Interpretation of Hepatitis B Serologic Test Results
A reactive Hepatitis B surface antibody (HBsAb), non-reactive Hepatitis B core antibody (HBcAb), and non-reactive Hepatitis B surface antigen (HBsAg) indicates immunity from vaccination rather than from natural infection. 1, 2
Understanding the Serologic Pattern
- This pattern (HBsAb positive, HBcAb negative, HBsAg negative) is definitive evidence of immunity acquired through hepatitis B vaccination 2
- The presence of HBsAb at levels ≥10 mIU/mL indicates protective immunity against hepatitis B virus infection 2
- The absence of HBcAb confirms that the person has never been infected with hepatitis B virus 1, 2
- The absence of HBsAg confirms there is no current hepatitis B infection 1
Clinical Significance
- This serologic pattern represents the ideal outcome of hepatitis B vaccination - successful development of protective antibodies without any history of infection 2
- Immunocompetent individuals with this pattern have long-term protection against hepatitis B infection and do not need further periodic testing to assess antibody levels 1, 2
- This pattern distinguishes vaccine-induced immunity from immunity acquired through natural infection (which would show positive HBcAb) 2, 3
Management Implications
- No further hepatitis B testing or vaccination is needed for immunocompetent individuals with this serologic pattern 1, 2
- If the person becomes significantly immunocompromised in the future, monitoring of antibody levels may be considered, but is not routinely recommended 1
- This serologic pattern confirms successful vaccination and protection against future hepatitis B infection 1, 2
Comparison with Other Serologic Patterns
- Unlike individuals with past resolved infection (HBsAg negative, HBcAb positive, HBsAb positive), those with vaccine-induced immunity have no risk of viral reactivation during immunosuppressive therapy 4, 5
- This pattern differs from chronic infection (HBsAg positive, HBcAb positive, HBsAb negative) 1
- It also differs from the "isolated core antibody" pattern (HBsAg negative, HBcAb positive, HBsAb negative), which can represent resolved infection with waning antibodies, false-positive results, or "occult" HBV infection 1, 6
Pitfalls and Caveats
- Very high HBsAb levels may suggest recent vaccination or robust immune response to previous vaccination 2
- Rarely, false-positive HBsAb results can occur, but the combination of negative HBcAb and negative HBsAg makes this unlikely in this case 7
- It's important to confirm that adequate antibody levels (≥10 mIU/mL) are present for true protection 1, 2