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Show Scientists develop new vaccine to immunize against snake bites A new vaccnie wheih provides pro-vides immunization against poisonous poi-sonous snakebites has been developed de-veloped by researchers at the University of Utah and the Veterans Administration Hospital Hos-pital in Salt Lake City. Dr. Clifford C. Snyder, principal prin-cipal investigator on the research re-search project and Gary R. Hunter, third-year medical student stu-dent who has conducted much of the laboratory work, say the vaccine has alreadly proven effective ef-fective in experimental animals and will be ready for equested trial among a few selected veterinarians vet-erinarians this fall. Dr. Snyder is chairman of the Division of Plastic Surgery at the University of Utah College Col-lege of Medicine and chief of surgery at the VA Hospital. Mr. Hunter is one of Dr. Snyder's Sny-der's research students who presented an award-winning paper on the treatment of envenoms en-venoms tion at the Student Scientific Sci-entific Seminar sponsored by the Student American Medical Association earlier this year. "Our experiments have shown that it is possible to immunize im-munize humans against snake venom," Dr. Snyder said. "Such a vaccine would be valuable to outdoorsmen, game conservation conserva-tion officers, serpentologists, armed forces personnel and others who are exposed to possible pos-sible poisonous snakebites." . One member of the research team who has already tried the vaccine on himself has shown no ill effects, and the level of antibodies in his blood remains high after more than a year. The researchers are also worrking on an antivenin the serum given to victims after af-ter they are bitten by poisonous poison-ous snakes that will be less likely to produce allergic reactions. re-actions. Antivenin now on the market is derived from the blood of horses that have been injected with snake venom, but many people are allergic to it. The serum developed by the U research team is taken from the blood of humans who have suffered natural snakebites. When the new vaccine is perfected per-fected for humans, the antivenin antiven-in can also be derived from the blood of persons that have been vaccinated, according to Dr. Snyder. The vaccine comes from pure venom that is extracted from several species off snakes kept at the VA Hospital's animal research re-search facility by the researchers. research-ers. The venom is purified and its severe toxic characteristics characteris-tics removed by a special process. pro-cess. When the toxoid is injected in-jected into animals it still produces pro-duces the desired antibodies without destroying tissue. Fifteen dogs received the vaccinations d u r ing clinical tests last summer, Mr. Hunter said. All fifteen dogs, when later la-ter challenged by double lethal doses of pure rattlesnake venom, ven-om, survived with only slight soreness and minor swelling at the injection sites. Though each dog received much more venom than p. snake would deliver in a natural bite, the animals showed show-ed only minor discomfort. Non-vaccinated Non-vaccinated dogs if given half the amount of venom would experience ex-perience immediate excruciating excruciat-ing pain, respitatory difficulty and death within 24 hours. Dr. Snyder says there is much to be learned before vaccine vac-cine can be made available for human use, but he foresees no insurmounta b 1 e obstacle in acheiving this goal. When the vaccine is finally perfected and tested by the Food and Drug Administration, Dr. Snyder plans to turn it over to the University which in turn can negotiate for commercial manufacture man-ufacture with a pharmaceutical company. "I would like to emphasize that vaccine is still very much in the exeprimental stages," Dr. Snyder said. "Even though we are pleased with the preliminary pre-liminary results, it may be some time before it is generally available to veterinarians or ready for trial in humans." Dr. Snyder foresees the day when mankind will no longer have to fear poisonous ssnakes. Thousands of people now die every year from snake enven-cmation, enven-cmation, most of them in Asia. About 7,000 persons are bitten every year in the U. S. by rattlesnakes, copperheads, cot-tonmouths cot-tonmouths and coral snakes. While the death rate in this country is less than 15 per year many people are disfigured for life because of the toxic effects of the venom. |