A person has a positive Hepatitis B surface and core antibodies but is negative for the surface antigen. What does this indicate?

A positive result for Hepatitis B surface antibodies (anti-HBs) and core antibodies (anti-HBc) combined with a negative result for the Hepatitis B surface antigen (HBsAg) indicates that the individual has immunity from natural infection. This scenario typically arises when a person has cleared a previous Hepatitis B infection and their immune system has successfully responded by producing antibodies.

In the context of Hepatitis B, the surface antigen represents active viral infection, while the antibodies—especially the surface antibodies—indicate that the person has developed immunity. The presence of core antibodies suggests that there was a previous infection, as these antibodies are produced during the infection episode. Since the surface antigen is negative, it shows that there is no ongoing infection, reinforcing the conclusion of past infection and subsequent immunity.

The other possibilities, like chronic or acute Hepatitis B infection, would typically show as positive for HBsAg, indicating an active viral presence. Immunity from vaccination would present with positive surface antibodies but would not include the core antibodies, indicating that the person did not have a previous infection. Therefore, the presence of both anti-HBs and anti-HBc, along with the negativity for HBsAg, confirms natural immunity from a past infection.