Hepatitis B Vaccine: Immunity, Efficacy and Types.

Current issues that are associated with the development of hepatitis B vaccine, combination vaccines, modes of administration, immunogenicity, and efficacy of different types of hepati-tis B vaccines are reviewed. Hepatitis B viral mutants can emerge as a result of either im-mune 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 antivi-ral 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.