LONDON, Oct 26 (Reuters) - GlaxoSmithKline Plc <GSK.L> expects to sign more contracts to supply governments with its experimental bird flu vaccine for humans, following purchases by Switzerland and an unidentified Asian country. "Between now and Christmas, I expect we will sign a few more in Europe and elsewhere," Chief Executive Jean-Pierre Garnier told analysts in a post-results conference call. Europe's biggest drugmaker announced earlier this month that the Swiss Federal Office of Public Health had ordered 8 million doses of its H5N1 vaccine to protect its entire population in the event of an influenza pandemic, which many experts fear may be triggered by bird flu. The vaccine has not yet won regulatory approval but Glaxo plans to file it with the European Medicines Agency by the end of 2006. Glaxo's vaccine uses only a very low dose of active ingredient, which should help to stretch scarce supplies. A key challenge in the race to produce a vaccine for millions of people around the world -- which governments are keen to stockpile -- is how to make the maximum number of shots from the minimum amount of antigen, or active ingredient. While Glaxo's vaccine offers protection against the deadly H5N1 avian flu virus now circulating, its impact on any mutated strain of virus is not certain. However, experts say it could "prime" an individual's immune system so they will get stronger effects from a later, better-matched vaccine. The H5N1 strain of avian influenza has spread rapidly out of Asia and has killed more than 150 people who have come into close contact with infected birds. Experts fear it could trigger a pandemic, a global epidemic of flu that could kill millions, if it acquires the ability to pass easily from human to human. Rival companies including Sanofi-Aventis <SASY.PA>, Novartis AG <NOVN.VX> and Baxter International Inc. <BAX.N> are also racing to develop pandemic H5N1 vaccines.
