Experimental vaccine could help turn the tide on America’s opioid epidemic
Researchers discovered a way to use nanoparticles to prevent the drug’s addictive high.
Mike Zhang conducting work on an experimental opioid vaccine that he hopes will be a useful tool in the fight against the ongoing opioid crisis. Photo by Briana Bittner for Virginia Tech.
Virginia Tech researchers are advancing a new generation of vaccines designed to block opioids from reaching the brain and triggering their addictive effects, work that could help prevent overdose deaths that now exceed 100,000 each year in the United States.
In a new study published in the Journal of Controlled Release, the researchers report that a novel hybrid lipid-polymer nanoparticle vaccine produced stronger immune responses and improved protection against oxycodone in mice. They also found that pairing a similar fentanyl-targeting vaccine with an immune-boosting adjuvant restored its effectiveness, offering a blueprint for vaccines aimed at curbing opioid use disorder and preventing overdose.
Led by Chenming "Mike" Zhang, professor and the Turner Faculty Fellow in the Department of Biological Systems Engineering, and supported by the National Institutes of Health, the team is developing targeted vaccines against opioids such as oxycodone and fentanyl.
Blocking opioid effects
Zhang and his team, assisted by College of Engineering undergraduate researcher Kari Cochran, created a delivery mechanism that uses biodegradable nanoparticles that mimic viruses in size and structure. These particles are coated with opioid molecules — such as oxycodone or fentanyl — so the immune system recognizes them as a threat. This virus-like structure enhances the vaccine’s ability to trigger a strong and lasting immune response.
“It’s similar to how we design vaccines for COVID-19 or influenza,” he said. “We want the body to recognize the drug as a threat and mount a defense.”
By stimulating the body’s immune system to produce opioid-attacking antibodies, it prevents opioids in the user’s system from crossing the blood-brain barrier, thereby blocking the euphoric effects typically associated with their use.
Early results suggest antibody levels remain effective for several months, and Zhang hopes optimization could extend protection to a full year.
The vaccine is also designed to be highly specific, targeting only the intended opioid molecule without interfering with other pain medications. This precision ensures that patients can still receive any necessary clinical treatments without compromising the vaccine’s protective effects.
Undergraduate researcher Kari Cochran pipettes vaccine samples in the lab. Photo courtesy of Mike Zhang.
Curbing future addictions
While the vaccine is not intended for general use like a flu shot is, it could be administered to individuals with opioid use disorder or those at high risk of exposure.
“Some of the oxycodone and fentanyl are so potent – you use it once or twice and you get hooked,” Zhang said. “If you can prevent people from getting hooked so quickly, that’s a big deal.”
Because of this, Zhang hopes his vaccine could serve as a deterrent for first-time users and at-risk youths.
“Some youth may be vulnerable to trying opioids,” Zhang said. “If they’re vaccinated, they won’t experience the high, which could deter future use.”
While the vaccine does not stop a user from using drugs, the hope is that it will curb the need to use, reducing accidental overdose and providing a safe way for individuals who have opioid use disorder to become less reliant on drugs.
Beyond individual patients, the vaccine could benefit families, communities, and health care systems.
“Reducing overdose deaths would alleviate emotional trauma, lower medical costs, and improve workforce productivity,” said Zhang.
While the vaccine is not a standalone solution, it is a promising start to curbing the opioid epidemic and accidental overdoses. Zhang hopes his research will inspire broader recognition of vaccines as tools not just for infectious diseases, but also for chronic conditions like addiction.
Original study: DOI 10.1016/j.jconrel.2025.114294
