Nov. 7, 2007 (Orlando, Fla.) -- A shot in the arm may some day help smokers kick the habit.
In a new study, nearly three times as many smokers given an experimental vaccine against nicotine quit for one year, compared with those given a placebo.
The vaccine is called NicVAX. It triggers the production of antibodies that seek out and bind with nicotine molecules in the blood. That makes them too big to cross the blood-brain barrier and get into the brain, where they produce their stimulatory effect.
In theory this will prevent the highly addictive buzz that smokers crave, Gordon Tomaselli, MD, tells WebMD. Tomaselli, chief of cardiology at Johns Hopkins University School of Medicine in Baltimore, was not involved with the research.
"When you smoke, you won't get any satisfaction," he says.
Most other smoking cessation aids work differently. "Nicotine patches and gum actually give you nicotine, the idea being to prevent withdrawal," he says.
Nicotine Vaccine Study
The study involved 310 adults who smoked an average of 24 cigarettes a day. They were given four or five shots of the vaccine or a placebo over a six-month period. Two doses of NicVAX were tested.
Participants didn't know what dose they'd gotten or if they'd gotten the placebo. One year after their first shot, 16% of those given five shots of the higher dose reported they had quit and were still cigarette-free, compared with 6% of those on placebo.
People with the strongest immune responses had the best quit rates, indicating the vaccine was working like it was supposed to.
Eight percent of smokers who had a lower level of the antibody in their system quit smoking in the same period.
Side effects were generally similar in the vaccine and placebo groups. The most frequent adverse events included colds, headaches, and infections of the upper respiratory tract.
The findings were presented at American Heart Association Scientific Sessions 2007.
While they were not directly compared, researcher Stephen I. Rennard, of the University of Nebraska Medical Center in Omaha, says the vaccine's quit rates are comparable to those associated with other smoking cessation aids.
"Some people prefer a shot and some people will do anything to avoid one," Rennard says. "It's important to have options."
The next step: A study, presumably of the higher, five-dose schedule, pitting the vaccine against placebo in larger numbers of people, he says. NicVAX could be on the market in as few as one or two years, he says.