Protection against the lethal effects of Crotalus durissus terrificus (South American rattlesnake) venom in animals immunized with crotoxin.

Mice and rabbits were immunized against crotoxin (the neurotoxic component isolated from Crotalus durissus terrificus venom) using small amounts of antigen in a water-in-oil emulsion. Following boosting (three times at 21-day intervals) a high titre of antibodies against crotoxin was obtained. Crotoxin immunoglobulin G antibody recognizes whole venom antigen at a level comparable with that of crotoxin antigen, using the ELISA method for antibody detection. The antibodies generated by crotoxin were capable of providing 100% protection against challenge with 11 and 50 i.p. LD50 doses of whole venom in mice. When 100 i.p. LD50 doses of whole venom were injected survival was 77.8%.