Hepatitis B challenge dose in vaccinated healthcare personnel susceptible at hire

Due to the nature of their work, healthcare personnel are at an increased risk for hepatitis B infection, and some may not respond fully to the vaccine. Many health systems evaluate hepatitis B vaccine response of new employees with history of vaccines series completion at time of hire. Individuals found to have hepatitis B antibodies (anti-HBs) that are negative, or borderline (non-immune) may receive a challenge dose. Hepatitis B vaccine with CpG adjuvant (hepB-CpG) has shown higher response rates compared to hepatitis B vaccine with aluminum adjuvants (hepB-Alum) in many populations. The aim of this study is to determine if individuals with negative or borderline (non-immune) levels of anti-HBs at time of hire, despite previous vaccination, are more likely to respond to hepB-CpG or hepB-Alum challenge dose. For an individual to be considered eligible, the following criteria must be met: (1) history of hepB-Alum series completion, (2) anti-HBs assay that are negative or borderline (non-immune) at hire, (3) received challenge dose (hepB-CpG or hepB-Alum), (4) had post-challenge dose antiHBs measured. Of immunized individuals who were anti-HBs negative or borderline (non-immune) at hire, 1020/1049 (97.2%) responded to the hepB-CpG challenge dose compared to 877/1006 (87.2%) who responded to the hepB-Alum challenge dose (p < 0.001). Among those who received hepB-CpG challenge dose, those whose primary series was the pediatric preparation were more likely to respond to the challenge dose compared to those who receive the adult vaccine preparation as their primary series. (pediatric 959/983 (97.6%) vs adult 62/67 (93.5%) p = 0.033), but no hepB-Alum response rate difference was found for pediatric vs adult primary series. HepB-CpG challenge dose was associated with a higher response rate compared to hepB-Alum challenge dose and should be considered the preferred vaccine preparation for this situation.