Opioid Vaccine Shows Promise in Early Testing

Researchers have reported that a newly developed vaccine that could combat both opioid dependency and overdose has yielded what appear to be positive results in animal testing. The vaccine, which uses monoclonal antibodies – antibodies made by identical copies of immune cells – appeared to block both the analgesic properties of synthetic opioids like fentanyl, as well as their high propensity of producing a fatal overdose, when administered in preliminary tests.

The researchers have begun developing antibodies in the hope of testing their vaccine on humans.

Researchers from The Scripps Research Institute, which conducted the tests, presented their findings on December 13 at the annual meeting of the American College of Neuropsychopharmacology. The study detailed the creation of the monoclonal antibodies as well as two tests of their efficacy involving mice.

In the first test, the research team measured pain response using a heated beam of light that was applied to a mouse’s tail. An immediate response – specifically, the mice removed their tail from the light – suggested that the animal experienced a degree of pain, while a delayed response suggested that the pain had been dulled.

Mice were then given a synthetic opioid such as fentanyl and exposed to the light beam, which produced a longer response time due to the pain-dulling properties of the drug. However, when given the antibodies, the researchers found that the mice withdrew their tails at a faster rate, which suggested that the vaccine had blocked the drug’s analgesic effect.

In the second test, mice were given the vaccine, followed by a dose of fentanyl that had proven fatal in other test animals. According to the study, the mice did not experience overdose. In both tests, the antibodies proved effective against seven other synthetic opioids, including carfentanil, which the Centers for Disease Control (CDC) described as the “most potent fentanyl analog detected in the United States” and which has been linked to a number of overdose deaths.

As US News and World Report noted, research of this nature involving animals does not always produce the same results in human test subjects, so the study authors are in the process of developing human antibodies and hope to test them in the future.

“Antibodies persist longer, and thus have enormous promise for addressing both opioid addiction as well as overdose,” said study leader Kim Janda in a press release.

In addition to the vaccine’s possible use with drug users, Janda and his fellow authors believe that it may have a practical application as a safeguard for individuals who may come in contact with synthetic opioids. “These antibodies could be used to protect police, EMTs and other first responders from inadvertent acute fentanyl exposure,” he said, adding that a canine version could also be applicable for drug-sniffing dogs.