Abstract:

 Objective   To study the optimal immunization of bivalent DNA vaccine encoding
Schistosoma japonicum 14 kDa (Sj14) and 23 kDa (Sj23) with the different immunized dosages, in-
oculated times, inoculated routes and challenge time after the last immunization. Methods  Con-
struction and preparation of the bivalent DNA vaccine of Schistosoma  japonicum 14 kDa (Sj14) and
23 kDa(Sj23) were porformed. A total of 110 male BALB/c mice, about 5-6 weeks old, were ran-
domly divided int0 11 groups,2 were the control groups and 9 were the experimental groups, de-
signed with four factors in orthogonal trial.  Each mouse of the groups was infected with (40± 2)
cercariaes of Schistosoma japonicum in the 30 th day after last immunization, and 45 days after the
infection, the mice were sacrificed, and the burden of the adult worms was invetigated. Results
There was no significant difference in the impact on immunity protection excited by the different fac-
tors and different levels of each factor (P>O. 05).  Conclusion   According to this experiment, the
optimal immunization for this vaccine is 50 ptg per mouse, twice immunization and intradermal injec-
tion, and the period of efficacy is at least 12 weeks after the challenge.

Key words:  Schistosoma japonicum, Bivalent DNA vaccine, Sj14, Sj23, Optimal immunization

摘要：

目的研究双价DNA疫苗pVIV02-Sj14-Sj23在不同免疫剂量、免疫次数、免疫有效时间及不同免疫途径的最佳免疫方案。方法  构建和制备双价DNA疫苗pVIV02-Sj14-Sj23；110只雄性BALB/c小鼠随机分成11组，每组10只，按照四因素三水平分成2个对照组和9个实验组。各组统一在末次免疫后30 d每鼠感染（40士2）条日本血吸虫尾蚴，感染后45 d剖杀，计数成虫虫荷。结果双价DNA疫苗9个实验组获得40.14%～62. 68%的减虫率。通过SPSS 12．O进行正交设计的统计分析：F值<F'临界值，P>O. 05。免疫剂量，免疫次数，免疫途径和免疫有效时间几个因素间差异无统计学意义。结论实验结果提示该疫苗的较好免疫方案为：50 Vg/只，免疫2次，采取皮内注射，免疫有效时间至少为12周。

关键词:  日本血吸虫；双价DNA疫苗；Sj14；Sj23；免疫方案