Background HIV patients are at a higher risk of hepatitis B virus (HBV) infection than general population. The aim of this study is to assess the immunogenicity of inactivated hepatitis B vaccine among HIV infected patients.

Methods A total of 536 HIV infected patients from a university hospital in Barcelona who were vaccinated against HBV between 1996 and 2009 were analysed. Anti-HBs titles were evaluated after the last hepatitis B dose for each patient. Multivariate logistic regression was conducted to identify independent factors (sex, age, hepatitis C coinfection, HIV viral load, CD4 count, type of schedule, dose and number of vaccines) associated with vaccine response.

Results About 71% of the vaccinated HIV population were respondents (Anti-HBs antibodies ≥10 IU/l). Vaccine recipients receiving <3 doses (OR 0.29, 95% CI 0.16 to 0.52) and performing an accelerated schedule (0, 7, 21 days and booster dose at month 6) (OR 2.10, 95% CI 1.02 to 3.22) were factors associated with a decreased likelihood of a positive response. Development of anti-HBs was higher in patients with CD4 count ≥350 cells/μl (OR 1.78, 95% CI 1.37 to 2.94), HIV-RNA <50 copies/ml (OR 2.13, 95% CI 1.41 to 3.22) and 40 μg dose schedule (OR 1.82, 95% CI 1.14 to 2.94).

Conclusions These findings show that a 40 μg dose schedule and earlier vaccination from HIV diagnose may be effective strategies for an increased HBV response among HIV infected patients. Anti-HBs titles should be assessed after an accelerated vaccination schedule and after any schedule in patients who present a viral load <50 copies/ml or CD4 count <350 cells/μl, given the low likelihood of response.