GSK’s bird flu vaccine shows wider protection: study
The H5N1 flu strain, which is sweeping through bird populations in Europe and Asia, is thought by experts to be the most likely candidate to mutate and trigger the next global pandemic.
The challenge for drug makers is to have sufficient quantities of a vaccine ready early enough to allow large populations to be inoculated. Waiting for a pandemic to break out to find out the exact strain would delay the first vaccine batches for four to six months, given the illness time to become widespread.
While the virus has not yet mutated into a form that can be transmitted from human to human, drug makers are working on vaccines based on known strains in the hope that they will be similar enough to prime immune systems to fight the pandemic bug.
In one study, GSK's pre-pandemic vaccine containing the Vietnam H5N1 antigen was found to elicit a strong cross-immune response in humans infected with the Indonesian strain of the virus.
The response was seen at low doses, which Glaxo believes was due to the adjuvant used in the vaccine. An adjuvant is a substance added to a drug to enhance its effect.
Glaxo said that could mean by adding its proprietary adjuvant, manufacturing capacity – another big challenge in the face of a mass global outbreak – could be increased.
A second animal study showed that Glaxo's vaccine could protect against two diverse H5N1 flu strains, again at very low levels. The vaccine containing the Vietnam strain protected against the vaccine virus and provided 96 pct cross-protection against a lethal challenge with the mutated, or 'drifted' Indonesia strain.
Rip Ballou, GSK's Vice President of clinical research and development, said the results give a boost to hopes that pre-pandemic vaccination is a viable strategy.
'The generic difference between these two viruses is quite substantial, so I think it certainly bodes well for its ability to broadly cross-protect,' he said. 'And we think this cross immunity is certainly been driven by the adjuvant which is unique to GSK.'
Ballou said GSK is already talking to governments who might purchase the vaccine prior to it gaining marketing approval.
The shot is currently under review by European medicine regulators.
Sunday, March 11, 2007
Hương 0904474161 Ha Noi
Hương 0904474161 Ha Noi