Specific hepatitis B vaccine therapy in inactive HBsAg carriers: a randomized controlled trial

Background: Hepatitis B virus (HBV) vaccine therapy has two major areas of application: for preventive purposes and for treating patients with chronic hepatitis B. This study aimed to investigate the effect of therapeutic vaccination of inactive hepatitis B surface antigen (HbsAg) carriers using a recombinant hepatitis B vaccine in a randomized-controlled study. Patients and Methods: The 71 studied patients had never received prior antiviral therapies, were anti-HBe positive, had undetectable HBV-DNA and persistently normal alanine transaminase levels. 31 patients were given three 20 mg intramuscular injections of a preS2/S vaccine (GenHevac-B) on days 0, 30 and 60 and the remaining 40 patients were included in the control group. The efficacy of vaccination was evaluated by testing for HBsAg seroconversion to anti-HBs. Post-vaccination follow-up was for 12 months after the first dose. Results: At the end of the follow-up, three out of 31 patients (10%) who received vaccine therapy were able to clear HBsAg from their sera and concomitantly develop anti-HBs antibodies. In contrast, none of the 40 control patients who did not received vaccine therapy had decreased their levels of HBsAg or elicited anti-HBs antibodies (p = 0.079). In three vaccinated patients serum HBsAg became undetectable approximately by the 3rd month of vaccine therapy and HBsAg seroconversion was seen to be durable in all patients in the follow-up period. Conclusion: This study offers the first direct evidence, based on a controlled study, that the recombinant HBV vaccine has no great effect in enhancing the rate of HBsAg seroconversion in inactive HBsAg carriers. More efficient strategies, such as an increase in the dose and number of immunizations, should be evaluated further in large controlled trials.