Once the immune system has been “trained” through a series of vaccination shots, it will react to any molecular structures that look like opioids and secrete antibodies that hitch a ride on drug molecules. This prevent them from permeating the blood-brain barrier for as long as eight months.
“The antibody binds to the drug so the drug can’t get to the target,” Janda explained.
Janda made clear that these vaccines don’t cure a drug addiction. “You’re not going to be giving these to kids or people who don’t do drugs,” he says. “This is for people who have problems getting off the drugs, [who] have issues with abstinence, which all addicts have.”
The most likely candidates for these vaccines will be people who have a history of overdoses or unsuccessful attempts to quit the drugs. Phil Skolnick, director of the Division of Therapeutics and Medical Consequences at the National Institute on Drug Abuse, which funded Janda’s work (as well as other similar research), said, “Getting [addicts] to make one good decision every day not to take opiates is a very tough thing to do.” By taking a biologic vaccine, as immune-based therapies are called, targeted to the drug they’re addicted to, “an addicted—and now immunized—person would have an enduring protection. That’s one of the strongest arguments for developing biologics against drugs of abuse,” he said.
Even more crucial, this vaccine has the potential to reduce overdose deaths; the receptors in the brain that give the “pleasure” part of a drug high are the same ones that can slow breathing when a person takes a high dose of the drug. With the vaccine in a person’s system, there’s a better chance even in amounts high enough to induce overdose, a person’s breathing won’t be affected.
While the research is promising, so far these studies, while promising, have only been tested on mice and monkeys. Researchers hope to be able to take them to human clinical trials before long.
“Vaccines are meant to be used by people who want to quit taking drugs,” Janda explained to Philip Ball at The Guardian.
“If you don’t want to stop then nothing will help. The idea is that if they have a moment of weakness, they won’t relapse and can continue with their therapy.”