Sanofi pasteur, the vaccines business of the sanofi-aventis Group, has delivered more H5N1 vaccine to the US government including investigational doses formulated with an adjuvant.

Sanofi pasteur has shipped to the US National Institutes of Health (NIH), part of the US Department of Health and Human Services (HHS), 15,000 investigational doses of a vaccine to protect against the H5N1 influenza strain. Prepared with different levels of antigen, the investigational doses will be used in the NIH's clinical studies to determine the optimal formulation of the vaccine, informs the company release.

The investigational doses include the use of the adjuvant, aluminum hydroxide (alum), that could increase the vaccine's effectiveness and enable the use of fewer antigens in each dose. The end result could be a greater number of doses available to immunize more people.

In addition, the company has completed production of additional bulk-concentrate of the H5N1 vaccine antigen for the US government stockpile. Once the optimal dosage is established, the bulk-concentrate antigen will be ready for final formulation and filling into doses.

The additional H5N1 bulk-concentrate vaccine represents a broadening of a contract the company signed in September 2005 with the US Department of Health and Human Services (HHS) to produce a stockpile of the H5N1 vaccine valued at $100 million. The additional bulk concentrate vaccine just produced is valued at $50 million and will support US Department of defence requirements.