Study On Preparation And Evaluation Immunity Effect Of Adjuvant For Live Vaccine Against Classical Swine Fever

Classical swine fever(CSF) is an often fatal and highly contagious viral disease of domestic pigs, which may result in devastating financial losses. Vaccine injection is an important method to prevent CSF. There are some disadvantages for the commonly used CSF vaccine adjuvants needed to be improved, such as strong side effects, low safety and immune effect, and high viscosity leads to inconvenient injection. The aim of this study is to develop the novel adjuvant for CSF vaccine that can enhance the immune effect of vaccine effectively. The safety, humoral immune responses and cellular immune responses of the O/W emulsion CSFV vaccine adjuvant were evaluated with BALB/c mice. In addition, the preparation of W/O/W emulsion adjuvant and polymer gel adjuvant were studied. The main research works are as follows:1. The O/W emulsion CSFV vaccine adjuvant was prepared by high pressure homogenization technique. Formulations and preparation parameters were optimized with response surface design. Its stability, particle size and polydispersity(PDI) and Zeta potential were characterized. The particle size of the O/W emulsion adjuvant prepared by optimized formulation and parameters was 100.4 nm, PDI 0.147, and zeta potential was-28.7 mV. The centrifugal stability experiment showed that the O/W emulsion adjuvant had good stability.2. The O/W emulsion adjuvant was alone inoculated into BALB/c mice by subcutaneous injection. Observed continuously two weeks and weighing every other day, its weight changes compared with the control group no obvious difference over time and did not appear caused by the death of adjuvant or evidentlocal and systemic adverse reactions. After two weeks, the mice were dissected the injection site, the heart, liver, spleen, lung and kidney all normal and no poisoning symptoms. The experiment results showed that the O/W emlusion adjuvant is safety.3. The O/W emulsion adjuvant was inoculated combined with CSFV vaccine into BALB/c mice by intramuscular injection. The results showed that the CSFV specific immune responses could be evoked in mice by co-inoculation with O/W emulsion as adjuvantand vaccine. The cellular immune response levels in co-inoculated groups were higher than those groups, with obvious phenomena of higher level of IFN-γ, IL-6 and IL-4 in serum. The result revealed that cellular immune capability increasingly improved withthe O/W emulsion adjuvant.4. The W/O/W emulsion adjuvant was prepared successfully by high speed dispersion and high pressure homogenization technology. Formulations and preparation parameters were optimized. The preparation of the optimized prescription was selected and showed that W/O/W emulsion adjuvant had excellent stability and appropriate viscosity.5. Formulations of the polymer gel adjuvant were studied. The polymer gel matrix, emulsifier, oil phase and high pressure homogenization processwere optimized.The particle size of the polymer gel vaccine adjuvant prepared by optimized formulation and parameters was 221.6 nm, PDI 0.114 and Zeta potential was –29.7 mV.