Currently, there are various approaches for developing therapeutic vaccines for chronic hepatitis B patients. Previously, an antigen-antibody-based therapeutic vaccine (YIC) has been conducted in a double-blind placebo controlled phase IIb clinical trial in 242 chronic hepatitis B patients. At the end of follow-up for 24 weeks, HBeAg sero-conversion rate was 21.6% in the 60 μg immunized group, compared to 9% in the alum immunized control group (p=0.03). To analyze the correlation between HBeAg-seroconversion, and decrease of serum HBsAg and HBV DNA, serum samples were back quantified for serum HBsAg and HBV DNA collected at baseline, end of treatment, and end of follow-up from patients who were treated either with 60 μg of YIC, or with placebo. Patients were dichotomized to HBeAg sero-converted and non-converted groups in comparison with patients in the placebo group. The correlations between HBeAg seroconversion and the decrease of HBsAg, HBV DNA and ALT levels during study period were analyzed using a logistic regression model. Results showed marked and sustained reduction of HBsAg, HBV DNA and ALT level in HBeAg sero-converted patients compared to those in patients of HBeAg non-converted and placebo groups. Reduction of HBV DNA and elevation of ALT was markedly associated with HBeAg seroconversion with an adjusted OR of 0.09 (95%CI: 0.01-0.62) and 0.08 (95%CI: 0.02-0.37) respectively after adjusted by age and sex, while reduction of HBsAg level was close to of significance (p=0.054). Analysis indicated that HBeAg sero-conversion was a reasonable endpoint for therapeutic vaccination.
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