Europe backs Glaxo's pandemic flu vaccine

A chicken is seen during a bird flu preparedness exercise in Singapore October 4, 2006. A first-generation experimental bird flu vaccine for use in humans from GlaxoSmithKline Plc has won outline support from European regulators.

LONDON (Reuters) - A first-generation experimental bird flu vaccine for use in humans from GlaxoSmithKline Plc has won outline support from European regulators.

The European Medicines Agency said on Friday it had recommended granting a license to Daronrix, a "mock-up" vaccine that could be used as the base for producing a shot to protect people in the event of a pandemic triggered by bird flu.

Daronrix is the first vaccine to win such endorsement.

But it would only be used once a pandemic has officially been declared and would not be stockpiled in its current form, since it will have to be adapted to include the exact pandemic virus strain.

As such it marks just one approach in vaccine preparations.

Glaxo, like several of its rivals, is also working on a second-generation vaccine against the H5N1 virus that causes bird flu and plans to submit this product for regulatory approval within the next few weeks.

Its second vaccine is more flexible and could potentially be used as part of a pre-pandemic vaccination campaign, helping to prepare the human immune system in advance of a pandemic.

MASS PRODUCTION

The later vaccine, which Glaxo has already sold to some governments, has the added benefit of needing very little antigen to produce a strong immune response, allowing for production of large quantities for mass vaccination.

A key challenge in the race to produce a vaccine for millions of people around the world is how to make the maximum number of shots from the minimum amount of antigen, or active ingredient.

The U.S. government has ordered H5N1 vaccines from companies including Glaxo, Sanofi Pasteur and Novartis, and other governments including Switzerland are also building stockpiles.

Industry analysts say the orders could give a significant boost to sales of Glaxo and its rivals next year.

The H5N1 avian flu virus mostly affects birds, but it can occasionally infect people and has so far killed more than 150 since late 2003.

Experts fear the virus will evolve just slightly into a form that people can easily catch and pass to one another, in which case the transmission rate would soar, causing a pandemic in which millions of people could die.

Any stockpiled H5N1 vaccine will not perfectly match whatever new strain emerges, but studies suggest it might help protect people from death.

Glaxo shares, which fell early in the day on news of approval of a generic version of its antidepressant Wellbutrin XL, regained some ground to stand 0.2 percent lower at 13.44 pounds by 1205 GMT.

The European Medicine Agency's positive opinion on Daronrix will now go to the European Commission, which has final responsibility for granting a license for new drugs and vaccines.