Résumé
Vaccine escape mutant may develop after immune prophylaxis with universal HBV vaccination. Aim of the study: to detect the frequency of HBsAg escape mutant among the patients with previous HBV infection and patients with HCV infection after full dose of HBV vaccination. A hospital control based study included 68 person. Twenty six with previous HBV infection patients, 25 chronic hepatitis C patients, and 17 apparently healthy persons as controls. Vaccination were carried out for all patients and control group. All patients and control groups were negative for HBs Ag before enrollment in this study. HBsAg, HbcAb, HBeAg and HBsAb were enrollment performed by micro particle immunoassay. HBV DNA and HBsAg mutants were performed by real time polymerase reaction [RT-PCR]. HBV DNA was detected in 10[38.5%] in HBV patients with previous infection and after full dose of vaccination. HBsAg mutants were detected in 8[30.8%] of them. In HCV patients with negative surface antigenemia HBV DNA was detected in 5 [20%] and HBsAg mutants were detected in 3[12%] of them. The frequency and levels of HBsAb in HBV patients with previous infection and after full dose of vaccination were significantly decreased when compared to those with HCV infection and healthy control group after dose of vaccination. From this study we concluded that the presence of HBsAg mutants in HBV and HCV patients with negative surface antigenemia after full dose vaccination .the measurement of HBV DNA by sensitive quantitative technique plays an important role in detection either with mutants in surface antigen or occult HBV infection [OBI]. Lower immune response was markedly observed after prophylactic vaccination of patients with previous HBV infection with and to lesser extent in those with HCV infection. HBcAb and or HBV DNA testing should be considered before HBV vaccination to avoid the vaccine induced pressure which may lead to development of HBV surface antigen mutations