Production of a pan-specific antivenom against elapid snakes
Snake venoms are produced by snakes for digestion and to rapidly immobilize their prey. Venoms contain various hydrolytic enzymes and toxins e.g., neurotoxins and cytotoxins. Neurotoxic venoms are mainly produced by elapid snakes (cobra, krait, mamba) and sea snakes. These toxins cause neuromuscular blockage, leading to respiratory failure and death. Postsynaptic neurotoxins (PSNTs) from different elapids, although chemically and pharmacologically similar, are immunochemically distinct, so antivenom (AV) against venom from one elapid usually fails to neutralize venom of another elapid, even from the same genus. Thus, each country or region needs to produce its own AV, which is not economically or technically always possible. The lack of effective AVs has resulted in numerous deaths of snakebite victims. Our aim is to produce a pan–specific antivenom against venoms of Southeast Asian elapid snakes.
Previously we have established an immunization protocol (WHO Guidelines, 2010), which is highly effective in producing high titer and high affinity antibody against PSNTs of various snakes. Potent polyspecific antivenom has been produced against 3 elapids from Thailand with ED50s comparable to the corresponding monospecific antivenoms. Using this immunization protocol with selected neurotoxins from various elapids, we are studying the preparation of a pan-specific antivenom against elapids of SE Asian countries. If successful, this antivenom could be produced for wide distribution and, with economy of scale, should be quite cheap, widely available and save the lives of snakebite victims in many countries.