The federal government will provide funding in Wednesday´s budget to develop trial batches of a vaccine against the avian flu virus feared by many to be poised to spark a deadly influenza pandemic, The Canadian Press has learned.

Funding for the H5N1 vaccine project is part of a larger pocket of roughly $50 million that will be used to advance Canada´s pandemic influenza preparedness effort, government sources said. The money will be in addition to the $24 million the federal government recently invested in stockpiling 960,000 treatment courses of oseltamivir, an anti-viral drug.

Testing and licensing trial batches of H5N1 vaccine would slash four months off the production schedule should a pandemic with this virus occur, officials of the Public Health Agency of Canada and Health Canada´s vaccine regulatory arm have said in the past in advocating for the trials.

The vaccine will be made by Canada´s pandemic influenza vaccine manufacturer, ID Biomedical, at its plant outside Quebec City. The company has said it would cost roughly $20 million for it to produce the vaccine.

Announcement of the decision to fund the project comes hard on the heels of a declaration by the director of the U.S. Centers for Disease Control that the H5N1 virus constitutes the single greatest threat to the world at present.

"This is a very ominous situation for the globe," Dr. Julie Gerberding said at a scientific meeting in Washington, D.C., on Monday.

The decision to fund H5N1 vaccine trials was welcomed by the World Health Organization, which has been urging countries and vaccine makers to conduct trials aimed at learning as much about the effective use of an H5N1 vaccine as possible, including how many doses would be needed to induce immune protection and how large they would have to be.

"Things are moving," Dr. Klaus Stohr said from Geneva.

There is currently no scientific data on how to effectively use an H5N1 vaccine, although a number of countries have either commissioned similar research or are on the verge of doing so. The leader is the United States, which will, within weeks, begin clinical trials using 8,000 doses of vaccine produced by Aventis-Pasteur (now Sanofi-Pasteur).

But flu experts will be watching Canada´s program because it could answer key questions the early stages of the U.S. research will not.

The public health agency´s plan includes trying to determine how to stretch what will be limited vaccine supplies by the addition of chemical additives called adjuvants that boost the immune response a vaccine produces. Such an approach is called an antigen sparing strategy.

"The results obtained in Canada will be of significance globally," Stohr said.

Flu vaccine expert Dr. David Fedson agreed, saying it is crucial that Canada and other countries with flu vaccine manufacturers within their borders fund research aimed at finding ways to make vaccine available to as many of the world´s people as possible.

"This is essential because pandemic vaccines will be needed by millions of people who live in countries without vaccine companies," said Fedson, a retired Aventis-Pasteur executive. "And these countries will never get any vaccine unless an antigen-sparing formulation can be provided."

Proponents within Canada´s public health agency have urged the government to fund clinical trials so that ID Biomedical can gain experience working with the virus, work out any bugs in the production process, as well as test and license an H5N1 vaccine.

Once an H5N1 vaccine has gone through the regulatory process, future versions - even with a slightly different variant of the virus - can piggyback off that licence, significantly speeding up how long it will take to make vaccine available to Canadians once a pandemic starts.

In order to produce vaccine for the highly lethal virus, ID Biomedical must build what amounts to a high-biocontainment plant within its existing plant, which accounts for the bulk of the $20 million cost.

Building and certifying that facility will take about 10 months, company officials have said. They expect to be able to deliver several thousand doses of H5N1 vaccine to the public health agency for testing within about a year.