The World Health Organization is urging drugmakers including GlaxoSmithKline Plc, Sanofi-Aventis SA and Chiron Corp. to join in developing a vaccine to stop Asia´s deadly bird flu virus from triggering a pandemic.

Klaus Stoehr, director of the UN agency´s global influenza program, will meet in Geneva today and tomorrow with representatives of the world´s major vaccine producers to enlist them in readying hundreds of millions of doses of vaccine in case the deadly strain of influenza starts spreading among humans.

Pandemics, such as the 1918-1919 flu outbreak that killed as many as 50 million people, have struck three times in the 20th century and the WHO says the bird flu virus has makings of another. Developing the vaccine may cost the companies a combined $50 million, says ex-Sanofi vaccine executive David Fedson.

``We don´t have a pandemic and we might not have one so you can understand that vaccine manufacturers might be reluctant to invest in a new vaccine that no one would ever use,´´ Dick Thompson, a spokesman at the WHO, said in an interview. ``What we want to do is somehow find ways to encourage development.´´

Only two companies, Paris-based Sanofi-Aventis and Emeryville, California-based Chiron, have so far accepted WHO´s offer of vaccine ``seed stock´´ to start production.

The request comes as the world´s vaccine manufacturing capacity is strained after contamination forced the shutdown of a Chiron plant in Liverpool, England, that was to produce 50 million doses of a different flu vaccine for the U.S. market.

`Very Scary´

The H5N1 bird flu strain, spreading now in Asia, has killed 32 people in Thailand and Vietnam. More than 100 million poultry have been killed to stop the flu, and the virus is now spreading in ducks, which can excrete the germs widely into drinking water. The more often humans are exposed, the greater the chance a mutation will occur like the one that set off the 1918 epidemic.

``It´s certainly very scary,´´ said Malik Peiris, a University of Hong Kong virologist, in an interview in Washington. ``One can be sure it would make SARS look like a picnic.´´ Severe acute respiratory syndrome sped around the world carried by infected airline travelers.

A human vaccine against the bird flu theoretically could be designed and approved in about six months, and companies could mass- produce it when needed, Stoehr said in an interview.

In reality, intellectual property rights, questions about the most effective form for a vaccine and legal restrictions on genetically modified organisms may delay production at a critical time, said Stoehr, the director of the WHO´s global influenza program.

`Collective Approach´

``What we need is public health leadership on an international level,´´ said Fedson, now a consultant to vaccine manufacturers, in a telephone interview. ``If the highest officials are there showing the importance and urgency of a collective approach to pandemic supply issues, it´s a good beginning.´´

The world´s capacity for a flu vaccine is currently about 300 million doses annually, Stoehr said. Global population is about 6.4 billion, according to the U.S. Central Intelligence Agency.

The U.S. National Institutes of Health has given Sanofi- Aventis and Chiron, the world´s second-biggest maker of flu vaccines, contracts to produce a prototype bird flu vaccine, expected to be ready this year.

``Obviously this is something we would look at seriously,´´ said Chiron spokesman John Gallagher last week when asked about the WHO meeting.

Who Owns It?

Flu vaccine production begins with a ``seed virus´´ that grows in chicken eggs, making proteins that will stimulate the immune system to prepare for an infection. Research groups at St. Jude Children´s Research Hospital in Memphis, Tennessee, and the U.K. National Institute of Biological Standards and Control used a technique called ``reverse genetics´´ to make a seed virus for a bird flu vaccine.

Intellectual property rights to reverse genetics technology are held by four groups in the U.S.: Gaithersburg, Maryland-based flu vaccine maker MedImmune Inc., Mt. Sinai Hospital in New York, St. Jude Hospital, and the University of Wisconsin.

Brentford, England-based Glaxo, Europe´s biggest drugmaker, and others have turned down the U.K.-made seed virus because it isn´t clear who owns the rights to reverse genetics, or how much companies might have to pay for them, said Norbert Hehme, general manager of Glaxo´s biological plant in Dresden, Germany.

Clarification, Please

``We need to get some clarification on these IP rights,´´ he said in a telephone interview. ``From the industry side it´s hard to deal with.´´ The seed virus is considered a genetically modified organism and must be cleared by state and local governments where it would be used, Hehme said.

MedImmune will waive royalties on its intellectual property for pandemic flu vaccines that are offered free to the public, the company said in a statement.

Companies will also be asked to pay for human tests of the vaccine and obtain regulatory approval in countries where it would be sold, Stoehr said. The WHO will ask regulators whether companies can pool data from their experiments to keep the cost of testing down, he said.