title: The geographical distribution of HBsAg subtypes.
mesh_terms: D000349:Africa; D001208:Asia; D001315:Australia; D000939:Epitopes; D005060:Europe; D006511:Hepatitis B Antigens; D006801:Humans; D009656:North America
chemical_list: D000939:Epitopes; D006511:Hepatitis B Antigens