Three promising formulations could be used in a vaccine to treat methamphetamine addiction, U.S. researchers say. Kim Janda of the Scripps Research Institute in La Jolla, Calif., and colleagues note methamphetamine use and addiction cost the United States more than $23 billion annually due to medical and law enforcement expenses, as well as lost productivity. The highly addictive crystal meth can cause a variety of problems including cardiovascular damage and death. The study, published in the Journal of the American Chemical Society, found three of the new formulations that produced a good immune response in mice were particularly promising. These findings represent a unique approach to the design of new vaccines against methamphetamine abuse, Janda says. Previously tested meth vaccines either are not effective or are very expensive.