Human Rabies Immune Globulin: Progress Report

A total of 2,500 ml. of rabies immune globulin of human origin (HRIG) has been produced by the Rabies Unit of the National Communicable Disease Center, Public Health Service, and is now being tested in human beings. This globulin has passed all safety tests, and it contains 165 international units per ml., which is equal to the potency of antirabies serum of equine origin (ARS) now prescribed in the United States for persons exposed to rabid animals. Human rabies immune globulin gave animals challenged with rabies virus as much protection as ARS. The next step is to develop for human use a satisfactory regimen of HRIG in conjunction with rabies vaccine. Being a homologous globulin, this HRIG should preclude serum sickness in exposed persons who are sensitive to equine serum.