Which serologic marker indicates prior hepatitis B immunization?

The serologic marker that indicates prior hepatitis B immunization is the hepatitis B surface antibody (anti-HBs). When an individual receives the hepatitis B vaccine, the immune response leads to the production of anti-HBs, which signifies that the body has developed immunity against the virus. The presence of these antibodies demonstrates a previous successful immunization rather than an active infection.

The other markers listed play different roles in hepatitis B status. Hepatitis B core antibody (anti-HBc) indicates past or current infection, including both acute and chronic states, but does not distinguish between immunization and infection. Hepatitis B envelope antigen (HBeAg) is associated with active viral replication and indicates higher infectivity during chronic hepatitis B infection. Lastly, hepatitis B surface antigen (HBsAg) is a marker of active infection; its presence signifies that the person is currently infected with the virus. Thus, the presence of anti-HBs is the definitive marker for confirming immunization against hepatitis B.