Serum or plasma substance concentration for a specific antibody related to hepatitis B virus immunity (anti-HBs)
This test measures the presence of antibodies in your blood that help your immune system fight hepatitis B virus infection. It can indicate whether you’ve had hepatitis B, received a vaccine, or are immune due to prior exposure.
["Anti-HBs helps determine immunity status against hepatitis B, guiding vaccination decisions or monitoring recovery from infection."]
Key facts at a glance
- LOINC
- 44539-5
- Short code
- HTLV II Ab Ser Ql IA
- Synonyms
- HTLV II Ab Ser Ql IA
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may order this test if you’ve had hepatitis B vaccination, suspect exposure to hepatitis B, or need to check if your immune system is protecting you from the virus. It’s also used to monitor people who’ve recovered from hepatitis B or those with chronic infection.
What to Expect Before the Test
No special preparation is needed. A small needle will draw blood from a vein in your arm. You may feel slight discomfort, but it usually lasts only a few seconds. If you’re on blood thinners, let your provider know before the test.
What the Results Mean
Results can be positive (meaning your body produced antibodies to hepatitis B) or negative (meaning no detectable antibodies). A positive result suggests immunity, while a negative result may mean you need vaccination or further testing. Always discuss results with your doctor.
Common Reasons for Testing
This test is often used to confirm immunity after vaccination, check for past infection, or evaluate immune response in people at higher risk of hepatitis B (e.g., healthcare workers, travelers to endemic regions).
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive anti-HBs result indicates immunity and protection against hepatitis B. A negative result may prompt vaccination or further testing for hepatitis B surface antigen (HBsAg), which confirms active infection. It’s critical for preventing spread of the virus and managing long-term health risks.
Short name
Hepatitis B surface antibody (anti-HBs)
Frequently asked questions
What does a positive anti-HBs result mean?
Can a negative anti-HBs result mean I’m still at risk?
How long does it take to get results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy