American-Eurasian Journal of Toxicological Sciences 2 (2): 62-71, 2010 ISSN 2079-2050 © IDOSI Publications, 2010 Corresponding Author: Khaled F. Mohamed, Department of Microbiology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt. 62 Production of Polyvalent Region-Specific Antivenom A.F. Philadelphia Wahby, Nashwa A. Ezz El-deen, Kh. F. Mohamed, 1 2 2 Ahmed Samir, M. El-Hariri, A. Fekry and R. Soliman 2 2 3 2 The Holding Company for Biological Products and Vaccines (VACSERA), Egypt 1 Department of Microbiology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt 2 National Research Center, Giza, Egypt 3 Abstract: This study was carried out on horses belonging to the Holding Company for Biological Products and Vaccines (VACSERA). Two immunization protocols used for preparation of polyspecific horse antivenins were evaluated. The first and second immunization schedules followed by a rest period of about one month ended by re-immunization schedule. The antivenoms were raised to venoms of the four major snakes of South Sinai (three vipers”Cerastes cerastes, Echis coloratus, Pseudocerastes fieldi” and the elapid ‘Walterinnesia aegyptia”). Therapeutical titers were obtained by applying the two immunization schedules however, a faster response was obtained by using a mixture of venoms rather than individual venoms. Furthermore, although the preparation of polyspecific antisera to a group of venoms is less costly, the data showed that it is practical to prepare polyspecific antivenom to a group of vipers not for both vipers and elapids. Eventually, the most logical procedure for preparation of polyspecific antisera to a group of vipers and elapids is by mixing antisera raised for vipers with another raised for elapids. So this work achieved the aims of producing potent polyvalent antivenom suitable for use in a specific area and replacing the already present technique (in vitro mixing of monospecific antivenom prepared separately in horses) by immunization of horses with the different venoms as well as preparation of polyspecific antivenom from single horse. Key words: Snakes Antivenom Polyvalent Region-Specific INTRODUCTION Around the world, there are many different Snakebites represent a serious public health problem against single venoms and are only effective against in many areas of the world. Traditional treatment is sought those specific venoms (monovalent or monospecific by most victims. Many survivors of snakebites are left antivenoms). There are also antivenoms made by permanently maimed. The African savanna region, South immunizing the same animal using several venoms from Africa, the Indian subcontinent, South East Asia, China, different snake species or combining the serum antibodies New Guinea and Central / South America are the worst from several animals immunized against the venom of affected. Community-based studies have shown that particular snake species. These so-called “Poly-valent or between 4 and 162 annual snakebites fatalities per 100,000 polyspecific antivenoms” have a broader spectrum of population. Unlike most classical tropical diseases, activity [1]. snakebites are increasing, due to man made environmental The term "monospecific antivenom" refers to an changes, which encourage colonization of populated antivenom raised against the venom of a single species or areas by new and more dangerous species. The clinical sub-species of a venomous animal. The term "polyspecific history of snakebite is usually unambiguous, but the antivenom" refers to an antivenom raised against a snake responsible is rarely brought. In humans, mixture of two or more venoms from different species or pathophysiological mechanisms of envenoming include sub-species of a venomous animal [2]. tissue damage and inflammation, cardiovascular The critical problems associated with supply and disturbances and haemorrhagic diathese. Some venom distribution of antivenoms in Sub-Saharan Africa were toxins rapidly cause irreversible effects. reviewed by Theakston et al. [3]. In Africa, snakebites antivenoms available, most of which are produced