SANOFI PASTEUR PRESENTS NEW DATA ON H5N1 PRE-PANDEMIC VACCINE

Sanofi pasteur, the vaccines business of sanofi-aventis, announced that its H5N1 pre-pandemic vaccine induces antibodies that neutralize additional H5N1 circulating virus not included in the original vaccine formulation. These data, presented at the International Conference on Influenza Vaccines for the World in Vienna, Austria, further demonstrate the value of sanofi pasteur's candidate vaccine for pandemic preparedness, according to the company.

Analysis of blood samples from volunteers who participated in the first Phase I trial conducted in 2005 with the company's H5N1 pre-pandemic vaccine showed the potential of the vaccine to protect against recent H5N1 circulating viruses.

Vaccinated volunteers developed serum antibodies that were able to neutralize diverse H5N1 viruses (A/turkey/Turkey/1/2005 wild-type and reverse-genetic clade 2, and A/Vietnam/1194/2004 wild-type and reverse-genetic clade 1). The tested vaccine contains the A/Vietnam/1194/2004 reverse-genetic strain. These more recently circulating H5N1 viruses have caused human infections in several European countries in 2005 and 2006, and continue to cause infections in parts of Southeast Asia.

Among volunteers who developed antibodies to the vaccine, cross-neutralization results were similar in those who received high antigen (30 micrograms) and those who received lower antigen (7.5 micrograms) doses. Results were also similar in volunteers who received alum-adjuvanted and non-adjuvanted vaccine (alum is an additive commonly used to increase the immune response to vaccines). The ability to provide cross-protection against diverse influenza strains with less antigen is an important feature for any pandemic or pre-pandemic vaccine, as it will allow for production of more doses to protect the largest number of people in the case of a pandemic, according to the company.

These new data reinforce conclusions of the Phase I study published in May, which demonstrated that multiple dosage formulations of the H5N1 pre-pandemic vaccine candidate generates an immune response with and without an adjuvant.