Plasma HBV-DNA and HBsAg were measured frequently during a single infusion of 40 mg Hepex-B™ (A and B, 3 patients respectively), and following multiple infusions of 40 mg (C and D) or 80 mg (E and F). An immediate rapid decline after the beginning of infusion is observed for HBV-DNA and even more pronounced for HBsAg, with the exception of 1 non-responding patient (triangles in C and D). After the end of the infusion, a rebound in viraemia is observed, although it is delayed in some of the patients.