Immunotherapy of chronic hepatitis B by anti HBV vaccine.

Vaccine therapy is now used in various infectious diseases. The hepatitis B virus (HBV) leads to chronic infection in around 5% of patients with a high risk of chronic active hepatitis which may result in cirrhosis and hepatocellular carcinoma. The partial efficacy of antiviral therapies (40% of sustained inhibition of HBV replication), their cost, the numerous side effects and the immune-mediated pathology of HBV infection explain the emergence of new immune therapies in treating HBV infection. Experimental and clinical arguments are in favor of vaccine therapy in HBV chronic infection. Thirty-two consecutive chronic HBsAg carriers with chronic hepatitis and detectable serum HBV DNA were given 3 standard injections of the GenHevac B vaccine at one month intervals. Six months after the first injection, 12 patients (37.5%) had undetectable HBV DNA while 3 others showed significant decrease in HBV DNA titers. Eight of these 15 responders received a standard course of alpha-interferon (5 MU thrice weekly subcutaneously for 4 months) and all still had undetectable HBV replication. By contrast, among 13 (of the 17) non responders to vaccine who were given alpha-interferon, only 3 stopped HBV replication. In summary, serum HBV DNA disappeared in 18 of the 32 patients (53.1%) who were given vaccine therapy, with or without interferon. Vaccination was uneventful. Active immune therapy against HBV appears as efficient and less expensive than antiviral therapies in stopping HBV replication. Such a result should be confirmed by controlled randomized trials.