COCAINE VACCINE - TO USE OR NOT TO USE IT?

Although a vaccine for cocaine addiction has been discovered, as with
every scientific discovery it is now up to society to choose whether
to make use of it or not, said Professor Richard Muscat.

Prof. Muscat, Professor of Behavioural Neuroscience at the University
of Malta was commissioned by the Pompidou Group to write a paper
discussing the implications of the TA-CD vaccine.

The Pompidou Group is an inter-government body formed in 1971 that
studies and compares drug use trends in Europe and was instrumental
in setting up the European School Survey Project on Alcohol and other
Drugs (ESPAD Report).

The concept behind the TA-CD vaccine is very simple: cocaine blocks
nerve cells from absorbing dopamine, a chemical substance produced by
the brain that controls pain relief. The blockage creates an
overabundance of dopamine in between nerve cells, leading to what is
known as "a cocaine high."

The TA-CD vaccine makes ingested cocaine attach itself to a larger
protein molecule, while at the same time causing the immune system to
recognise and combat this larger protein molecule before the attached
cocaine is able to reach the brain. The TA-CD vaccine does not
actually stop someone from wanting to consume cocaine, but it does
inhibit the "high".

Studies conducted in the US and in England show promising results:
the vaccine was developed in the UK and was tested on 18 cocaine
addicts over a period of 14 weeks.

According to the results, three quarters of the vaccinated group of
addicts were drug free for a period of three months.

Furthermore, after six months, both those who had relapsed and those
who had not, said that the "high" was not as strong as before taking
the vaccine.

In the US, where studies were funded in part by the US National
Institute on Drug Abuse and which used the largest number of
subjects, patients were able to remain off cocaine for six months.

Additionally, parallel but separate studies indicate that an
individual's pre-existing brain chemistry can increase his or her
predisposition to become addicted to cocaine, opening the door to
prevention strategies that test for this predisposition.

At present there are no medical treatments available for cocaine
addiction, Prof. Muscat said.

The reason appears to be the mechanism of action through which
cocaine exerts its effects on the brain neurotransmitters dopamine
and serotonin.

Heroin binds to brain opioid receptors, such as the mu receptors, and
therefore mimics the action of the brain's own endorphins.

However, cocaine inhibits the reabsorption of dopamine and seratonin,
leading to a build-up of the transmitter, thus prolonging and
strengthening its effect, he explained.

Prof. Muscat said it does not mean that it is not possible to develop
a medical treatment for cocaine addiction - only that it may be more
difficult to do so and may involve different concepts.

Every single organism has a pleasure pathway wired in his or her
brain, he explained. "All a drug does is amplify the feel-good factor."

Furthermore, the TA-CD vaccine does not switch off the craving for
the drug. "What researchers are suggesting is that it is administered
only after the person has undergone rehabilitation."

Prof. Muscat explained that research has found that 50 per cent of
dependent substance abusers may be genetically related.

"Therefore this raises a number of ethical issues such as: do we
administer the vaccine to 10-year-olds who have a predisposition for
substance dependency?" queried Prof. Muscat.

However, even though the vaccine has yet to be approved for the
general population, researchers from around the world are already
raising objections to widespread use of the vaccine on ethical grounds.

In his paper Biomedical research in the drugs field, Prof. Muscat
discusses the ethical issues behind the vaccine.

Should it be used, asked Prof. Muscat, "for example where adolescents
are considered to be at risk of developing cocaine dependency? Do we
vaccinate all young people with increased vulnerability?"

Prof. Muscat pointed out that as not every individual's brain
chemistry reacts to cocaine in the same way, administering a vaccine
indiscriminately would be cause for concern.

However, he added, administering the vaccine to people identified as
having a predisposition to cocaine addiction, might end up stigmatising them.