Which blood test indicates the presence of immunity against Hep B?

Which blood test indicates the presence of immunity against Hep B?

• A. HBsAb
• B. HBsAg
• C. HBcAb
• D. HBeAg

Answer: (A)

Immunity to hepatitis B is indicated by the Hepatitis B surface antibody (HBsAb), also known as anti-HBs. This antibody appears in the blood after successful vaccination or recovery from hepatitis B infection, signaling protection against future infection. A positive anti-HBs means the person is immune. In contrast, the Hepatitis B surface antigen (HBsAg) shows an active infection, not immunity. The core antibody (HBcAb) reflects past or current exposure to the virus but does not by itself prove protective immunity. The e antigen (HBeAg) indicates active viral replication and high infectivity, again not immunity. So the presence of anti-HBs specifically confirms immunity.

Immunity to hepatitis B is indicated by the Hepatitis B surface antibody (HBsAb), also known as anti-HBs. This antibody appears in the blood after successful vaccination or recovery from hepatitis B infection, signaling protection against future infection. A positive anti-HBs means the person is immune.

In contrast, the Hepatitis B surface antigen (HBsAg) shows an active infection, not immunity. The core antibody (HBcAb) reflects past or current exposure to the virus but does not by itself prove protective immunity. The e antigen (HBeAg) indicates active viral replication and high infectivity, again not immunity. So the presence of anti-HBs specifically confirms immunity.