Abstract: 　Objective To explore the optimal immune doses of recombinant antigen rSjGST-32, with QuilA as adjuvant. Methods BALB/c mice were immunized with doses of 50, 100 and 200 μg rSjGST-32/mouse plus 50 μg QuilA adjuvant. QuilA and PBS were used as controls. Levels of specific antibodies were detected by ELISA. The mice were challenged 4 weeks after last vaccination. Worms and eggs collected from the livers of mice were counted 45 days after challenge. Results As compared with the control groups, the worm reduction rate in the 50, 100 and 200 μg experiment groups was 38.1%, 47.8% and 48.8%, respectively. The reduction rate of liver eggs per gram (LEPG) was 39.1%, 53.5% and 53.6%, respectively, and the reduction rate of the liver eggs per female (LEPF) was 22.5%, 22.8% and 21.8%, respectively. The specific antibody titers in sera reached 1∶51 200, 1∶102 400 and 1∶102 400, respectively before challenge. Conclusion The results show that for vaccinating BALB/c mice, the optimal antigen dose is 100 μg of recombinant rSjGST-32 plus QuilA adjuvant.

Key words: Schistosoma japonicum, recombinant protein, antigen dose, immune effect, SjGST-32