Hepatitis B surface antibody (anti-HBs)

Hepatitis B surface antibody (anti-HBs) is a protective immunoglobulin produced by the host immune system in response to the Hepatitis B surface antigen (HBsAg), either following natural infection or vaccination (CDC, 2023). Its primary biological function is the neutralization of the Hepatitis B virus (HBV) by binding to the HBsAg on the viral envelope, which prevents the virus from attaching to and entering host hepatocytes (StatPearls, 2023). In the context of disease, the presence of anti-HBs is a critical indicator of immunity and the resolution of acute infection, with titers above 10 mIU/mL generally considered to provide long-term protection against reinfection (WHO, 2022). While anti-HBs is not a therapeutic target for small molecule drugs, it is utilized as a therapeutic agent itself in the form of Hepatitis B Immune Globulin (HBIG) for post-exposure prophylaxis and to prevent HBV recurrence in liver transplant recipients (Mayo Clinic, 2023). Furthermore, the induction of anti-HBs is the primary goal of Hepatitis B vaccines, which utilize recombinant HBsAg to stimulate a protective immune response (NIH, 2023). Monitoring anti-HBs levels is essential for clinical decision-making regarding vaccination schedules and assessing the immune status of high-risk populations.

Other names

HBsAbAntibody to Hepatitis B surface antigenanti-HBsAgHepatitis B virus surface antibody

Neutralization of Hepatitis B virus (HBV) by binding to the surface antigen (HBsAg) on the viral envelope, which prevents viral attachment to the sodium taurocholate cotransporting polypeptide (NTCP) receptor on hepatocytes and facilitates viral clearance (StatPearls, 2023).