Interpret Your Hepatitis B Surface Antibody Results
Enter your Anti-HBs value below and get an instant, free AI interpretation — a plain-English explanation checked against WHO/IFCC reference ranges.
Medical Disclaimer
This AI-generated interpretation is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Results may vary based on individual health factors not captured here.
Always consult a qualified healthcare professional before making any health decisions. Read full disclaimer →
Hepatitis B Surface Antibody Normal Ranges
Anti-HBs (Hepatitis B Surface Antibody) indicates immunity to Hepatitis B — either from successful vaccination or from natural recovery after infection.
| Reference Range | Unit | Notes |
|---|---|---|
| 10 – 999 | IU/L | Protective ≥10 IU/L |
Also reported in: mIU/mL.
Why Doctors Order the Hepatitis B Surface Antibody Test
Anti-HBs is measured to confirm adequate immune response after HBV vaccination, especially in high-risk groups (healthcare workers, dialysis patients, immunocompromised individuals). Response rates to the standard 3-dose HBV vaccine series are >90% in healthy adults under 40, declining with age and immunosuppression.
How to Enter Your Anti-HBs Result
Hepatitis B Surface Antibody can be reported in IU/L or mIU/mL. Choose the unit printed next to your result on the lab report so it is compared with the matching reference range.
What a Low or High Anti-HBs Can Be Associated With
Below the reference range
- Non-response to HBV vaccine (<10 IU/L) — occurs in ~5–10% of healthy adults
- Waning immunity years after vaccination (levels decline over time)
- Immunosuppression reducing vaccine response (HIV, renal failure, chemotherapy)
- Genetic non-responders (rare HLA-related inability to mount anti-HBs response)
Above the reference range
- Successful Hepatitis B vaccination (most common)
- Natural recovery from acute Hepatitis B infection (Anti-HBs develops alongside Anti-HBc)
These are common associations, not a diagnosis. A single result is read alongside your symptoms, history and other tests — discuss it with your doctor.
What Can Change Your Anti-HBs Result
Before you read too much into a result, consider whether any of these applied:
- Anti-HBs measured within days of an HBV vaccination dose may reflect passive transfer rather than immune response
- Recent HBIG (Hepatitis B Immunoglobulin) administration transiently raises Anti-HBs without true immunization
Preparing for the test: No fasting required. For best assessment of vaccine response, measure Anti-HBs 4–8 weeks after completing the vaccine series.
Symptoms That Often Prompt Anti-HBs Testing
- Anti-HBs itself causes no symptoms — it is a protective antibody
- Low Anti-HBs indicates susceptibility to Hepatitis B infection
Want the full clinical guide to Hepatitis B Surface Antibody?
Reference ranges, causes, symptoms, preparation, and FAQs.