Rodent Study of Vaccine Shows Promise Against Fentanyl

A vaccine combining a fentanyl antigen and a tetanus toxoid decreased dangerous drug-taking behavior and encouraged healthier choices in a study using rats, according to new research published in the journal Neuropsychopharmacology.

Study co-author Kim Janda of Scripps Research developed the vaccine cocktail, which is designed to generate an immune response against fentanyl and related compounds. Janda and colleagues wrote, “More effective and readily available treatments for opioid use disorder are needed to tackle the current crisis. One strategy includes using opioid-targeted vaccines to elicit antibody production by the host's immune system that recognize and block the passage of a specific opioid into the brain and peripheral organs/tissue.”

The rat study involved a behavioral procedure in which the rodents chose between receiving fentanyl injections or food. A tendency to choose fentanyl was found to shift within four weeks of receiving the vaccine, as the rats increased their food choices. Two vaccinations at weeks one and three of the study resulted in decreased fentanyl choice for 15 weeks, a finding that suggests a long-lasting effect.

The researchers reported that the effect seen in this study was similar to that from studies in which rats were chronically treated with the opioid antagonist naltrexone.