Hepatitis B vaccination and risk of hepatitis B infection in HIV-infected individuals

Objective: To assess the association of hepatitis B virus (HBV) vaccination with risk of HBV infection among HIV-infected patients and HBV infection risk factors among vaccinees. Design: Observational cohort study. Methods: Participants enrolled from 1986 through 2004, unvaccinated and serologically negative for HBV infection at the time of HIV diagnosis, were followed longitudinally through 2007 for the occurrence of HBV infection. Risk factors for HBV infection were evaluated using time to event methods, including Kaplan-Meier survival curves and Cox proportional hazards models. Results: During 11 632 person-years of follow-up, the rate of HBV infection was 2.01 (95% CI 1.75-2.27)/100 person-years. Receipt of at least one dose of vaccine was not associated with reduced risk of HBV (unadjusted hazard ratio 0.86, 95% CI 0.7-1.1; adjusted hazard ratio 1.08, 95% CI 0.8-1.4). Receipt of three or more doses of vaccine was also not associated with reduced risk (hazard ratio 0.96; 95% CI 0.56-1.64). Among 409 vaccinees with HBsAb less than 10 IU/l, 46 (11.2%) developed HBV infection compared with 11 of 217 (5.1%) vaccinees with HBsAb 10 IU/l (hazard ratio 0.51; 95% CI 0.3-1.0). In participants with initial HBsAb less than 10 IU/l, 16 of 46 (35%) infections were chronic, compared with none of 11 in those with initial HBsAb at least 10 IU/l (P = 0.02). Conclusion: Overall, HBV vaccination was not associated with reduced risk of HBV infection in our cohort of HIV-infected individuals. However, the small subset of vaccinees with a positive vaccine response may have had reduced HBV infection risk, including chronic disease. Improvements in vaccine delivery and immunogenicity are needed to increase HBV vaccine effectiveness in HIV-infected patients.