The present invention provides an antibody that binds to the surface antigen (HBsAg) of hepatitis B virus (HBV) to neutralize the hepatitis B virus. The surface antigen-binding site of the antibody was found to play a very important role in viral replication, and when a mutation in the site occurs, viral replication is significantly inhibited, and thus at least HBV virus cannot cause a mutation in the site.In the present invention, it was confirmed by the use of patient-derived virus that the antibody of the present invention binds to either YMDD mutant hepatitis B virus, produced by conventional viral replication inhibitors, or G145R HBsAg mutants to which plasma-derived HBIG (hepatitis B immunoglobulin) does not bind.In addition, the in vivo effect of the antibody of the present invention was examined using chimpanzees which are unique animal models for hepatitis B virus. As a result, it was found that the antibody has the effect of neutralizing even wild-type hepatitis B virus in the in vivo model. Thus, it can be seen that the antibody of the present invention has the ability to bind not only to wild-type hepatitis B virus, but also mutant hepatitis B viruses having a polymerase YMDD mutant and a surface antigen G145R mutation, as well as various mutant viruses derived from patients.Thus, the antibody of the present invention can be effectively used for the prevention or treatment of infections with not only wild-type hepatitis B virus, but also mutant hepatitis B viruses.
