The Relative Efficiency of Two Types of Anti-Venom Sera in Neutralizing Cobra Venom

Abstract

DURING the summer of 1945 I was stationed Manila, P.I., with one of the United States Army Medical General Laboratories.1 During the course of the summer two snake antivenins were received at the laboratory for testing against the venom of the Luzon cobra, Naja naja philippinensis. According to Taylor ..... These snakes are poisonous, and probably cause more deaths than any other snake the Philippines. The subspecies is found very commonly Luzon, ... . Up to the time of the study two deaths from cobra bite had already been reported among U.S. military personnel stationed or near Manila and an efficient antivenin was being sought for use by the military forces. The two antivenins to be tested differed mainly the fact that one was a locally prepared (Institute of Hygiene, University of the Philippines) antivenin, specific for the venom of the Philippine cobra. This antivenin was prepared June, 1941, and packaged a 10.0 cubic centimeter hermetically sealed vial. It had an expiration date of June, 1942. The was prepared from horses hyperimmunized against the venom of N. n. philippinensis. The fact that this serum's expiration date was 1942 left its efficacy open to question, since liquid is considered unstable if stored at temperatures above 4? C. (39? F.). The other antivenin received was an Indian polyvalent Anti-snake venom serum prepared from horses hyperimmunized against four snakes: Russell's viper, Vipera russellii; the saw-scaled viper, Echis carinatus; the common krait, Bungarus caeruleus; an Indian cobra, Naja naja (subsp.?). This was desiccated, lyophilized, and packaged with sufficient sterile, distilled water, included a separate vial, to yield 10.0 cc. of reconstituted serum. Date of manufacture was July, 1945. The was prepared by the Haffkine Institute, Bombay, India. Both types of antivenin had been successfully used, but it was desired to check their relative efficiency against cobra venom, under controlled conditions. Since there was only a small quantity of each type of available for testing purposes, it was decided to use white mice for laboratory animals and to run the experiment in reverse, so to speak, order to obtain the most information from a given lot of antivenin. This will be explained more detail later.