A new nicotine vaccine that has proven safe and well-tolerated results in increased nicotine abstinence when taken at higher doses. The vaccine works by triggering the production of antibodies that bind to nicotine, thereby creating a complex too large to pass through the blood-brain barrier. In an effort to test the safety of an experimental nicotine vaccine known as NicVAX, 68 smokers randomly received a placebo or 50-, 100-, or 200-microgram doses of the vaccine. Doses were administered on days 0, 28, 56, and 182, and participants were followed for 38 weeks. Patients were not instructed to quit smoking unless they felt like quitting. Of the 56 people who completed the study, 6 people taking the highest dose abstained from smoking for 30 days, compared with only one taking the 100-microgram dose, none taking the 50-microgram dose, and 2 participants taking the placebo. Those taking the highest dose also took the least amount of time to achieve 30-day abstinence. Side effects, which were mild, were the same for those in the NicVAX group and for those taking the placebo. Researchers anticipated withdrawal symptoms and cravings as side effects, but no one reported these symptomswhich may have been due to the gradual increase in antibody concentrations.
Ms. Farley is a freelance medical writer based in Wakefield, RI.