Thursday, June 28, 2012

Nicotine vaccine in the works - Guardian Express

By Luis Cabrera

An innovative approach to help those trying to quit smoking for good may be available in the near future. Scientists at Weill Cornell Medical College are experimenting with a promising new way to combat addiction: a vaccine that provides anti-bodies to block nicotine directly in the blood stream.

The study published in Science Translational Medicine was conducted in mice, and it showed an 85 percent reduction in nicotine’s brain level for test animals that had been injected.

A human version of the promising vaccine may still be years ahead, but the lead researcher in the study, Professor Ronald Crystal, is very optimistic. “The best way to treat chronic nicotine addiction,” he said, is to “have these Pacman-like antibodies on patrol.” The searching cells are said to destroy nicotine present in blood before the alkaloid has any biological effect in the body.

Past versions of the elusive addiction cure, only effective for a few weeks, used the same method for vaccination that is carried against common diseases. Previous attempts tried “training” the immune system to produce anti-bodies that bind to nicotine. However, making the liver create enough antibodies to completely block nicotine’s pleasurable feelings has been a challenge.

Crystal and his team have taken a very different path. They are using a gene-therapy approach, which they believe will have better results. In this case, a genetically modified virus is injected into the liver, which then identifies nicotine as the offender in the bloodstream and creates antibodies to eliminate it. Additionally, one shot worked for the entire life of a mouse.

The professor said that, if the vaccine is later proven successful for humans, it would make people who already want to quit not get any pleasure from smoking. In turn, this lack of gratification would help them quit the habit. “We are hopeful,” he added, “this kind of strategy can finally help millions,” referring to the way in which the vaccine works.

There are questions, however, and it is not sure whether effects already seen on mice will translate to humans. Changes on rodents may be seen by scientist as strictly biochemical, whereas addiction in humans may also have psychological roots. In addition, powerful ethical concerns may come into play later. For example, at what age, if any, people would get the vaccine, and if this would be done as preventive treatment or not amid growing worries in the healthcare system.

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