When to Perform Hepatitis B Titer Testing
Hepatitis B antibody (anti-HBs) testing should be performed 1–2 months after completing the primary vaccine series or after any booster dose to document immune response and guide future management. 1, 2
Routine Post-Vaccination Testing
After Primary Vaccination Series
- Test anti-HBs levels 1–2 months after the final dose of the primary vaccine series to document protective immunity (≥10 mIU/mL) for future reference 1, 2
- Use a quantitative assay (e.g., ELISA) that can detect the protective threshold of ≥10 mIU/mL 2
- This timing applies universally across all populations completing the standard vaccination schedule 2
After Booster Doses
- Recheck anti-HBs 1–2 months after any booster dose to assess immune response 2, 3
- If a second complete vaccine series is administered (for non-responders), test 1–2 months after the final dose of that series 1
Special Circumstances Requiring Modified Timing
When HBIG Was Administered
- Wait 4–6 months after HBIG administration before testing anti-HBs levels, as passively acquired antibodies from HBIG interfere with accurate assessment of vaccine-induced immunity 1, 2
- Testing earlier will yield falsely elevated results that don't reflect true vaccine response 2
Healthcare Personnel After Occupational Exposure
- Test immediately after exposure (baseline) if the healthcare worker has anti-HBs <10 mIU/mL or unknown vaccination status 1
- Baseline testing should include total anti-HBc 1
- Follow-up testing at 6 months should include HBsAg and total anti-HBc 1
High-Risk Populations Requiring Ongoing Surveillance
Hemodialysis Patients
- Perform annual anti-HBs testing regardless of initial response 3, 4
- Administer a booster dose when anti-HBs levels decline below 10 mIU/mL 3
- These patients may lose naturally acquired immunity over time and require closer monitoring 4
Immunocompromised Individuals
- Consider annual anti-HBs testing if ongoing risk for exposure exists 3
- Administer boosters when levels fall below 10 mIU/mL 3, 5
- This includes patients after liver transplantation who require regular serological monitoring 5
Healthcare Workers at Ongoing Risk
- Test anti-HBs levels if vaccination history is undocumented or if post-vaccination testing was never performed 3, 6
- For those with documented anti-HBs <10 mIU/mL, administer one booster dose and retest 1–2 months later 3
- If still <10 mIU/mL after the booster, complete a second 3-dose series and retest 3
When Testing Is NOT Necessary
Immunocompetent Individuals with Documented Response
- Do not perform routine periodic testing in healthy individuals who achieved anti-HBs ≥10 mIU/mL after primary vaccination 1, 5
- Immune memory persists even when antibody levels decline below detectable levels 3, 5, 7
- Long-term protection is maintained through cellular immune memory, not circulating antibody levels 3, 5
Unvaccinated or Incompletely Vaccinated Persons
- Do not test anti-HBs in unvaccinated or incompletely vaccinated individuals, as the protective threshold of ≥10 mIU/mL has only been validated for those who completed an approved vaccination series 1
- Testing in this population is potentially misleading 1
Common Pitfalls to Avoid
- Testing too early (before 4 weeks) may underestimate peak antibody response and miss true immunity 2
- Forgetting HBIG interference can yield falsely elevated results that don't reflect vaccine-induced immunity 1, 2
- Using qualitative tests instead of quantitative assays prevents confirmation of the protective threshold 2
- Administering unnecessary boosters to healthy immunocompetent individuals who completed the primary series wastes resources and is not evidence-based 3
- Relying solely on antibody levels in immunocompetent individuals ignores the persistence of immune memory even when anti-HBs is undetectable 3, 5
- Overlooking post-vaccination testing in high-risk groups (healthcare workers, hemodialysis patients, immunocompromised individuals) fails to document initial response for future management 3