Scientists in Brazil have developed a vaccine, called Calixcoca, which shows promise in treating addiction to cocaine and crack. The vaccine triggers an immune response that blocks the drugs from reaching the brain, preventing users from experiencing the high associated with the drugs. The vaccine has been successful in trials on animals, producing significant levels of antibodies against cocaine with few side effects. If the treatment receives regulatory approval, it would be the first time a vaccine is used to treat cocaine addiction. The vaccine is set to enter the final stage of trials on humans.