Patients and medical personnel of some hemodialysis centres of the north-west region of the Russian Federation were examined for HB-virus infection markers using enzyme immunoassays. Subjects free of HB markers were immunized with ENGEPIX-B vaccine. Immunogenicity of the vaccine was assessed one month and one year after the immunization. Epidemiological HB factors in hemodialysis centers were studied on the simulation computer model. HB-virus-containing blood transfusion factor is not the only determinant of HB-virus infection prevalence. The virus can be transmitted via hemodialysis facilities. Immunization effects proved inferior in the hemodialysis unit patients. It is stated that vaccinoprophylactic policy in the patients of the dialysis centers and relevant equipment need serious improvement to prevent hepatitis B outbreaks.