Anti-cocaine vaccine eats up drug ‘like a little Pac-Man’



An anti-cocaine vaccine has been used successfully on non-human primates, bringing it one step closer to approval for use in human addiction therapy.

The vaccine (dAd5GNE) combines elements of the common cold virus with the particle GNE, which mimics cocaine. The vaccine works by preventing the dopamine high associated with taking cocaine.

“The vaccine eats up the cocaine in the blood like a little Pac-Man before it can reach the brain,” said Ronald G Crystal, lead author of the study and chairman of the Department of Genetic Medicine at Weill Cornell Medical College.

“We believe this strategy is a win-win for those individuals, among the estimated 1.4 million cocaine users in the United States, who are committed to breaking their addiction to the drug. Even if a person who receives the anti-cocaine vaccine falls off the wagon, cocaine will have no effect.”

Cocaine works by binding to a dopamine transporter and blocking the recycling of dopamine in two areas of the brain (the putamen in the forebrain and the caudate nucleus, in case you were wondering) meaning those areas get flooded with dopamine and produce the drug high. The vaccine encourages the body to treat cocaine as an intruder and mount an immune response against the drug.

According to the results of the study, non-human primates who had received the vaccine showed greatly reduced levels of cocaine binding to the dopamine transmitter. Less than 20 percent, in fact, which the study notes is “significantly below the 47 percent threshold required to evoke the subjective ‘high’ reported in humans”.

The results look promising but, if the vaccine is to help humans rather than coked up primates of different species, further studies will be required. One of the key questions non-human testing cannot help with is how effective the vaccine will actually be and how often it would need administering.

“An anti-cocaine vaccination will require booster shots in humans, but we don’t know yet how often these booster shots will be needed,” said Crystal. “I believe that for those people who desperately want to break their addiction, a series of vaccinations will help.”

To find out more about the research, don’t miss this in-depth feature from our March issue, titled Addiction injection: the mission to immunise drug users against dependency.