Not so good, so far

Sanofi-Aventis Aims to Fix Bird-Flu Vaccine, Now 53% Effective

March 30 (Bloomberg) -- Sanofi-Aventis SA said improving its bird-flu vaccine is a priority after a study found an early version of the product was only about 50 percent effective.

The U.S. Department of Health and Human Services has spent $250 million to date on avian-flu vaccine, mostly from Sanofi, HHS spokesman William Hall said in an interview yesterday. The agency is hoping to stockpile enough vaccine for 20 million people. The new study results released yesterday means the supply of vaccine ordered by the U.S. will protect only about 4 million people, Hall said

At the dose that worked best in the study, the vaccine triggered a protective immune response in 53 percent of test subjects, researchers reported in today's issue of the New England Journal of Medicine released late yesterday.

Improving the vaccine is ``a top priority for our company,'' said Len Lavenda, a spokesman at Sanofi's vaccine unit in Swiftwater, Pennsylvania. ``We want to protect as many people as possible, as soon as possible. To conclude that this result is as good as it gets would be premature, at least.'' He said Sanofi, based in Paris, is also planning to add production capacity.

At least 186 confirmed cases of H5N1 avian flu have occurred in humans since late 2003, and 105 persons died, said the World Health Organization. Most victims evidently had contact with infected birds or their blood or excrement.

Confirmed Cases

The amount of vaccine needed to protect about half of recipients in the study was so high that existing labs worldwide could produce only enough to supply about 1.3 percent of the world's population, wrote Gregory Poland, 50, head of the vaccine research group at the Mayo Clinic College of Medicine in Rochester, Minnesota, in a journal commentary.

As a result, Poland wrote, the effectiveness of the vaccine was ``poor to moderate at best,''

The vaccine studied, which was based on a virus collected in Vietnam in 2004, didn't cause any ``severe'' side effects, the study said. All of the subjects have been given a third dose whose effect isn't known yet, said researcher John Treanor, 51, an infectious-diseases physician at the University of Rochester in upstate New York.