Background:  Hepatitis B virus (HBV) vaccination has been recommended to reduce risk of HBV infection for persons at risk for HIV and HBV transmission. However, the effect of a nationwide HBV vaccination program on the prevalence of HBV infection and factors associated with maintaining protective anti-HBs antibody (≥10 mIU/mL) remain unknown among HIV-infected persons.
Methods:  Between 2004 and 2007, we enrolled 4056 HIV-infected persons aged ≥15 years and 2594 HIV-uninfected persons (control group). Prevalence of hepatitis B surface antigen (HBsAg), anti-HBs, anti-HBc, and anti-HCV antibody were compared between the 2 groups and between persons born before and after nationwide HBV vaccination program and several catch-up vaccination programs for newborns and children were implemented in Taiwan. Titers of anti-HBs antibody were compared between 207 HIV-infected persons and 161 controls who had undergone HBV vaccination. Determination of anti-HBs antibody titers was performed with the use of radioimmunoassay.

Results:  Overall prevalence of HBsAg was 19.8% and 20.8% for HIV-infected heterosexuals or men who have sex with men and intravenous drug users (IDU), respectively (p = 0.53), which was significantly higher than that of controls (13.2%) (p <0.001). However, no differences were observed in prevalence of HBsAg (5.9% vs 8.5%, p = 0.82) or anti-HBc antibody (39.1% vs 27.9%, p = 0.24) between IDU and controls who were born after vaccination program was launched. The proportion of persons with anti-HBs titers ≥10 and >100 mIU/mL was significantly higher among HIV-infected HBV vaccinees than among controls:  67.1% vs 45.3% (p <0.001) and 40.1% vs 12.4% (p <0.001), respectively. In multivariate analysis, factors associated with maintaining protective anti-HBs titers were HIV-infected HBV vaccinees who were born after 1980 compared with those born before 1980 (OR 3.746, 95%CI 1.567 to 8.957) and persons with baseline CD4 counts ≥350 cells/μL compared with those with CD4 count<350 cells/μL (OR 2.478, 95%CI 1.099 to 5.586).

Conclusions:  Nationwide HBV vaccination for newborns and children in Taiwan has been associated with significant reduction of HBV infection among HIV-infected persons who had undergone HBV vaccination before HIV infection. Maintaining higher levels of protective anti-HBs titers was more common among the HIV-infected HBV vaccinees with better immune status than HIV-uninfected controls.