The serum of an individual who completed all doses of the hepatitis B vaccine should contain which antibody?

• A. anti-HBs
• B. anti-HBe
• C. anti-HBc
• D. all of the above

Answer: (A)

The key idea is that the hepatitis B vaccine contains only the surface antigen (HBsAg). This stimulates the immune system to produce antibodies against the surface antigen—anti-HBs—which provides protective immunity. The vaccine does not include the core antigen (HBc) or the e antigen (HBe), so antibodies to those components (anti-HBc and anti-HBe) are not generated by vaccination. Therefore, after completing the vaccine series, the serum should show anti-HBs antibodies, indicating immunity. In contrast, anti-HBc would suggest prior infection with hepatitis B, and anti-HBe is associated with active viral replication during infection, not vaccination.