"We saw both blunting of the drug's effects and, remarkably, prevention of drug lethality.”
A team of scientists at The Scripps Research Institute (TSRI) has developed a vaccine that blocks the pain-numbing and euphoric effects of opioids in mice. By potentially eliminating the “reward” aspect of popular opioids oxycodone and hydrocodone, this vaccine may lower the risk of getting hooked on these highly-addictive rugs.
Throughout the course of the study, the researchers were pleasantly surprised to observe a completely unexpected effect of the new vaccine — it appears to decrease the risk of a fatal opioid overdose, as well.
"We saw both blunting of the drug's effects and, remarkably, prevention of drug lethality," Kim D. Janda, member of the Skaggs Institute for Chemical Biology at TSRI, said in a press release. "The protection against overdose death was unforeseen but clearly of enormous potential clinical benefit."
How does the vaccine work? It harnesses the immune system’s ability to identify invaders and seek them out to destroy them.
The team combined a signature opioid structure with a certain molecule that triggers an immune response. After the vaccine is injected, it teaches the immune system to bind to the drug molecule and eliminate it from circulating through the body.
"The vaccine approach stops the drug before it even gets to the brain," explains study co-author Cody J. Wenthur. "It's like a preemptive strike."
The researchers’ observations showed that the vaccinated mice didn’t display the typical signs of an opioid drug high, like ignoring pain and discomfort.
Although some of the mice did end up dying from toxic opioid effects, the researchers found that, overall, the rodents appeared to be less susceptible to a fatal overdose. Even in the mice that did die, the team noted that it took significantly longer for the overdose to result in death.
Before we get too ahead of ourselves, these results have only been confirmed with mice, which in no way guarantees that they will translate over to humans. However, if further research finds these effects to apply to humans, the vaccine could allow for more time to get medical assistance for an overdose, potentially saving lives.
Another silver lining is that the vaccine remained effective in mice for the entire 60-day study period, and the researchers think it may have the potential to last even longer — but again, these results remain to be seen in humans.
The research appears in the journal ACS Chemical Biology.