Scientists Develop Vaccine to Block Opioid Drugs’ Effects

With the rising epidemic of opioid drug overdoses, a new vaccine that blocks the pain-numbing effects of the drugs oxycodone(oxy) and hydrocodone(hydro) has shown success in animal models. When opioid drugs reach receptors in the brain, they reduce pain and elicit feelings of euphoria. But, the new oxy/hydro vaccine uses the immune system to recognize, seek out and neutralize the drug’s molecule.

To develop the vaccine, scientists at The Scripps Research Institute (TSRI) combined a signature opioid structure with a molecule to trigger an immune response. When injected, the vaccine teaches the immune system to bind to the drug molecule and remove it from circulation, thus depriving a person of the effects of the drug. According to the scientists, it’s possible that the vaccine could have an advantage over current opioid addiction therapies because it would not alter brain chemistry like many of today’s anti-addiction therapies. In studies, the researchers found that the oxy/hydro vaccine blocked pain perception in most mice, which meant they did not display the usual symptoms of a drug high such as ignoring pain and discomfort. In addition, they appeared less susceptible to fatal overdose, and the vaccine remained effective for the entire 60-day study period. In those that did succumb to the opioid’s toxic effects, it took much longer for the drug to impart its toxicity.

While this is not the first vaccine tested to block the effects of opioids, it is the first to use a faithful representation of the opioid in its design. The next steps will be to investigate the vaccine’s optimal dose and schedule.