Aim: Study of immunogenicity and protective efficacy of a novel inactivated vaccine with chitosan against influenza A/H1N1/2009.
Materials and methods: Influenza virus A/California/7/2009 (H1N1) strain was used in the study. Mice were immunized twice (21 day interval) with experimental samples of inactivated influenza vaccine: No. 1--without the addition of chitosan, No. 2--with addition of chitosan. The blood was obtained 21 days after the first and 10 days after the second immunization with the vaccines and was treated with RDE. Antibody levels were evaluated in HI reaction.
Results: HI reaction method showed that antibody titers induced after immunization of vaccine No. 2 were higher than those induced after immunization with vaccine No. 1. Evaluation of protective efficacy of the vaccines against an experimental form of influenza infection in mice showed that after immunization with vaccine that does not contain chitosan the level of virus accumulation does not differ from the control statistically significantly (p < or = 0.05), at the same time the level of virus accumulation in the lungs of infected animals immunized with chitosan containing vaccine significantly (significantly with 95% probability) decreased by an average 3.01g when compared with control.
Conclusion: Comparative analysis of immunogenicity and protective efficacy of experimental samples of inactivated influenza vaccine against influenza A/H 1N1/2009 showed that the vaccine with the addition of chitosan stimulates the formation of a higher immune response and promotes a more significant suppression of influenza A infectious agent reproduction in the lung target-organ.