One of the white whales of vaccine research - a cure for addiction - is a very small step closer to reality. Last week, researchers working at the Walter Reed Army Center published a study showing that their experimental vaccine was able to block the euphoria-inducing effects of heroin and other commonly abused opioids in mice and rats. Almost as importantly, the vaccine didn't dampen the effects of other related drugs like methadone, which are used (controversially) to wean people off opioid addiction.