Current issues that are associated with the development of HEPATITIS B VACCINE, combination VACCINEs, modes of administration, immunogenicity, and efficacy of different types of HEPATITIS B VACCINEs are reviewed. HEPATITIS B viral mutants can emerge as a result of either immune response or treatment options. Several studies are in progress on treatment of chronic HEPATITIS B infection by immunization with multiple antigenic components; DNA VACCINEs alone or with DNA encoded immunomodulatory cytokines; combination of VACCINE with antiviral drugs and cytokines; and genetic manipulation of antigen presenting cells. Integrating HEPATITIS B VACCINE doses into the global infant immunization program is not sufficient for HEPATITIS B virus (HBV) infection eradication. Implementing HBV schedule to high risk groups such as injection drug users, inmates of correctional centers, and persons at risk for sexually transmitted diseases, surveillance of HEPATITIS B infected subjects and refugees, access to immunization services and treatment is necessary. Further investigation is needed to assess factors that can impede an adequate antibody response, HBV variants, and the need for booster doses to preserve VACCINE-induced immunity, vaccinating schedule for older children, evaluation of those vaccinated but in persistent contact in HBV-endemic areas.

Background: The level of HBsAg in some chronic HEPATITIS B virus (HBV)-infected individuals may decline over time so that it is not detectable in serum.Objective: To assess the efficacy of HBV VACCINE in those who lost their HBsAg without seroconverssion to anti-HBs antibody.Patients and Methods: From April 1993 to December 2008, of 1603 chronic HBV-infected individuals, 34 (22 men and 12 women) became HBsAg-negative in follow-up visits, with no detectable anti-HBs antibody and HBV DNA in their sera. They received HBV vaccination at 0, 1 and 6 months (case group). Fifty-two subjects (30 men and 22 women) who were negative for HBsAg, anti-HBs and anti-HBc antibody, received HBV vaccination according to the said schedule (control group). Anti-HBs antibody was assessed one month after the last dose of vaccination in the both groups. Results: The mean±SD age of the case and control groups was 38±12.7 and 33.4±8.6 years, respectively (p=0.07). The sex distribution between these two groups were similar (p=0.652). The mean±SD years of follow-up for the case group were 7.6±4.5 years. Anti-HBs antibody level ³10 IU/L was found in 8 (24%) subjects in the case group and in 45 (87%) in the control group (p<0.001). The mean±SD anti-HBs antibody level in the case group was 68±32.66 and in the control group 344.6±38.9 IU/L (p<0.001).Conclusions: We found that nearly 24% of chronic HBsAg-positive subjects who lost their HBsAg responded to HBV and the remaining cases need to be followed for occult HBV infection.

Background - To determine the response of Iranian children to Cuban HEPATITIS B VACCINE. Methods - A total of 538 children who had received three doses of Cuban HEPATITIS B VACCINE were classified into 4 groups of 6, 12, 24, and 36 months after the third dose of vaccination. Every group was subdivided into nonresponders, hyporesponders, and good-responders. Results - Of 538 VACCINEes, 240 (44.6%) were females. In Group I, of 230 (42.75%) VACCINEes, 25 (10.9%) were nonresponders, 51 (22.1%) hyporesponders, and 154 (67%) good-responders. In Group II, consisting of 98 (18.2°/x), 18 (18.4°/x) were nonresponders, 38 (38.8°/x) hyporesponders, and 42 (42.6%) good-responders. In Group III, of 100 (18.58%) VACCINEes, 8(8%) were nonresponders, 32 (32%) hyporesponders, and 60 (60%) good-responders. In Group IV, with 110 (20.4%) VACCINEes, 31 (28.1%) were nonresponders, 30 (27.3%) hyporesponders, and 49 (44.5%) good-responders. Conclusion- Of the total 538 VACCINEes, 305 (56.7%) were good-responders, 149 (27.7%) hyporesponders, and 84 (15.6%) nonresponders. Both rates of VACCINEes and concentration of anti-HBs in the good-responders were low and the number of hyporesponders and nonresponders were high.