Chapter Twenty Four - Production of Equine Rabies Immune Globulin of High Purity, Potency, and Safety

Abstract

There is a worldwide shortage of human and equine rabies immune globulin (RIG). The equine (ERIG) is less expensive than human (HRIG), and is used for rabies post-exposure prophylaxis (PEP) in developing countries. Rabies is a fatal viral disease and still a major cause of human death in developing countries. The WHO recommends combined administration of rabies vaccine and RIG to patients after exposure.1 One example is produced by the Queen Saovabha Memorial Institute (QSMI), and the Thai Red Cross Society (TRCS) manufactures ERIG (“TRCS ERIG”), which is a F(ab′)2 with high specific activity, purity, and safety. Healthy horses, sero-negative for equine infectious anemia and equine influenza, are immunized with a tissue culture rabies vaccine. Crude plasma is collected by plasmapheresis and immune globulin is converted into F(ab′)2 fragments by pepsin digestion. The F(ab′)2 fragments are purified using caprylic acid precipitation followed by ultrafiltration. At least three consecutive batches of ERIG are validated and tested according to product specification, conforming to the requirements of the WHO and national Pharmacopoeias before each lot release.