Long-term hepatitis B immunoglobulin (HBIg) prophylaxis prevents endogenous hepatitis B virus (HBV) reinfection in the majority of liver transplant recipients. Active hepatitis B vaccination after orthotopic liver transplantation (OLT) in these patients has produced conflicting results to date. On this study, patients who remained hepatitis B surface antigen (HBsAg) negative with passive immunization after OLT for HBV cirrhosis were actively immunized using recombinant HBV antigen (Engerix), together with a novel adjuvant system (monophosphoryl lipid A and a natural saponine molecule). This led to a sustained antibody response to HBsAg (>500 IU/L) in 5 of 10 patients. This antibody response prevented reinfection and allowed termination of prophylactic HBIg substitution for more than 12 months in these patients.