“We are literally vaccinating healthy people now,” says Susan Domchek, an oncologist at the University of Pennsylvania who is leading a trial of a preventive breast cancer vaccine. “It’s not just pie in the sky, we’re actually doing it.”

She is one of several researchers making serious headway toward that ambitious goal. Decades of work to understand how to train the immune system to spot tumors has culminated in a cluster of clinical studies of breast cancer vaccines that aim to be truly preventive. Read more …