Vaccine producers remain in slow lane
Vaccine developers are hard-pressed to find ways to manufacture H5N1 vaccines faster, or to lower their effective dosage, to protect as many people as possible in the event of a flu pandemic, says a vaccine maker.
Vaccine producers still had to rely on egg-based technology, in place for 60 years, in case a pandemic vaccine was necessary in the next five years, executives of French-based Sanofi Pasteur said at their plant in Marcy L'Etoile near Lyons, France.
Vaccine developers are focusing on H5N1 because it is regarded as the virus most likely to evolve into a pandemic strain.
'We can only produce flu vaccines on a large scale through the use of eggs,' said Alain Bernal, vice-president of communications.
He said Sanofi Pasteur had been producing seasonal flu vaccines using cell cultures in minute quantities, but this was still at the developmental stage.
Mr Bernal said the four main vaccine makers still relied on egg-based technology to make flu vaccines and would have to rely on it for a pandemic flu vaccine.
'We have injected 1.2 billion doses with no problems, so it has a good safety record,' he said. '
'But we believe that in the long term, there are alternative techniques, such as cell culture. But as of today, there is no manufacturer who can produce in big volumes. It will take five years to develop.'
Sanofi Pasteur will next month announce the results of clinical trials of an H5N1 vaccine that last month became the first vaccine licensed by the US Food and Drug Administration for humans against bird flu.
Cell-culture technology makes it possible to develop and produce flu vaccines faster than with the egg-based method, which takes about six months. It also is considered safer, because there is no production of live flu viruses.
Drug company Protein Sciences said recently it expected to obtain approval in the United States for its cell-culture-based flu vaccine.
British company GlaxoSmithKline reported in July that its bird-flu vaccine, made from deactivated H5N1 virus, triggered a good response in humans at a much lower dosage than other vaccines, including that of Sanofi Pasteur.
