Swiss researchers say they have had some encouraging results with an experimental anti-nicotine vaccine.
In a study where 341 smokers were given the vaccine, almost 60 percent stopped smoking for at least six months.
Study leader Jacques Cornuz, of the Centre Hospitalier Universitaire Vaudois in Lausanne, Switzerland, said about a third of those who developed lower levels of antibodies stopped smoking, which was about the same fraction as those who received a placebo vaccine.
According to Cornuz the vaccine, is based on a bacteriophage virus which attacks bacteria. The bacteriophage in the vaccine neutralises the nicotine before it can stimulate the brain.
Cytos Biotechnology, who developed the vaccine, plan to carry out more widespread medical studies to establish the vaccine's safety and hope to bring it on the market around 2010.
The study was presented to a major conference of cancer specialists in Florida on May 15th this year.