Confirming Hepatitis B Vaccine Immunity
You have immunity to hepatitis B from vaccination if your anti-HBs (hepatitis B surface antibody) level is ≥10 mIU/mL when tested 1–2 months after completing the vaccine series. 1, 2
What Test to Order
Order a quantitative anti-HBs test using an assay such as ELISA that can detect the protective threshold of ≥10 mIU/mL. 1, 2 This single test is sufficient if you have documented completion of the vaccine series and no risk factors for hepatitis B infection. 1
Interpreting Your Results
If anti-HBs ≥10 mIU/mL:
- You are immune and protected. 1, 2, 3
- No further testing or booster doses are needed if you are immunocompetent. 1, 2, 3
- Protection persists for 30+ years and likely for life, even when antibody levels later decline below 10 mIU/mL, because immune memory cells maintain protection. 2, 3
If anti-HBs <10 mIU/mL:
- You are considered a non-responder to the initial vaccine series and susceptible to infection. 1, 3
- Receive one booster dose of hepatitis B vaccine immediately, then retest anti-HBs 1–2 months later. 1, 3
- If anti-HBs remains <10 mIU/mL after the booster, complete a full second 3-dose vaccine series (at 0,1, and 6 months), then retest 1–2 months after the final dose. 1, 3
- After completing 6 total doses, if still non-responsive, test for HBsAg and anti-HBc to rule out chronic hepatitis B infection. 1, 4
Timing of Testing
Test 1–2 months after your final vaccine dose. 1, 2, 3 Testing earlier may show falsely low levels because peak antibody response has not yet occurred. 1 Testing later than 6 months is acceptable but may show naturally declining levels that do not reflect lack of immunity. 1
Special Populations Requiring Testing
Post-vaccination testing is specifically recommended for: 1, 3
- Healthcare workers and public safety personnel with blood/body fluid exposure risk
- Hemodialysis patients
- HIV-infected or immunocompromised persons
- Sexual partners of HBsAg-positive persons
- Infants born to HBsAg-positive mothers
Common Pitfalls
Do not confuse different hepatitis B tests. 2, 3 The three main markers are:
- Anti-HBs (hepatitis B surface antibody): Indicates immunity from vaccination or past infection
- HBsAg (hepatitis B surface antigen): Indicates current infection
- Anti-HBc (hepatitis B core antibody): Indicates past or current infection, but NOT present after vaccination alone
A pattern of anti-HBs positive + HBsAg negative + anti-HBc negative confirms vaccine-derived immunity. 3 If you only have anti-HBs positive, you are immune from vaccination. 3
Do not retest or get boosters if you are immunocompetent and initially responded with anti-HBs ≥10 mIU/mL. 2, 3 Even if your antibody level later drops below 10 mIU/mL, you remain protected through immune memory. 2, 3
Immunocompromised Patients
If you are immunocompromised (HIV infection, chemotherapy, hemodialysis, transplant recipient), you require: 1, 2, 3