[Reciprocal priming-boosting role of HBsAg and DNA vaccines].

Objective: To evoke more effective humoral and cell-mediated immunization against hepatitis B virus (HBV) infection.

Methods: HBsAg-primed mice were boosted with HBs-DNA vaccine, and HBs-DNA-primed mice were boosted with HBsAg vaccine. Anti-HBs level was assayed by ELISA and cytotoxic T lymphocyte (CTL) response was tested by lactic acid dehydrogenase (LDH) releasing method two weeks after the boosted immunization.

Results: Anti-HBs level and CTL responsive rate at the effector/target cell ratio of 100:1 were 0.38 and 36% in HBsAg/HBs-DNA vaccination group, 0.32 and 27% in HBs-DNA/HBsAg vaccination group, 0.48 and 1.5% in HBsAg/HBsAg vaccination group, 0.24 and 68% in HBs-DNA/HBs-DNA vaccination group, respectively.

Conclusion: Priming with HBs-DNA vaccine followed by boosting with conventional HBsAg vaccine results in greater antibody response (F = 21.19, P < 0.05), and CTL response after HBsAg vaccination can be improved by boosting with HBs-DNA vaccine (F = 165.59, P < 0.05). It brings to better efficacy by combining HBsAg vaccine with HBs-DNA vaccine.