Wise AD

Wise AD

Friday, December 28, 2012

'Smoking vaccine' blocks nicotine in mice brains


Man smoking
Researchers believe vaccines may one day help people if they choose to quit.
Smokers could one day be immunized against nicotine so they gain no pleasure from the habit, according to researchers in the US.
They have devised a vaccine that floods the body with an antibody to assault nicotine entering the body.
A study in mice, published in Science Translational Medicine, showed levels of the chemical in the brain were reduced by 85% after vaccination.
Years of research are still needed before it could be tested on people.
However, lead researcher Prof Ronald Crystal is convinced there will be benefits.
"As far as we can see, the best way to treat chronic nicotine addiction from smoking is to have these Pacman-like antibodies on patrol, clearing the blood as needed before nicotine can have any biological effect."
New approach
Other "smoking vaccines" have been developed that train the immune system to produce antibodies that bind to nicotine - it is the same method used to vaccinate against diseases. The challenge has been to produce enough antibodies to stop the drug entering the brain and delivering its pleasurable hit.
Scientists at Weill Cornell Medical College have used a completely different approach, a gene-therapy vaccine, which they say is more promising.
A genetically modified virus containing the instructions for making nicotine antibodies is used to infect the liver. This turns the organ into a factory producing the antibodies.
The research team compared the amount of nicotine in the brains of normal mice with those that had been immunised. After being injected with nicotine, the vaccinated mice had nicotine levels 85% lower.
It is not known if this could be repeated in humans or if this level of reduction would be enough to help people quit.
Prof Crystal said that if such a vaccine could be developed then people "will know if they start smoking again, they will receive no pleasure from it due to the nicotine vaccine, and that can help them kick the habit".
He added: "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."
'Impressive and intriguing'
There are also issues around the safety of gene therapy in humans that will need to be answered.
Professor of genetics at the University of Kent, Darren Griffin, said the findings were "impressive and intriguing with great potential" but cautioned there were still many issues which needed addressing.
He said the main issue "is whether the observed biochemical effects in lab mice genuinely translate to a reduced addiction in humans given that such addictions can be both physical and psychological".
Dr Simon Waddington, from University College London, said: "The technology underpinning gene therapy is improving all the time and it is encouraging to see these preliminary results that indicate it could be used to address nicotine addiction, which is damaging to the nation's health and a drain on the health service economy."
If such a vaccine was developed it could also raise ethical questions about vaccinating people, possibly in childhood, before they even started smoking.
                                            Graphic anti-smoking ad launched
The new Department of Health anti-smoking television advert
series of hard-hitting government adverts featuring people smoking cigarettes with a tumour growing from the end is being launched in England.
The ads will tell smokers that just 15 cigarettes can cause a mutation that leads to cancerous tumours in what marks a return to shock campaigning.
It is eight years since government's "fatty cigarette" anti-smoking adverts appeared.
This £2.7m ad campaign will appear on TV, online and posters until February.
Smokers will also be told about NHS quit kits that are available free from pharmacies.
More than a third of smokers still believe the health risks from smoking are greatly exaggerated, recent statistics from the Department of Health showed.
'Risk'
Chief medical officer Prof Dame Sally Davies said smokers were still underestimating the serious health risks from smoking.
"We want smokers to understand that each packet of cigarettes increases their risk of cancer."
"People will see a man smoking and then a cancer growing out of the cigarette. That is what happens in people's bodies.
"We really want to catch all smokers but particularly the young who won't have seen hard hitting campaigns before. They don't understand what damage is happening in their bodies, what their risks are," she added.
The adverts follow the Stoptober campaign, which saw more than 270,000 sign up in a mass attempt to quit two months ago.
The ad campaign has received the backing of Cancer Research UK.
Its chief executive Dr Harpal Kumar said: "Hard-hitting campaigns such as this illustrate the damage caused by smoking and this can encourage people to quit or may even stop them from starting in the first place."
"Giving up smoking can be extremely difficult, so providing extra motivation and reminding people of just how harmful the habit is can help smokers to take that first step in quitting for good."
The charity said smoking is the single biggest preventable cause of cancer and causes about a quarter of all cancer deaths.

No comments:

Post a Comment