Nicotine vaccine to help smokers get rid of habit

A team of scientists has designed a promising nicotine vaccine to help smokers overcome their addiction and proven that the structures of molecules used in vaccines are critical.

Researcher Kim Janda from The Scripps Research Institute (TSRI) said that this study provides new hope that one could make a nicotine vaccine that succeeds in clinical trials.

Nicotine vaccines train the body to see nicotine as a foreign invader. To prompt this immune response, scientists have tried attaching nicotine derivatives called haptens to a larger carrier protein used in other approved vaccines. The body reacts to the vaccine by creating antibodies to bind specifically to nicotine molecules. When a person later uses tobacco, the anti-nicotine antibodies stop the nicotine molecules from entering the central nervous system and ever reaching the brain.

Though a vaccine wouldn't be a silver bullet, there would still be withdrawal symptoms and a person may be less motivated to relapse because the brain's reward system could no longer react to nicotine. In the new study, the researchers elicited a more robust antibody response by creating a vaccine from only left-handed nicotine haptens. To do this, they prepared haptens as a 50-50 mixture and as pure right-handed or pure left-handed versions of nicotine, so they could use the two versions together or separately.

First author Jonathan Lockner added that the study shows that future vaccines should target that left-handed version, suggesting there might even be more effective haptens out there. The researchers believe purifying nicotine hapten mixtures is an important and practical step in creating future nicotine vaccines. Janda said considering molecule handed-ness is also critical for developing vaccines against other drugs of abuse, such as cocaine and heroin.

The study is published in the Journal of Medicinal Chemistry.