Nicotine vaccines

Cigarette smoking is one of the leading causes of death in the world by inducing tobacco-related diseases. Addiction is caused by a chemical called nicotine, and like most drugs, nicotine acts on dopamine receptors and causes more dopamine to be released. Scientists predict that by preventing nicotine from triggering the release of dopamine in the brain, cigarette smoking can be ceased and relapse would be less likely. The way that they tried to go about this is by developing a vaccine, where antibodies bind to the nicotine molecules and making them too large to cross the blood-brain barrier, thus preventing the release of dopamine. To test this vaccine, a clinical trial is necessary. Thousands of smokers or recent ex-smokers were randomly assigned to either take the vaccine or a placebo. There were four different trials that were done, with each one having a different vaccine. Each trial also had different methods of giving the vaccine a certain number of times over a certain number of months. The results of the trials showed a slight difference in cessation rates at 12 months, however they were not significantly different. There was also a risk that the fact that no nicotine was getting to the brain would cause the people involved in the study to smoke more cigarettes to compensate, but none of the trials showed any indications of increased numbers of cigarettes smoked. Different variables were taken into account, such as age, gender, weight, antibody titer, cigarettes smoked per day, and duration of smoking. The only variable that made a difference to the cessation rate was the antibody titer. This information is crucial for future vaccine development so that someday, a vaccine like this would be possible. Apart from the body’s reaction to the nicotine, I think that tobacco addiction also has a slight psychological aspect to it, and in order to completely quit smoking, there should be a specific mindset that smokers need to be in. 

Source: http://onlinelibrary.wiley.com.ezaccess.libraries.psu.edu/store/10.1002/14651858.CD007072.pub2/asset/CD007072.pdf?v=1&t=hi12kpij&s=619ea124dfb4a56befa3056b3e5919f65c9b2931