GlaxoSmithKline has developed an effective vaccine against the H5N1 strain of bird flu that it expects to file for approval in a matter of months. The company said its H5N1 pandemic flu vaccine achieved a high immune response, enabling over 80% of subjects who received a low dose to demonstrate adequate protection. While GSK has yet to publish the results, it said the tested level was 3.8 micrograms of antigen. In a statement, GSK CEO JP Garnier said, “This is the first time such a low dose of H5N1 antigen has been able to stimulate this level of strong immune response,” adding, “All being well, we expect to make regulatory filings for the vaccine in the coming months.” The firm said that the level of protection meets or exceeds target criteria set by regulatory agencies. Like other bird flu vaccines in development, GSK’s is on a fast track for approval with the US FDA and the European Medicines Evaluation Agency. The news could give GSK an advantage over rival Sanofi-Aventis, which also is developing a vaccine based on the H5N1 strain. While a pandemic bird flu strain has yet to emerge, companies are developing vaccines based on the existing H5N1 strain to give humans some form of protection.