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Vaccine Against Fentanyl Proves Effective In Rats, Ready To Move To Humans

It could be a game-changer against the opioid epidemic in the USA.


Jack Dunhill


Jack Dunhill

Social Media Coordinator and Staff Writer

Jack is a Social Media Coordinator and Staff Writer for IFLScience, with a degree in Medical Genetics specializing in Immunology.

Social Media Coordinator and Staff Writer

bag of fentanyl held by a blue glove
Fentanyl has a lethal dose of just 2 milligrams. Image credit: Darwin Brandis/

Researchers have created a vaccine that prevents fentanyl entering the brain and creating a “high” in rats, claiming it could form part of a solution to the opioid epidemic that is currently gripping the USA if the results are replicated in humans.  

Fentanyl is a synthetic opioid that is often used by people to get an intense sensation that is significantly stronger than that from heroin, and it is often cut with heroin by drug dealers to increase potency and profits. However, being 50 times stronger than heroin, fentanyl is remarkably easy to overdose on, and just 2 milligrams is enough to be fatal, leading to a crippling crisis in which over 150 people die each day from synthetic opioid overdoses. 


By blocking the desired effects of fentanyl, researchers hope they can help prevent some of these deaths. 

“We believe these findings could have a significant impact on a very serious problem plaguing society for years – opioid misuse. Our vaccine is able to generate anti-fentanyl antibodies that bind to the consumed fentanyl and prevent it from entering the brain, allowing it to be eliminated out of the body via the kidneys. Thus, the individual will not feel the euphoric effects and can ‘get back on the wagon’ to sobriety,” said lead author Colin Haile in a statement

The vaccine induces the body to create antibodies against fentanyl and contains dmLT, which boosts the body’s immune response to vaccines. When administered to rats, the anti-fentanyl antibodies neutralized the levels of fentanyl in the rats and lowered the amount in the brain, but did not do the same for morphine. No adverse effects were noted from the vaccine in rats. 

It could be a game-changer in the fight against opioid misuse, as there are currently extremely limited treatment options for people addicted to heroin and other opioids. One study found a 91 percent relapse rate for sober heroin addicts, so a vaccine against one of the biggest threats to life could at least minimize these peoples’ chances of overdose by fentanyl. 


“Fentanyl use and overdose is a particular treatment challenge that is not adequately addressed with current medications because of its pharmacodynamics, and managing acute overdose with the short-acting naloxone is not appropriately effective as multiple doses of naloxone are often needed to reverse fentanyl’s fatal effects,” said Therese Kosten, senior author of the study. 

Now, the researchers hope to manufacture the vaccine at a clinical grade to make the transition to human trials, which are set to begin in the coming months. 

The study was published in the journal Pharmaceutics.


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