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Micro & Immunology · single question

Anti-HBs positive — what does this mean?

  1. Chronic Hepatitis B carrier
  2. Vaccinated against Hepatitis B (or recovered with immunity)
  3. Seronegative — susceptible to HBV
  4. Active acute Hepatitis B infection
Show answer and explanation

Correct answer: A. Chronic Hepatitis B carrier

  • A. 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.
  • B. Incorrect. Active acute infection = HBsAg positive + anti-HBc IgM positive. Anti-HBs appears only after HBsAg clearance.
  • C. Incorrect. Chronic HBV carrier = HBsAg positive >6 months. Anti-HBs is ABSENT in chronic carriers.
  • D. Incorrect. Seronegative/susceptible patients have no HBV markers at all.

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