A vaccine to help smokers break their nicotine addiction and prevent non-smokers from ever getting hooked could be moving closer to reality.
Researchers say they have developed a vaccine that can protect mice for life against nicotine addiction.
Though the shot has so far been only been tested in mice, its developers are confident it will work in humans too.
The vaccine works by prompting the body to manufacture an antibody that is attracted to nicotine. The antibodies then move around the bloodstream, soaking up nicotine and preventing it from reaching the reward centres of the brain.
"As far as we can see, the best way to treat chronic nicotine addiction from smoking is to have these Pacman-like antibodies on patrol, clearing the blood as needed before nicotine can have any biological effect," the study's lead investigator, Dr. Ronald G. Crystal, a professor of genetic medicine at Weill Cornell Medical College, said in a statement.
Researchers have tried before to vaccinate people against nicotine with anti-nicotine antibodies. But the antibodies disappeared after only a few weeks, so the vaccines ultimately failed.
This time, researchers turned to gene therapy and used the shell of a cold virus to ferry in genes to tell the body to make the nicotine antibody.
The genes also had “instructions” to harmlessly infect the mice’s livers so they could turn the organ as a factory to continuously churn out more antibodies.
The work, by researchers at Weill Cornell Medical College, is described in the journal Science Translational Medicine.
A few weeks after giving the mice the vaccine, the researchers tested it by injecting the mice with the same amount of nicotine as found in two cigarettes. They found that the antibodies in the mice’s blood bound to the nicotine and prevented it from getting to the brain.
"Our vaccine allows the body to make its own monoclonal antibodies against nicotine, and in that way, develop a workable immunity," Crystal said.
The researchers say that a single dose of the vaccine was enough to confer lifetime immunity to nicotine addiction in the mice.
But they add they have yet to see whether the results will translate to humans.
"While we have only tested mice to date, we are very hopeful that this kind of vaccine strategy can finally help the millions of smokers who have tried to stop, exhausting all the methods on the market today, but find their nicotine addiction to be strong enough to overcome these current approaches," he said.
