Abstract
Snake envenomation has been estimated to affect 1.8 million people annually with about 94,000 deaths mostly in poor tropical countries. Specific antivenoms are the only rational and effective therapy for these cases. Efforts are being made to produce effective, affordable and sufficient antivenoms for these victims. The immunization process, which has rarely been described in detail, is one step that needs to be rigorously studied and improved especially with regard to the production of polyspecific antisera. The polyspecific nature of therapeutic antivenom could obviate the need to identify the culprit snake species. The aim of this study was to produce potent polyspecific antisera against 3 medically important vipers of Thailand and its neighboring countries, namely Cryptelytrops albolabris "White lipped pit viper" (CA), Calleoselasma rhodostoma “Malayan pit viper” (CR), and Daboia siamensis “Russell’s viper” (DS). Four horses were immunized with a mixture of the 3 viper venoms using the ‘low dose, low volume multi-site’ immunization protocol. The antisera showed rapid rise in ELISA titers against the 3 venoms and reached plateau at about the 8th week post-immunization. The in vivo neutralization potency (P) of the antisera against CA, CR and DS venoms was 10.40, 2.42 and 0.76 mg/ml, respectively and was much higher than the minimal potency limits set by Queen Soavabha Memorial Institute (QSMI). The corresponding potency values for the QSMI monospecific antisera against CA, CR and DS venoms were 7.28, 3.12 and 1.50 mg/ml, respectively. The polyspecific antisera also effectively neutralized the procoagulant, hemorrhagic, necrotic and nephrotoxic activities of the viper venoms. This effective immunization protocol should be useful in the production of potent polyspecific antisera against snake venoms, and equine antisera against tetanus, diphtheria or rabies.
Highlights
Snake envenomation is an important yet neglected health problem in many poor tropical countries [1,2] with an estimated 1.8 million people are affected worldwide resulting in approximately 94,000 fatalities annually [3]
Most antivenoms are specific for the treatment of one single snake species and necessitate catching the culprit snake so the correct antivenom can be administered
Studies currently are being conducted with the aim of eliminating these shortcomings and to produce polyspecific antivenom capable of neutralizing multiple snake venoms
Summary
Snake envenomation is an important yet neglected health problem in many poor tropical countries [1,2] with an estimated 1.8 million people are affected worldwide resulting in approximately 94,000 fatalities annually [3]. Pratanaphon et al [11] showed that if the CFA emulsified immunogen preparation was injected in small volumes (i.e., 0.1–0.2 ml) at many sites covering a wide anatomical area of the neck, severe adverse local reactions caused by the adjuvant could be avoided. This simple immunization protocol has resulted in a dramatic increase in the numbers of responder horses and in the potency of the antisera [8,11]. A low venom dose, complete Freund’s adjuvant and incomplete Freund’s adjuvant (CFA/IFA)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
