Experimental Smoking Vaccine Shows Promise

Clinical trials indicate that an experimental vaccine is showing early signs of effectiveness in helping people stop smoking, Peer View Press reported Sept. 7.

Scientists said NicVax, a nicotine conjugated vaccine, appears to effectively block inhaled smoke from crossing the blood-brain barrier.

Nabi Biopharmaceuticals in Rockville, Md., developed the vaccine, while the trials were conducted by Edwin Wagena, M.D., a health scientist at Maastricht University in the Netherlands.

For the study, 18 healthy smokers and six non-smokers were injected with a 100mcg dose of the vaccine on days 0, 14, 28, and again at six months. A group of three smokers and three nonsmokers received a placebo.

Researchers measured the concentration of antibodies the body produced in response to the vaccine, as well as nicotine concentrations in the blood and the nicotine marker cotinine in the urine. Overall, the researchers found that the levels of nicotine in the blood stream following the injections increased eight-fold by the end of six months, while the amount crossing the blood-brain barrier decreased by 75 percent.

According to Wagena, the vaccine caused the body to produce immunoglobulin G (IgG) antibodies that bind to the inhaled nicotine. This resulted in an antigen/antibody complex that was too large to cross the blood-brain barrier.

A key finding of the study, said Wagena, is that smokers taking part in the study didn't increase their smoking to compensate for no longer getting a big dose of nicotine from each cigarette.

Wagena said additional studies are being conducted in the United States to find different dosing schedules for the drug. The proper dosing schedule will assist clinicians in determining when to initiate and end therapy.

Source: www.jointogether.org