[Chitosan as an adjuvant for parenteral inactivated influenza vaccines]

Addition of 0.5% chitosan derivative to parenteral inactivated influenza vaccines increased antibody titers in the single immunization of mice by 4-5 times while double immunization showed 6-to-10-fold increases as compared with immunization without chitosan. Moreover, chitosan-containing vaccines induced the generation of antibodies to the drift variants of influenza virus. When the mice were given inactivated influenza virus A/H5N2 vaccine containing chitosan, immunogenicity and protective efficacy were much higher than when they received a vaccine containing no chitosan.