Equine Rabies Immunoglobulin: A Review

Abstract

Rabies is a major cause of human death in many developing countries. There is a worldwide shortage of human and equine rabies immune globulin. The WHO recommends combined administration of rabies vaccine and rabies immune globulin to patients after exposure. The implementation of post exposure prophylaxis by vaccination and specific immunoglobulin therapy are largely hampered by its high cost. The equine rabies immunoglobulin is less expensive than human rabies immunoglobulin, and is used for rabies post-exposure prophylaxis in developing countries.

Equine rabies immunoglobulin is a F(ab)2 with high specific activity, purity, and safety. Healthy horses are immunized with a rabies vaccine. Crude plasma is collected and immunoglobulin is converted into F(ab)2 fragments by pepsin digestion. The F(ab)2 fragments are purified using caprylic acid precipitation followed by ultrafiltration.

Keywords: Rabies, Equine rabies immunoglobulin (ERIG), Human rabies immunoglobulin (HRIG), IgG, Caprylic acid, Pepsin.