14 DAY TRIAL // Researchers at Sanofi Pasteur, the vaccine division of Sanofi-Aventis, have announced today that the preliminary results of clinic tests for an adjuvant candidate H5N1 pre-pandemic influenza vaccine.
According to their statement, adding an adjuvant in the classic anti-flu vaccine improves the efficiency of the small doses. That would mean that supplies of the key element of the vaccine known as the antigen could be stretched further, AP said.
The tests made by Sanofi Pasteur in France on 300 volunteers showed that a 30 microgram-dose with an adjuvant in a two-dose regimen demonstrated an immune response at levels consistent with requirements of regulatory agencies for licensure of seasonal influenza vaccine.
Since 1997, outbreaks of H5N1 flu have caused the death or culling of tens of millions of birds and the infection of over 100 people have been infected, with a mortality rate of over 50%. As of November 1, 2005, 122 cases of infections in humans, resulting in 62 deaths, have been confirmed outside of China.
Sanofi Pasteur characterized the preliminary results as a sign of progress and providing direction for further development of a pandemic influenza vaccine.
Still, obtaining a response from the immune system is not enough to ensure that the vaccine will be able to protect humans against the infection. Another problem that requires a special attention is the need for a double injection over a two week period.
In addition, perfecting a vaccine against an epidemic before its outbreak is rather impossible, a perfect match with the strain being required.
Authorities are concerned that the H5N1 virus could mutate so that it becomes easily transmittable among humans leading to millions of deaths.
So far, most of the human infections have resulted only from direct or indirect contact with the infected birds, AP said.