A new vaccine successfully blocks nicotine addiction in mice, CBS News reports. The vaccine creates antibodies against nicotine. These antibodies target nicotine cells, preventing them from reaching receptors in the brain that provide the pleasurable feeling associated with smoking.

Previous vaccines designed to block nicotine addiction have created antibodies that disappear within a few weeks, the news report notes. The new vaccine contains a virus made from a genetic sequence engineered from a nicotine antibody. It was injected in the liver, where it continually produced nicotine antibodies.

In the study, all of the mice were given nicotine, but only one group of mice received the vaccine. In mice given the vaccine, little of the nicotine reached the brain. The mice were as active after receiving the vaccine as they were before. In contrast, mice given nicotine without the vaccine were more relaxed, and their blood pressure and heart activity were reduced. These signs indicated the nicotine had reached the brain and cardiovascular system.

The vaccine will be tested in rats and primates before being given to humans, according to lead researcher Dr. Ronald G. Crystal of Weill Cornell Medical College in New York City. Human trials are likely within several years, he said.

“While we have only tested mice to date, we are very hopeful that this kind of vaccine strategy can finally help the millions of smokers who have tried to stop, exhausting all the methods on the market today, but find their nicotine addiction to be strong enough to overcome these current approaches,” Dr. Crystal said in a news release.

The study appears in Science Translational Medicine.