The vaccine, which uses a proprietary adjuvant, enabled over 80% of subjects who received 3.8 micrograms of antigen to demonstrate a strong seroprotective immune response.
According to the company, this level of seroprotection meets or exceeds target criteria set by regulatory agencies for registration of influenza vaccines. Efficacy results at these levels of antigen dosage have also not been reported for any other H5N1 vaccine in development to date, including those using other adjuvants such as alum.
“These excellent clinical trial results represent a significant breakthrough in the development of our pandemic flu vaccine. This is the first time such a low dose of H5N1 antigen has been able to stimulate this level of strong immune response,” said JP Garnier, GlaxoSmithKline’s CEO.
“All being well, we expect to make regulatory filings for the vaccine in the coming months,” he continued.
The results were based on an interim analysis of a clinical trial conducted in Belgium which involved 400 healthy adults aged 18-60 years of age. The vaccine tested was produced from inactivated H5N1 virus and contained a novel, proprietary adjuvant.