UNM scientists have received federal funding to create a combined vaccine against heroin and fentanyl, which may lead to a powerful new tool to fight addiction and potentially lessen the threat of a lethal overdose.
The two-year $1 million grant was awarded under the National Institutes of Health Helping to End Addiction Long-Term (HEAL) Initiative, said researcher Kathryn Frietze, PhD, assistant professor in the Department of Molecular Genetics & Microbiology.
“The goal is to create a combination heroin-fentanyl vaccine,” she said. “We’re going to make variations on heroin and fentanyl that will allow for us to put those drugs on virus-like particles. Then we’ll test those vaccine candidates to see which one works the best.”
Virus-like particles (VLPs) are essentially viruses that have had most of their genetic material removed, rendering them harmless. The process leaves intact the VLP’s outer protein coat, so the immune system still recognizes it as an invader and creates antibodies in response, making for a flexible vaccine platform.
Frietze plans to attach heroin or fentanyl molecules to the surface of the VLPs in hopes of stimulating antibodies that bind to those molecules in the bloodstream, blocking them from reaching the brain and triggering the expected high. That in turn would blunt their intoxicating effects and perhaps help people seeking treatment to quit using and stay clean.
An equally tantalizing possibility is that the vaccines could actually prevent opioid-related drug overdoses, which have reached epidemic levels, she said.
“We don’t know for sure if we are going to protect against overdose,” Frietze said. “It’s kind of a high bar.” The question is complicated, because people may ingest, smoke or inject these substances, creating different levels of exposure in the body, she notes.
“We’re going to look at those different routes of exposure to fully characterize the capability of our vaccine to protect against sublethal exposures, but also looking at lethal overdose amounts to see if we can protect against fatality or prolong the time to death,” Frietze said.
“You could foresee where if somebody overdoses on fentanyl there’s a narrow window of time to get them to medical assistance.”
A vaccine that protects against opioid overdose might also benefit those who may be unwittingly exposed to fentanyl, which is often added to cocaine, MDMA (also known as Ecstasy or Molly) and even marijuana, Frietze said.
The research team also plans to study whether antibodies that attach to heroin and fentanyl molecules might also recognize other opioid drugs that share a similar chemical structure.
“We may get antibodies that bind to multiple drugs,” Frietze said. “It may be really nice if we get cross-reactivity with those.”
The vaccine model has worked in rodents and will soon be tested on non-human primates, she said. “If we get the same sort of quick immune response that we get in mice, our vaccines will probably elicit really high-titer antibodies in humans as well,” she said.
Frietze is a co-investigator on the grant, along with Bryce Chackerian, PhD, professor and vice chair in the Department of Molecular Genetics and Microbiology, and Matthew Campen, PhD, a professor in the UNM College of Pharmacy with expertise in respiratory illness.