This may be some of the more encouraging news in the faltering “war on drugs”:

Vaccines for addictive drugs work just like those for the flu: they trigger the immune system to produce antibodies that bind to the foreign substance and inactivate it. Molecules of cocaine, methamphetamine, nicotine, and other drugs are too small to spark an antibody response on their own, so scientists attach drug-like molecules to larger proteins that trigger formation of antibodies when injected into the blood. When a person takes a drug that he or she has been vaccinated against, antibodies bind to it and reduce the amount of drug that reaches the brain.

An addict who has been vaccinated might still fall off the wagon, but he or she wouldn’t get the rush of that next snort of cocaine or meth. Addiction experts say that thwarting the high should help prevent the person from spiraling back into regular use, allowing him or her to return to therapy or a treatment program much more quickly. “It could be comforting to know that even when you have dark moments and slip, you have the opportunity to get back on track,” says Michael Owens, a psychopharmacologist at the University of Arkansas for Medical Sciences, in Little Rock.

Long-awaited nicotine vaccines are likely to be the first available on doctors’ shelves. In initial clinical trials of smokers who were administered an experimental vaccine, a third of those given the highest dose quit, even though they were not asked to, versus 9 percent of those given placebos. A larger study of 200 patients has just concluded, with results expected in April.

Great. So pretty soon Kate Moss can legitimately wear a t-shirt proclaiming “I’ve shot up. Have you?”