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. Postvaccination 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.