BioSante's flu vaccine adjuvant impresses in trial

US firm BioSante Pharmaceuticals says that data presented at this year's Novel Vaccines Conference in Cambridge, Massachusetts, indicate the considerable progress it has made in developing its nanoparticle-based pandemic H5N1/bird flu vaccine adjuvant, BioVant. The findings, which are from a paper entitled Calcium Phosphate Nanoparticles as a Candidate Adjuvant for Influenza/Avian influenza vaccine, include the results from several preclinical studies and hemagglutinin inhibition assays.

The study program was designed to determine BioVant's impact on immune response in mice infected with either annual human influenza or the H5N1 avian flu strain. Results indicated that animals which received the combined BioVant vaccine produced higher quantities of avian-flu specific antibodies than those getting the vaccine alone. In addition, the increase in avian flu antibody levels was sustained throughout the study, which BioSant said indicates a good duration of immunity.

Earlier this year, BioSant reported data which demonstrated the adjuvanting effect of BioVant which, after a priming and a booster dose, elicited an immune response in rodent models that was four times greater than in animals provided with the H5N1 antigen alone. At the time, the firm said that, because the trial had demonstrated effectiveness using only 3mcg of viral antigen, BioVant has the potential to bring about considerable dose-sparing when combined with human vaccine, adding that the only currently Food and Drug Administration-approved product uses 90mcg of antigen (Marketletter July 23).