Efficacy and limitations of a specific immunotherapy in chronic hepatitis B

This controlled study aimed to evaluate the efficacy and potential side effects of hepatitis B virus (HBV) vaccination as active immunotherapy in HBV-related chronic hepatitis.

The 118 included patients were 'naive' subjects who had never received any previous anti-HBV therapy, showed detectable serum HBV DNA and had biopsy-proven chronic hepatitis. In a 12-month follow-up they were given either five intramuscular injections of 20 microg of a preS2/S (GenHevac B, Pasteur-Mérieux) (n = 46) or an S vaccine (Recombivax Merck & Co.) (n = 34) or no treatment as a control (n = 37). The efficacy of vaccination was evaluated by testing for serum HBV DNA negativation using a standard liquid hybridization assay.

Three months after the first three vaccine injections, the percentage of serum HBV DNA negativation was higher in the vaccine groups (16.3%) than in the control group (2.7%) (P = 0.033, by the chi2 Pearson test) and was more frequently observed in patients who had pretreatment viremia >200 pg/ml (none in the control group vs. 16.7% in the vaccinated groups) (P = 0.025). After 12 months follow-up and five vaccine injections, there was no difference in the rate of serum HBV DNA negativation between vaccinated and unvaccinated subjects but HBV vaccines significantly decreased the HBV viral load between the sixth and twelfth months (P = 0.04) in contrast with the control group. The rate of HBe/anti-HBe seroconversion after 6 months of follow-up occurred only in eight (13.3%) vaccinated patients and in one (3.6%) of the controls. Disappearance of serum HBsAg was not observed in any of the patients.

This controlled study offers direct evidence that the HBV vaccine may decrease HBV replication in chronic hepatitis B patients. It also emphasizes the need for reinforced immunization strategies as well as combination therapies.