RESUMO
@#Objective To evaluate the immune effect of the diphtheria toxoid(DT)vaccine using chitosan as adjuvant on mice,so as to provide an experimental basis for the preparation of novel adjuvant vaccines of DT.Methods A total of 30 male C57BL/6 mice were divided into mucosal immunization group and humoral immunization group,and each group was randomly divided into 6 groups:negative control group(PBS),positive control group(DT),aluminum adjuvant group,chitosan adjuvant group(final solution with 0.5% chitosan),aluminum adjuvant vaccine group and chitosan adjuvant vaccine group,with 5 mice in each group. Mucosal immunization group and humoral immunization group were inoculated with 500 μL PBS buffer,10 μg DT,500 μg aluminum adjuvant and 500 μL chitosan adjuvant per mouse by nasal drip and intraperitoneal injection respectively. The mice were observed for the status,collected for the eyeball serum before inoculation(0 d)and 7,21,35 d after inoculation,and collected for the nasal lotion simultaneously. The levels of IgG antibody in serum and sIgA antibody in nasal lotion were detected by ELISA.Results After intraperitoneal injection and nasal drip of chitosan adjuvant vaccine,the mental and behavioral state of mice was normal. Chitosan adjuvant vaccine effectively induced the IgG antibody against diphtheria in mice with not significant difference,compared with the classic aluminum adjuvant vaccine group(F = 127.926 > F_(0.05(1,8)),P > 0.05);It also induced the production of sIgA in mice,which was significantly higher than that in the classical aluminum adjuvant vaccine group 21 d after immunization(F =127.926 > F_(0.05(1,8)),P < 0.05).Conclusion Chitosan adjuvant DT vaccine can effectively stimulate the mucosal immunity and humoral immunity in mice with good safety,and has the potential to be an alternative to aluminum adjuvant for vaccine preparation,which can be considered as nasal drop vaccines.