Europes biggest pharmaceuticals group said it was on track to start manufacturing by the end of 2006, assuming the product is approved by the regulators. It will probably cost around 4 pounds ($7.40) the same as a conventional flu shot and Glaxo is talking to groups like the Bill & Melinda Gates Foundation and the Global Fund to Fight AIDS, TB and Malaria about funding it in poor countries.
Glaxo believes its H5N1 vaccine will work more efficiently than rival ones in development because of the proprietary adjuvant used in its manufacture. Adjuvants are additives put into vaccines that boost the immune system and make it respond more efficiently.
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. Antigen is produced in chicken eggs in a slow and laborious process.
Glaxos vaccine contains just 3.8 micrograms of antigen, yet more than 80% of healthy adult volunteers who received two doses had a strong immune response. That level of protection meets or exceeds requirements set by regulatory agencies for approving new flu vaccines, and is twice as good at half the dose as results with an experimental vaccine produced by Sanofi-Aventis.
Glaxo chief executive Jean-Pierre Garnier said it was a significant breakthrough.
All being well, we expect to make regulatory filings for the vaccine in the coming months, he said. While Glaxos vaccine offers protection against the deadly avian flu virus now circulating, its impact on any mutated strain is not certain.
Experts say it could prime a persons immune system so they will get stronger effects from a later, better-matched vaccine. Glaxo said it would also study the ability of its vaccine to offer cross-protection to variants of the virus.