New Vaccine Could Stop Heroin Abuse by Blocking High, Study Suggests

In Vermont, an individual dependent on heroin prepares drugs to shoot intravenously. A new study suggests that a vaccine could block the heroin high. Spencer Platt/Getty Images

A vaccine that blocks the high from heroin has just moved one step closer to reality.

The compound, created by chemists at the Scripps Research Institute, works in a way that's similar to other vaccines. By introducing the immune system to a potential future enemy, antibodies against that invader are ready to attack when the time comes. In this case, the vaccine introduces a piece of the heroin molecule to the immune system. In response, this protective system manufactures antibodies to the drug, including the components that cause the high.

As a result, those molecules never reach the brain, preventing the euphoria that may have otherwise resulted. The absence of a high could help recovering heroin users resist the temptation to relapse, the researchers say.

The current study of the vaccine, published in the Journal of the American Chemical Society, follows eight years of laboratory research and studies in rodents that indicated the compound could neutralize heroin at different doses.

Here, the Scripps investigators, working with researchers at Virginia Commonwealth University, tested the vaccine on four rhesus monkeys. The animals were given three doses of the vaccine, which elicited a successful immune response that neutralized heroin given at varying doses. The high-blocking effects of the vaccine were strongest during the first month but continued for more than eight months. The researchers did not observe any harmful side effects from the intervention.

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Two of the animals had been exposed to the vaccine seven months before for a similar pilot study. All four monkeys responded to the vaccine, but the two that were receiving it a second time had a stronger response, hinting that their immune systems were already primed with the "memory" of the compound.

Mark Thomas, who researches addiction at the University of Minnesota Health Sciences, says that a vaccine like this could help a former heroin abuser, "forge a path to abstinence." Thomas, who was not involved with the study, explains that he was initially wary of the vaccine approach. He figured that a person who is dependent on drugs would find a replacement if heroin no longer caused a high.

"It's not going to be a panacea," says Thomas. But in light of the growing drug abuse epidemic, for which, he says, "we have so few tools," adding a vaccine to the available treatments could help. "It's an avenue that shows some promise."

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Although research on humans is not yet planned, study authors Kim Janda and Paul Bremer, chemists at the Scripps Research Institute, are encouraged about this next step. Other anti-heroin vaccines have proved ineffective for people, but this compound is the first to work in primates. "We believe this vaccine candidate will prove safe for human trials," said Janda in a statement.

Importantly, this vaccine is designed to work against only heroin, not other opioids. Bremer and Janda now hope to find a company interested in conducting a human study so that the vaccine can become commercially available.

Related: CDC study finds opioid dependency begins within a few days of initial use