In a clinical trial, 80% of volunteers who received two vaccine doses containing 3.8 mcg of antigen with an adjuvant (a chemical that stimulates the immune system) had a strong immune response, the British-based company said in a news release. A typical dose of seasonal flu vaccine is 15 mcg.
"This is the first time such a low dose of H5N1 vaccine has been able to stimulate this level of strong immune response," GSK Chief Executive Officer J.P. Garnier said in the news release.
By comparison, an H5N1 vaccine developed by Sanofi Pasteur induced a good immune response in 67% of volunteers who received two 30-mcg doses with an adjuvant, according to findings reported in May. The US government is stockpiling the Sanofi vaccine.
Garnier called the GSK vaccine a breakthrough because, with the effectiveness of the low dose, a given amount of antigen will go much further than it would otherwise.
"The meaning of this is that we are going to be in a position, starting later this year, to produce hundreds of millions of doses of an effective pandemic vaccine, so this is a big breakthrough," Garnier said on BBC Radio, as reported today by Agence France-Presse (AFP).
World influenza vaccine production capacity is too low in event of a deadly pandemic flu outbreak. A vaccine that is potent in such a small dose greatly expands the number of doses of vaccine that could be made in a year in response to a deadly pandemic.
Previous attempts to produce a low dose vaccine had been unsuccessful, with required doses as high as 180 micrograms. Companies then tried adding an adjuvant – a chemical which stimulates the immune system and increases the potency of a vaccine. But, again, results were disappointing.
We need newer and far more easily scaled vaccine production technologies. The lead time for vaccine production is several months. The production capacity is low because only a small fraction of the world's population gets vaccinated for the flu in typical years. A better vaccine production method would be faster and scale up rapidly with easily produceable capital equipment.
|Share |||Randall Parker, 2006 July 26 10:55 PM Dangers Natural Bio|