Micro & Immunology · single question
Anti-HBs positive — what does this mean?
Show answer and explanation
Correct answer: B. Vaccinated against Hepatitis B (or recovered with immunity)
- A. ❌ Chronic HBV carrier = HBsAg positive >6 months. Anti-HBs is ABSENT in chronic carriers.
- B. ✅ Correct. Anti-HBs (antibody to HBV surface antigen) is a PROTECTIVE antibody. Positive anti-HBs = (1) successful vaccination, or (2) recovery from past HBV infection with natural immunity.
- C. ❌ Seronegative/susceptible patients have no HBV markers at all.
- D. ❌ Active acute infection = HBsAg positive + anti-HBc IgM positive. Anti-HBs appears only after HBsAg clearance.
Practice Micro & Immunology questions Micro & Immunology study notes