Relapse is the number that drives this research. Jay Evans, who leads a center at the University of Montana, said someone addicted to fentanyl who goes through rehab has an 80 to 90 percent chance of relapsing within two years. Some overdose, and some die, because their bodies are no longer used to the drug.
Evans and his partners are building a vaccine for people who want out. “We’re developing a vaccine to help people quit and prevent overdoses,” he said in 2023. A second vaccine for heroin is in the works alongside it. The university said human trials were expected to start in early 2024.
How it works
Most vaccines train the body against a virus or bacterium. This one trains it against a drug. Evans said a hapten, a molecule too small to set off an immune response alone, is linked to a carrier protein that the body reads as foreign. The immune system builds antibodies to the drug, and an ingredient called an adjuvant, supplied by the Montana team, strengthens that response. “Our adjuvants improve the vaccine response, providing a stronger and more durable immunity,” Evans said.
If a vaccinated person uses fentanyl again, the antibodies grab the drug in the bloodstream. It cannot cross the blood-brain barrier, so there is no high. The vaccine should also guard against overdose in a relapse.
Evans said the aim is protection lasting one to two years, no more. That way a patient could still get fentanyl for pain relief in a real medical emergency later on.
The partners and the timeline
The project grew out of a $33.4 million NIH contract with the university. NIH also brought Evans together with Marco Pravetoni, now at the University of Washington, at a workshop meant to link groups with complementary research. Pravetoni’s team supplied the ingredient that prompts antibodies against the target opioid. The universities of Montana, Washington and Minnesota each worked on parts of the project, and Columbia University in New York will run the clinical trials.
The first phase tests safety. Volunteers will be given fentanyl or heroin to show they suffer no ill effects. “So we’re going to get an early signal on whether the vaccine works,” Evans said. If everything goes smoothly, he said, the vaccine might reach the market in 2028, though many variables are in play.
The need
The university cited NIH data showing more than 106,000 overdoses in the United States in 2021, about 71,000 of them tied to synthetic opioids such as fentanyl. In Montana, 113 people died of opioid overdose that year, 62 from fentanyl.
Evans does not see the vaccine as a first-line treatment. People still hesitate to talk to doctors or family about drug use, he said. “It’s a disease. It’s not a choice.”
Anyone struggling with opioid use should consult a doctor.
