Antibodies after hepatitis B vaccine (anti-HBs)
anti-HBs · hepatitis B surface antibody · hepatitis B immunity test · hep B titer
This blood test shows how many protective antibodies to hepatitis B you have after the vaccine.
For health workers, people on dialysis, family of people with hepatitis B, and people with a weak immune system, to see if the vaccine worked.
⏱ Duration: the blood draw takes a few minutes; results usually come in 1 to 3 days
Be sure to tell your doctor
How to prepare
- Timing. The test is usually done 1 to 2 months after the last shot in the series. Ask your doctor.
- Food. You usually do not need to fast strictly, but it is better to come 3 to 4 hours after a light, non-fatty meal. Check with the lab.
- Clothing. A sleeve you can easily roll up above the elbow.
What to bring
- Your referral or list of tests
- Your ID
- Your vaccination certificate or records
How it goes
- You sit down and rest your arm on the armrest
- A band is tied above your elbow, and you are asked to clench your fist a few times
- The skin is wiped with antiseptic
- A quick prick. Blood fills the tubes in a few seconds
- The needle comes out, and a cotton pad is pressed on the spot
What you'll feel
- A quick prick, like a pinch
- Sometimes slight dizziness. Tell the nurse, and they will help you lie down
Afterwards
- Press the cotton pad for 3 to 5 minutes
- If antibodies are low, the doctor may offer another shot
- Keep the result with your vaccination records
Contact a doctor straight away if
- The puncture site is very swollen, painful, and red
Common questions
What level counts as protection?
The lab form shows the protection threshold. If your result is above it, the vaccine worked.
Does everyone need an antibody check after the vaccine?
No. It is usually checked in people at high risk of infection. Your doctor will advise.