Poison ivy plant. (Photo by John Greim/LightRocket via Getty Images) Researchers are reportedly working on a vaccine to combat humans' response to poison ivy.According to Scientific American, scientists at the University of Mississippi and Hapten Sciences are "proceeding with a compound called PDC-APB" to be injected once every year or two to prevent the poison plant's effects. HORSE TRANQUILIZER CROPS UP IN OVERDOSE DEATHS AROUND THE US"We believe the shot will lead to desensitization and reduce or eliminate reactions to poison ivy, oak and sumac," Ray Hage, CEO of Hapten Sciences, told the outlet.