There’s probably no place in the world with more 12-step meetings than Southern California. In fact, drug dependency is a huge problem everywhere in the U.S. The National Institute on Drug Abuse estimates addiction costs the economy more than $600 billion a year. For decades, scientists have been working to find a “cure” for addiction. Now, for the first time, their efforts are showing promise: not for a cure, but for a vaccine against addiction. We hear all about how it would work.