Recombinant Hepatitis B Vaccine Adjuvanted With AS04 in Dialysis Patients: A Prospective Cohort Study.

BACKGROUND/AIMS Patients undergoing maintenance dialysis have an unsatisfactory response to vaccination, including to hepatitis B vaccine. A recombinant HB vaccine containing a new adjuvant system AS04 (HBV-AS04) has been recently developed; a few data exist on the immunogenicity and safety of HBV-AS04 among patients undergoing regular dialysis. All hepatitis B virus-seronegative patients with undetectable antibody against HBsAg undergoing maintenance dialysis at two units were prospectively included. METHODS Patients received four 20-mcg doses of HBV-AS04 by intramuscular route (deltoid muscle) at months 0,1,2, and 3. Anti-HB surface antibody concentrations were measured at intervals of 1, 2, 3, 4, and 12 months. Univariate and multivariate analyses determined which parameters predicted immunologic response to HBV-AS04 vaccine. RESULTS 102 patients were enrolled and 91 completed the study. At completion of the vaccination schedule, using per-protocol analysis, 76 of 91 (84%) had antibody titers ≥10 mIU/mL with anti-HBs geometric antibody concentrations (GMCs) of 385.25 mIU/mL. The sero-protection rate at month 12 was 84% (48/57) with lower GMCs (62.74 mIU/mL, P<0.0001). Multivariate analysis revealed a detrimental role of age on the immune response to HB-AS04 vaccine (F Ratio, 4.04; P<0.04). Tolerance to HBV-AS04 was good and only minor side-effects were observed. CONCLUSIONS HBV-AS04 vaccine was highly immunogenic in our cohort of patients on maintenance dialysis even if a significant number of non-responders is still present. Prospective studies with HBV-AS04 on larger study groups and with longer follow-ups are under way.