GlaxoSmithKline has been boosted by the news that the US government has put in another major order for the firm’s bird flu vaccine.

The firm noted that the US Department of Health and Human Services has placed a second order for 22.5 million doses of bulk H5N1 antigen for the government's pre-pandemic influenza stockpile, following the initial purchase of five million doses in November last year. GSK’s manufacturing plant in Sainte Foy, Canada, will produce the vaccine, which will be stored at a site in Marietta, Pennsylvania, USA.

GSK added that it has started the first of its clinical trials of the vaccine in North America, initiating a Phase I/II study involving 675 participants between the ages of 18 and 64. The trial will test its H5N1 antigen alone and in combination with an adjuvant, and results are expected in early 2008. This will be followed by a Phase III study later this year which is expected to enrol some 4,400 subjects.

Ripley Ballou, the firm’s vice president of clinical development for flu, said that the initiation of these trials “underscores the importance of GSK’s $2 billion investment in 2005 to create a new influenza vaccine infrastructure in North America”.