A bird flu vaccine for humans that uses only a very low dose of active ingredient has proved effective in clinical tests and could be mass produced in 2007, its maker GlaxoSmithKline said today.
Europe's biggest pharmaceuticals group said it was on track to start manufacturing by the end of 2006 and could make hundreds of millions of doses next year, assuming the product is approved by regulators.
It will probably cost around the same as a conventional flu shot - about £4 sterling ($7.40) - and Glaxo is talking to groups such as 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 rivals in development because of the proprietary adjuvant used. 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.
Glaxo's vaccine contains just 3.8 micrograms of antigen, yet more than 80 per cent 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.