Disclosed is a process for obtaining hybridoma cell lines which produce human antibodies capable of binding to the hepatitis B virus surface antigen (HBVsAg), as well as the hybridoma cell lines, and antibodies produced by the cell lines. Also disclosed are various uses of said antibodies in the prevention and treatment of HBV infection. Peripheral blood lymphocytes obtained from human donors having a high titer of anti HBVsAg antibodies are engrafted into normal strains of mice which were lethally irradiated and radioprotected with SCID bone marrow. After immunization of such chimeric mice with HBVsAg, human cells are obtained from the mice spleens and fused in vitro with heteromyeloma cells to generate hybridomas secreting human antibodies having a high affinity and specificity to HBVsAg.