The Hepatitis B Surface Antibody (Anti-HBs) Test detects antibodies against the Hepatitis B Surface Antigen (HBsAg). This test is used to determine if a person is immune to Hepatitis B due to vaccination or past infection.
✅ Checks Immunity After Vaccination – Determines if the HBV vaccine was effective.
✅ Confirms Recovery from HBV Infection – A positive result indicates natural immunity.
✅ Helps Decide if Vaccination is Needed – People with a negative result may need the HBV vaccine.
✅ Evaluates Need for Post-Exposure Prophylaxis (PEP) – After possible exposure to HBV.
🩸 Blood Sample Collection – A blood sample is taken and analyzed using ELISA (Enzyme-Linked Immunosorbent Assay) or Chemiluminescent Immunoassay (CLIA).
| Anti-HBs Result | Interpretation | Next Steps |
|---|---|---|
| Positive (≥10 mIU/mL) | Immune to HBV (from vaccination or past infection) | No further action needed. |
| Negative (<10 mIU/mL) | Not immune to HBV | Vaccination recommended. |
📌 If Anti-HBs is positive and HBsAg is negative, the person is protected and NOT infected.
| Condition | HBsAg | Anti-HBc | Anti-HBs |
|---|---|---|---|
| Vaccinated Against HBV | Negative | Negative | Positive |
| Recovered from HBV Infection | Negative | Positive | Positive |
| Chronic HBV Infection | Positive | Positive | Negative |
| Susceptible to HBV (No Immunity) | Negative | Negative | Negative |
✔ People who have received the HBV vaccine (to confirm immunity).
✔ Healthcare workers (to ensure protection from HBV).
✔ Individuals exposed to HBV (to assess need for post-exposure prophylaxis).
✔ Patients with chronic liver disease (to evaluate HBV immunity status).
✔ Individuals planning immunosuppressive therapy (to assess risk of HBV reactivation).
✔ A positive Anti-HBs test means you are protected from HBV.
✔ Vaccination provides lifelong protection if Anti-HBs is ≥10 mIU/mL.
✔ A negative Anti-HBs test means vaccination may be needed.
✔ People who recovered from past infection will have both Anti-HBs and Anti-HBc positive.