Ricin is a highly lethal toxin derived from castor beans. U.S. researchers have developed a genetically engineered vaccine against it. According to the results of a small study, it appears safe and stimulates an immune response at high doses
“Ricin represents a potential agent for use in biological warfare and is classified by the Centers for Diseases Control and Prevention as a level B biothreat,” the investigators report in the Proceedings of the National Academy of Science.
Dr. Ellen S. Vitetta, lead author of the University of Texas Southwestern Medical Center in Dallas claimed that her group’s vaccine, called RiVax, is one of several currently in development by researchers in the U.S. and elsewhere. Combined with the bacteria E. coli, the vaccine is based on a mutated version of the ribotoxic A chain of ricin.