Hepatitis B Serology After Vaccination
Postvaccination serologic testing is not necessary for most vaccinated patients, but is specifically required for healthcare personnel, immunocompromised individuals, hemodialysis patients, and sexual/needle-sharing partners of HBsAg-positive persons. 1
General Population: No Testing Required
- Routine serologic testing for immunity is unnecessary after standard vaccination of infants, children, or adolescents. 1
- Immunocompetent adults who complete the vaccine series do not require postvaccination testing. 1
- Immunologic memory persists even when antibody levels decline below 10 mIU/mL, providing ongoing protection through rapid anamnestic responses upon exposure. 2, 3
- Vaccinated immunocompetent persons have long-term protection and do not need periodic anti-HBs testing. 1
High-Risk Groups Requiring Postvaccination Testing
Testing for anti-HBs should be performed 1-2 months after the final vaccine dose for the following groups: 1
- Healthcare personnel and public safety workers at risk for blood or body fluid exposure 1
- Hemodialysis patients and those who might require outpatient hemodialysis 1
- HIV-infected persons and other immunocompromised individuals (e.g., hematopoietic stem-cell transplant recipients, persons receiving chemotherapy) 1
- Sexual and needle-sharing partners of HBsAg-positive persons 1
- Infants born to HBsAg-positive mothers 1
Testing Methodology and Interpretation
- Use a quantitative method (e.g., ELISA) that detects protective anti-HBs concentrations ≥10 mIU/mL. 1
- Anti-HBs ≥10 mIU/mL indicates immunity and protection. 1
- Persons with anti-HBs <10 mIU/mL after the primary series should be revaccinated with a complete 3-dose series, followed by repeat testing 1-2 months after the final dose. 1
Special Consideration: Healthcare Personnel Vaccinated in Childhood
For healthcare personnel who received routine vaccination as infants or adolescents without postvaccination testing, institutions may measure anti-HBs upon hire or matriculation. 1, 4
- Because vaccine-induced antibody wanes over time, testing years after vaccination may not distinguish true nonresponders from responders. 1
- If anti-HBs <10 mIU/mL is found, administer one booster dose and retest 1-2 months later. 1, 5
- If anti-HBs remains <10 mIU/mL after the booster, complete a second full 3-dose series and retest. 1, 5
- Alternatively, institutions may defer testing until the time of an actual occupational exposure, though this requires reliable exposure reporting systems. 1
Common Pitfalls to Avoid
- Do not test anti-HBs in routine immunocompetent vaccinees years after vaccination—this creates unnecessary concern when antibody levels have naturally waned despite persistent immune memory. 1, 6, 2
- Do not restart the entire vaccine series for persons with low or undetectable antibodies—give a single booster dose first. 5
- Do not delay vaccination while waiting for serologic test results in at-risk individuals. 1, 5
- Do not assume lack of detectable antibody means lack of protection in immunocompetent persons—cellular immunity and memory B cells persist. 6, 2, 7
Ongoing Monitoring Requirements
- Immunocompromised persons may need annual anti-HBs testing to assess antibody concentrations. 1
- Hemodialysis patients require annual anti-HBs testing, with booster doses when levels decline to <10 mIU/mL. 1
- Immunocompetent persons with documented protective response do not need further periodic testing. 1, 6