Pubdate: Sun, 14 Nov 1999
Source: Times, The (UK)
Copyright: 1999 Times Newspapers Ltd
Author: Jonathan Leake, Science Editor


IS THIS the last gasp for the tobacco industry? Scientists have come up
with a vaccine that can block the effects of nicotine for up to a year.

The vaccine will initially be targeted at the 85% of smokers who want to
give up the habit. Although the drug would not take away the nicotine
craving, cigarettes would become completely unsatisfying, making it
pointless to smoke them.

The drug could also be used to vaccinate youngsters before they even
started smoking. Most adults who smoke began the habit while in their
teens, so an annual vaccination for those aged 12 to 20 could prevent the
industry recruiting new customers.

"The potential for this kind of drug is huge," said John Shields, senior
vice-president of research at Cantab, the British developers.

Making such a drug available to the public would be a landmark in the
history of vaccines. Until now almost all vaccines have been targeted at
micro-organisms such as viruses and bacteria. It would be the first time
this sort of approach had been used to alter behaviour on such a
potentially large scale.

Vaccination depends on activating the immune system to recognise and
destroy an invading organism or molecule. Previous attempts to develop a
vaccine against nicotine have foundered because the nicotine molecule was
too small to be recognised. The solution adopted by Cantab - and by Nabi, a
rival American firm conducting similar research - is to attach the nicotine
molecule to a much larger one.

Cantab's vaccine uses a protein stripped from the toxin produced by cholera
bacteria. The protein is known to be safe because it is the basis for the
cholera vaccine.

Between one and four nicotine molecules are attached to each protein
molecule, making them large enough for the body's defences to recognise
them as a hostile invader.

Once alerted, the immune system starts to make antibodies specifically
targeted for nicotine. They then bind to every nicotine molecule they can
find and destroy them.

It means that hardly any nicotine can pass from the blood into the brain
where it would normally have its effect.

Cantab has already started tests using a trial version of the vaccine and
plans full-scale trials early next year. A similar vaccine, aimed at
helping cocaine addicts, is already well into its final trials.

Frank Stonebanks, a spokesman for Nabi which is about to commence similar
trials, said he foresaw a day when parents would get their children
vaccinated against smoking in the way that most are inoculated today
against tuberculosis.

"Such drugs would also have huge potential in the Third World where tobacco
addiction costs people a much bigger proportion of their income," he said.

Both companies emphasise that it will be at least three years before a
vaccine becomes widely available. It would probably be used in conjunction
with behavioural therapy since many smokers light up for social reasons as
well as addictive ones.

The development coincides with a sharp increase in smoking among
youngsters. In the past three decades the number of smokers has been
falling steadily but the mid-1990s saw a gradual increase in the number of
child smokers, especially teenage girls.

Government figures show that every day about 450 British youngsters start
smoking while another 330 adults die from tobacco-related illnesses such as
lung cancer and heart disease. Half of all smokers in Britain die
prematurely because of their habit.

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