Human rabies immune globulin. Clinical trials and effects on serum anti- -globulins

Human-derived rabies immune globulin (HRIG) was administered intramuscularly to 24 male volunteers according to two dose schedules: either 20 ml (equivalent to the World Health Organization [WHO] recommendation of 40 internation units/kg for equine-derived antiserum) or one-fourth of the WHO recommendation (10 IU/kg). The 10-IU/kg dose gave barely detectable antirabies antibody titers and is not considered of therapeutic value. The 20-ml dose gave higher, longer lasting titers of antirabies antibody than the comparable doses of equine antiserum currently in use. There were no untoward reactions. Before administration of HRIG, all 24 volunteers had IgG class anti-IgG antibodies (mean titer, 114μg/ml); 22 of 24 had IgA class anti-IgG antibodies (mean titer, 65μg/ml); and none of the 24 had IgM class anti-IgG antibodies. Administration of HRIG caused no significant change in these titers.