A new vaccine shows promise in heroin addiction treatment, a study in rats suggests. Medical News Today reports scientists at The Scripps Research Institute in La Jolla, CA, have developed a vaccine which produces antibodies that prevent heroin from reaching the brain to produce feelings of euphoria.

“The hope is that such a protective vaccine will be an effective therapeutic option for those trying to break their addiction to heroin,” study lead author Kim D. Janda said in a news release.

The vaccine targets not only heroin, but also the chemical it degrades into, which also produces an effect on the brain. The researchers found that rats addicted to heroin were less likely to give themselves heroin by pressing on a lever if they had received several booster shots of the vaccine, compared with addicted rats who did not receive the new vaccine.

The study appears in the Journal of Medicinal Chemistry.

The Scripps Research Institute has begun working with researchers at the Walter Reed Army Institute of Research on development of a vaccine against both HIV and heroin addiction, the article notes.