Cigarette smoking is a common addiction, largely thanks to nicotine. When inhaled, nicotine passes across the alveoli in the lungs, into the bloodstream, and reaches the brain. There, it results in the production of dopamine, which induces pleasure, reduces stress, alters blood pressure and heart rate, heightens alertness and increases information-processing ability in the smoker. But smoking cigarettes also can cause severe health problems, including chronic obstructive pulmonary disease and lung cancer, and is associated with increased risk of cardiovascular disease and non-lung cancers. Smoking-related health care costs top $190 billion per year in the US, and cigarette smoking accounts for one of every five deaths in the US.

Current strategies for smoking cessation are largely ineffective; an estimated 70–80% of attempts result in a return to smoking within 6 months. But now, researchers at Weill Cornell Medical College (New York, NY) led by Ronald G. Crystal have developed a new vaccine that successfully protected mice against nicotine addiction for their entire lifetime with just a single dose. It remains to be determined whether their results will translate to human studies.

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Previous attempts to produce vaccines that use antibodies to bind nicotine in the blood, preventing it from entering the brain, have proven ineffective in clinical trials. These vaccines directly delivered the nicotine antibodies, which persist for only a few weeks and thus require repeated injections. Crystal's team took their vaccine one step further. Instead of delivering the antibodies themselves, their vaccine uses an adenoviral vector to deliver the genetic sequence of an engineered nicotine antibody to liver cells, where it is inserted into the DNA of the cells, enabling them to produce the antibodies. When the researchers administered the vaccine to mice that were also given nicotine injections, the antibodies bound >80% of the nicotine before it reached the brain (Sci. Transl. Med. 4, 140ra87; 2012). The liver cells continued producing antibodies for at least 18 weeks.

“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,” Crystal said in a press release. “Our vaccine allows the body to make its own monoclonal antibodies against nicotine, and in that way, develop a workable immunity.” Crystal's group is planning to test the vaccine in rats and then in primates before proceeding to clinical trials.