Immunological studies on Egyptian polyvalent antivenins

Polyvalent antivenin was prepared against the Egyptian snake venoms Naja haje, N. nigricollis, Cerastes cerastes and C. vipera, and tested by neutralization and immunodiffusion tests. The antivenin was of high potency against the Egyptian snake venoms, especially C. cerastes and C. vipera, followed by Echis carinatus, E. coloratus, N. haje, N. nigricollis and Walterinnesia aegyptia. The titre against the African and Indian cobra venoms N. nivea, N. haje (Ethiopian) and N. naja was lower, while poor or no effect was shown against Bitis arietans, B. gabonica and Trimeresurus flavoviridis venoms. The polyvalent serum prepared in horses not previously immunized, was comparable to sera obtained by using horses, which were previously immunized against a single venom. However, the latter sera, still maintained their higher titre against the original sensitizing venom. Comparison of polyvalent and monovalent N. nigricollis antivenins, revealed that while the polyvalent serum was of better effectiveness against the Egyptian viper venoms especially cerastes venoms, more protection was provided by the monovalent serum against the naja venoms.