Serologic hepatitis B immunity in vaccinated health care workers

Background: Hepatitis B vaccination is recommended for health care workers but has a nonresponse rate of 5% to 32% and an unknown duration of immunity . There is no standardized postvaccination protocol to confirm, monitor, an d maintain immunity. Objective: To assess the hepatitis B serologic immune status in health care workers who were previously vaccinated. Methods: A convenience survey and an objective laboratory study, which incl uded testing for hepatitis B surface antigen, core antibody, and qualitativ e and quantitative surface antibody (anti-HBs), were performed. The data co llected included vaccination date, number of doses of vaccine, whether and when titers had previously been checked, titer results, sex of patient, job description, and age at the time of our study and at vaccination. Results: Group A (n = 109, 71%) had detectable anti-HBs titers, and group B (n = 45, 29%) had no detectable anti-HBs titers. Group A was vaccinated 4. 80 +/- 0.30 (mean +/- SEM) years prior to our testing, received 2.91 +/- 0. 04 (mean +/- SEM) vaccinations, and had a mean +/- SEM titer Of 112.91 +/- 5.18 mIU/mL. There was no statistical significance in time since vaccinatio n, number of doses of vaccine, sex, job description, age at the time of our serologic testing, or age at the time of vaccination between groups A and B. Six of 6 subjects given booster doses of vaccine in group B developed an ti-HBs. Only 62 subjects (40%) in the entire study population had anti-HBs status previously determined, with 48 (77%) reporting immunity to hepatitis B virus. Conclusions: Twenty-nine percent of the health care workers who were vaccin ated against hepatitis B showed no serologic evidence of hepatitis B immuni ty. It is unclear whether these subjects are nonresponders, lost immunity, or retained anamnestic potential. Booster vaccination response in 6 of 6 su bjects suggests immunity. We recommend (1) postvaccination testing within 1 to 2 months to document immunity, (2) periodic anti-HBs monitoring, and (3 ) booster vaccination to maintain protective titer levels.