HBsAg tells us:

HBsAg tells us:

• A. Immunity
• B. Acute or chronic infection ( if positive chronic hep b)
• C. Resolved infection
• D. Carrier status only

Answer: (B)

HBsAg is a marker of active hepatitis B infection. When this antigen is detectable in the blood, the person currently has hepatitis B, and the infection can be either acute or chronic. If HBsAg stays positive for more than about six months, the infection is considered chronic. This marker does not indicate immunity—that role belongs to anti-HBs antibodies after vaccination or recovery. It also doesn’t signify a resolved infection, which would typically show no HBsAg and presence of anti-HBs. While chronic carriers often have ongoing HBsAg positivity, the key point is that this test signals current infection, not just carrier status or immunity.

HBsAg is a marker of active hepatitis B infection. When this antigen is detectable in the blood, the person currently has hepatitis B, and the infection can be either acute or chronic. If HBsAg stays positive for more than about six months, the infection is considered chronic. This marker does not indicate immunity—that role belongs to anti-HBs antibodies after vaccination or recovery. It also doesn’t signify a resolved infection, which would typically show no HBsAg and presence of anti-HBs. While chronic carriers often have ongoing HBsAg positivity, the key point is that this test signals current infection, not just carrier status or immunity.