Hepatitis B Immunity Testing
Order a hepatitis B surface antibody (anti-HBs) test using a quantitative method to check for hepatitis B immunity. 1
Standard Test for Immunity Assessment
Anti-HBs is the single test needed to assess immunity in previously vaccinated individuals, particularly healthcare personnel, hemodialysis patients, and other high-risk groups requiring documentation of protection. 1
The test must be quantitative (not qualitative) to allow determination of protective antibody concentrations, with ≥10 mIU/mL considered seroprotective. 1
Testing should be performed 1-2 months after the final vaccine dose when assessing post-vaccination immunity. 1
When to Order Additional Tests
For prevaccination screening (not immunity checking), the Advisory Committee on Immunization Practices recommends a three-test panel:
- HBsAg (hepatitis B surface antigen) - identifies active infection 1, 2
- Anti-HBs (hepatitis B surface antibody) - indicates immunity 1, 2
- Total anti-HBc (hepatitis B core antibody) - distinguishes natural infection from vaccine-induced immunity 1, 2
This comprehensive panel is recommended for specific populations before vaccination, including household/sexual contacts of HBsAg-positive persons, HIV-positive individuals, persons who inject drugs, men who have sex with men, hemodialysis patients, and persons born in countries with HBV prevalence ≥2%. 1
Clinical Interpretation
Anti-HBs ≥10 mIU/mL = immune, no further action needed in immunocompetent persons 1
Anti-HBs <10 mIU/mL = non-immune, requires revaccination with additional doses followed by repeat testing 1
Immunocompromised patients (HIV-infected, transplant recipients, chemotherapy patients) may need annual anti-HBs testing to assess ongoing protection 1
Important Caveats
Different assays have different cutoff values - always refer to the specific test's package insert for accurate interpretation of protective levels. 1
Immunocompetent persons with documented vaccine response do not need routine booster testing - cellular immune memory provides long-term protection even if antibody levels decline below 10 mIU/mL. 1, 3
Hemodialysis patients are the exception - they require annual anti-HBs testing with booster doses when levels fall below 10 mIU/mL. 1