Fentanyl Vaccine Put Rats off Opioid in Study

A vaccine against fentanyl—a drug contributing to the opioid crisis gripping the U.S.—appears to have put rats off the substance in a study. 

Between 2010 and 2016, there was a 493 percent spike in people being diagnosed with opioid addiction, in what the National Institute of Drug Abuse describes as a national crisis. In that time, deaths caused by fentanyl hit 19,413 a year, amounting to a 646 percent increase since 2010. The synthetic opioid is up to 50 times stronger than heroin, and has been sold by drug dealers because of its high profit margin compared with other opioids.

The crisis has seen lawmakers and scientists double-down on efforts to tackle addiction and gain a deeper understanding of the condition.

Dr. Matthew L. Banks, associate professor of pharmacology and toxicology at VCU School of Medicine, and professor Kim D. Janda of The Scripps Research Institute co-authored a study published in the journal Neuropsychopharmacology.

They commented: “One strategy includes using opioid-targeted vaccines to elicit antibody production by the host’s immune system that recognizes and block the passage of a specific opioid into the brain and peripheral organs/tissue.”

Their research looked at immunopharmacotherapies: or drugs that work against substances like fentanyl to stop addiction. Such treatments don’t appear to cause bad side effects and they are specific to particular substances, meaning patients can be treated with other painkillers in a medical setting if needs be, the authors explained.

The scientists created a vaccine designed to stop rats from craving fentanyl by triggering an immune response against the drug. To test it, they dosed mice addicted to fentanyl twice over a three-week period, with either the experimental vaccine or two medications currently used to treat substance addiction (naltrexone and clonidine). The team documented whether the rats would seek out fentanyl or food after taking the medicine.

Rats who took the vaccine were more likely to choose food over fentanyl for 15 weeks after being administered with the vaccine, the scientists showed in their paper.

But as the drug was tested in rats, it is unclear whether it is safe for, or will work in, humans. Also, as the authors stated in their study, individuals need strong immune systems for the drug to work. It can also take weeks for the vaccine to reach its full potential. 

Earlier this year, a separate study published in the journal JAMA Network Open looking at the causes of the opioid crisis linked painkiller marketing aimed at physicians to higher numbers of overdoses.