Which serology pattern indicates immunity to hepatitis B due to vaccination?

• A. HBsAg positive
• B. Anti-HBs positive and anti-HBc negative
• C. Anti-HBs negative and anti-HBc positive
• D. HBsAg negative and anti-HBs negative

Answer: (B)

Immunity from hepatitis B vaccination shows up in serology as anti-HBs antibodies present while anti-HBc antibodies are absent. The vaccine contains only the surface antigen (HBsAg), so it triggers protective anti-HBs without exposing the core antigen. That makes the pattern of anti-HBs positive and anti-HBc negative the best indicator of vaccine-induced immunity (and typically HBsAg negative as well, since there’s no infection). This differs from natural infection, where anti-HBc would usually be present, reflecting exposure to the core antigen.