Brazilian researchers have engineered a protein that should make producing antivenoms to treat spider bites both cheaper and simpler. The protein may also pave the way for a vaccine, as it can prime the immune system to cancel out the worst effects of the spider venom.Venomous spiders inflict pain, injury and even death in several parts of the world. Those bitten often need to be treated with an antivenom, a serum containing specific animal antibodies against the venom toxins. Antivenoms are currently produced by injecting the venom into an animal to provoke an immune response. But a single spider only...