Protective effect of snake venom antibodies in sera of previous snake bite victims.

Three out of seven serum samples from Ecuadorian Indians had very high antibody levels against Bothrops nasutus venom, and IgG concentrates of these sera effectively neutralized this venom when subsequently injected into mice. It is concluded that the high mortality rate among these Indians would be even higher if there were not such natural protection. Further research into active immunization of humans should be encouraged.