Researchers Developing Vaccine to Fight Opioid Use Disorder

Scientists with a new research center at the University of Washington are working on a vaccine to help fight the opioid epidemic in a bid to stem the tide of overdose deaths that has swept the nation over the past two decades. 

Marco Pravetoni, the head of the new UW Medicine Center for Medication Development for Substance Use Disorders, is leading the effort to develop the vaccine. Similar to immunization against an invading pathogen, the vaccine under development would stimulate the body’s immune system to attack and destroy opioid molecules before they can enter the brain. 

Such a vaccine would not prevent drug cravings commonly experienced by those with opioid abuse disorder. But the treatment, if successful, would block the effects of opioids including euphoria, pain relief and even overdose, thus likely reducing abuse.

The new research center opened this month and has raised more than $2 million in initial funding. Pravetoni hopes to raise enough money to complete further research on the vaccine under development.

“What I’m hoping to achieve is pretty much every year, we’re going to start a new clinical trial,” Pravetoni told the Seattle Times in early January.

An Epidemic of Opioid Overdoses

In November, provisional data from the U.S. Centers for Disease Control and Prevention showed that during the 12-month period ending April 2021, 100,306 Americans died of drug overdoses. Synthetic opioids were involved in nearly two-thirds of the overdose deaths reported.

The overdose-reversal drug naloxone has been shown to save lives in emergencies. Additionally, treatments for opioid abuse disorder including methadone and buprenorphine can help those struggling with addiction, although opioid replacement therapy drugs have their own risk of addiction. New treatments could increase the chances of success for those struggling with opioid abuse, according to Rebecca Baker, director of the National Institutes of Health’s Helping to End Addiction Long-term Initiative, a program that has helped fund Pravetoni’s research.

“(Existing medications) don’t work for everyone. And a lot of people don’t stay on them in the long term,” Baker said. “Would the outcomes be better if we had more options?”

The University of Washington’s opioid vaccine project is building on research published in the journal Nature in 1974. In that study, a rhesus monkey had been trained to self-administer heroin and cocaine. After being given an experimental vaccine to block the effects of heroin, the monkey continued to use cocaine but greatly reduced its use of heroin, suggesting the vaccine had done its job.

That study led to further research into the possibility of creating a vaccine for nicotine addiction. Although early results appeared promising, human trials showed the treatment was only as effective as a placebo. A vaccine developed to fight cocaine addiction saw a similar fate, and neither treatment received approval from the Food and Drug Administration.

Kim Janda, a chemistry and immunology professor at Scripps Research Institute in California, has spent decades researching vaccines against addictive drugs. He believes that continued research could eventually produce an effective vaccine.

“We’ve learned a lot more [about] what is possible, what’s maybe not going to be as fruitful,” Janda said, adding that vaccines may not work against all drugs of abuse. “But if there’s enough money to put behind these vaccines, and you had the infrastructure to do it, then you could move it along fairly quickly.”

This year, Pravetoni and a researcher with Columbia University have launched the first Phase 1 clinical trial of a vaccine to prevent opioid abuse. The safety and efficacy of the vaccine, which is designed to block the effects of oxycodone, is being tested in people who are already addicted but not receiving the disease.

Is an Opioid Vaccine Worth the Cost?

But human drug trials are expensive. Pravetoni estimates that bringing an effective opioid vaccine to market could cost up to $300 million. Some addiction experts, including Dr. Ryan Marino, an emergency medicine physician and medical toxicologist at Case Western Reserve University in Ohio, wonder if the money could be better spent.

“It is true that more treatment options are generally better,” Marino told Filter. “But what doesn’t make sense to me—as someone who treats both overdose and addiction—is putting so much funding towards this when we already have an antidote for opioids, a long-acting opioid blocker and two other evidence-based treatment options for opioid use disorder that both reduce opioid use and prevent overdose.”

Harm reduction activists working on the ground with people who have substance abuse disorders say that limited funds could be spent more effectively. Jessica Blanchard, the founder of Georgia a mobile harm reduction program called 229 Safer Living Access, distributes safer sex supplies and naloxone provided by other groups. But she personally covers the other costs to administer the program, which limits its operations substantially.

“With funding, not only could I afford to buy in bulk, greatly reducing cost, but I could also give participants more supplies to share with those unable to make contact with the program,” Blanchard said. “I would pay program participants to do secondary distribution. (They) are the experts here. They express a desire to participate in distributing supplies and educating their peers. But without the ability to compensate them for their time and lived-experiential knowledge, I simply can not ask them to help.”