This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T., Subject name: Medicine
In a patient only Anti HBsAg is positive in serum, all other viral markers are negative. This indicates 
Select and explain. 
A. Acute hepatitis, B. Chronic active hepatitis, C. Persistent carrier, D. Immunized person with hepatitis B vaccine
D: Immunized person with hepatitis B vaccine
Answer: D: Immunized person with hepatitis B vaccine 
Explanation: Ans. is A i.e Immunized person with hepatitis B vaccine Isolated Anti-HBsAg is seen in - Immunization with HBs AgRemote past infectionFalse positive.