What does a positive hepatitis B surface antibody mean?

If the test results show that the hepatitis B surface antibody is positive, it means that the body has the ability to resist the hepatitis B virus, and the higher the quantity of the hepatitis B surface antibody, the stronger the protection it will produce. The positive status of hepatitis B surface antibody does not completely mean that the patient will not develop viral hepatitis, so everyone should also take preventive measures.

Hepatitis B surface antibody is an immune and protective antibody against the hepatitis B virus. Its positivity indicates that the person has been infected with the hepatitis B virus in the past but the virus has been eliminated, or that the person has been vaccinated with the hepatitis B vaccine and has produced protective antibodies. The higher the hepatitis B surface antibody titer in the serum, the stronger the protection. However, there are a small number of people who are positive for hepatitis B surface antibodies and yet develop hepatitis B. This may be due to infection with a different subtype or a mutation of the hepatitis B virus.

The positive appearance of hepatitis B surface antibody means that among the five hepatitis B serum markers, the antigen is a component of the virus itself, while the antibody is a product of the body's immune response, and their clinical significance is different. Hepatitis B surface antibody (anti-HBs) is a protective antibody that often appears positive in the late stage of infection recovery, when the hepatitis B surface antigen (HBsAg) has turned negative for at least 1 month. Anti-HBs reaches its peak in June-December, then gradually decreases and turns negative within 10 years (sometimes it turns negative very quickly).

Appearance time

The early or late appearance of hepatitis B surface antibodies is related to whether the person has been infected with the hepatitis B virus in the past. The onset of symptoms is slower in people who are first infected with hepatitis B virus, and earlier in those who are reinfected. In most cases, surface antibodies appear 4 to 5 months after infection with the hepatitis B virus, but the titer is not high and gradually disappears after 0.5 to 3 years. In those who are reinfected, hepatitis B surface antibody can generally be detected within 2 weeks, and the titer is relatively high.