title: Hepatitis B antigen subtypes-history, significance and immunogenicity.
abstract: Initial work showed that all hepatitis B surface antigens (HBs Ag) were identical. Subsequent, additional studies revealed that hepatitis B surface antigens have a group reactive determinant, a, plus additional specificities which are not universally present on all antigens. Four well-defindd subtypes of HBs Ag exist (HBs Ag/adw, HBs Ag/ayw, HBs Ag/adr, HBs Ag/ayr) but additional subtypes will be forthcoming as newly described determinants are confirmed. The subtype specificities are determined by the hepatitis B virus and not the host. Subtypes of HBs Ag are already of great use in the epidemiology of hepatitis B virus infections; yet they may have additional significance. Current work on HBs Ag subtypes is limited by the ability to find or produce antibodies to other than the a or group reactive determinant. The other determinants appear to be less immunogenic than a.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000302:isolation & purification; D000917:Antibody Formation; D000918:Antibody Specificity; D002462:Cell Membrane / Q000276:immunology*; D000939:Epitopes; D006168:Guinea Pigs; D006509:Hepatitis B / Q000276:immunology*; D006511:Hepatitis B Antigens / Q000145:classification*; D006515:Hepatitis B virus / Q000145:classification / Q000302:isolation & purification*; D006801:Humans; D007114:Immunization
chemical_list: D000914:Antibodies, Viral; D000939:Epitopes; D006511:Hepatitis B Antigens