Two of the concentrations were with and without adjuvant, a substance added to vaccines to improve immune response.

Baxter and a number of other companies are working to develop a vaccine to protect against a potential bird flu pandemic. Europe's biggest drugmaker GlaxoSmithKline Plc in July said its egg-based vaccine could be mass produced in 2007.

French drugmaker Sanofi-Aventis and Swiss drugmaker Novartis are also working on a vaccine.

There is currently no vaccine against the bird flu virus, but for now it is treated with Tamiflu, also known as oseltamivir, an antiviral drug made by Swiss drugmaker Roche and U.S. biotechnology company Gilead Sciences Inc..

Glaxo also makes the inhaled drug Relenza under license from Australia's Biota, which also appears to treat both types of flu.

Reuters