Tobacco use is the leading cause of preventable disease in the United States, according to the CDC. If you're a smoker who wants to quit, you've probably tried everything to kick the habit: nicotine patches, e-cigarettes, gum. There may be a new, more effective way to stave off addiction, however. A team of scientists at the Scripps Research Institute is working on an experimental new approach to curbing nicotine addiction.
The scientists, led by Kim Janda, a chemistry professor and a member of the Skaggs Institute for Chemical Biology at Scripps, are developing a vaccine that would tell the body to treat nicotine as a foreign substance, which will keep nicotine from being able to communicate with the brain's "reward" channels.
If the vaccine is successful, smokers would no longer get a high after ingesting nicotine. While withdrawal symptoms would still be present, the researchers hope this would eliminate nicotine's addictive effect and make it easier for smokers to quit.
This is the second time this team has turned to creating a nicotine vaccine. Nicotine has two forms that look like mirror images of each other, Janda explained. One is a "right-handed" version and one is a "left-handed" version, and 99 percent of the nicotine found in tobacco is the left-handed version.
A few years ago, the team tried to develop a vaccine that would target nicotine, but their vaccine was not very effective: it only worked for 30 percent of patients. They persevered, and the team hypothesized that a vaccine which only targets the left-handed form of nicotine, the most common form, would be more effective than the previous vaccine, which worked for both the right-handed and left-handed forms of nicotine. The scientists now believe that targeting two different molecules only created an overall weaker reaction to the vaccine by spreading the immune system too thin.
"This is a case where something very simple was overlooked," Janda said.
To test this theory, the team created three different vaccines and tested them in a group of rats. One vaccine worked for the left-handed form of nicotine, one for the right-handed, and one was a 50/50 mix of each. The left-handed version was much more effective, causing the body to create four times more antibodies than the right-handed version. You can see the dramatic increase in this chart of the team's results.
"This shows that future vaccines should target that left-handed version," said Jonathan Lockner, one of the authors of the paper.
The team also suggested that researchers looking to create vaccines targeting other addicting drugs should consider the structure of the drug's molecules.