COCAINE VACCINE TRIALS PROGRESS

Cocaine Produces A Euphoric "High"

Fresh testing of a vaccine which may reduce the "high" experienced by
cocaine users has been launched in the US.

Earlier tests suggested that the vaccine, called TA-CD, can reduce the
euphoric effects of the drug in the majority of patients.

Cocaine is one of the most widely abused drugs in the US and UK.

It has been linked to medical complications such as heart and breathing
problems, and while not as addictive as drugs such as heroin, withdrawal is
associated with strong cravings, depression and anxiety.

At present there are no reliable therapies to help doctors wean users off
the drug, and even in drug treatment programmes, approximately half of all
patients go back to taking the drug.

The drug has its effects on the brain because its molecules are small
enough to slip past the "blood-brain barrier" - a filter which stops
potentially toxic substances reaching the delicate tissues of the brain.

No Fun

The vaccine aims to work by helping the body produce antibodies which bind
to the cocaine molecules, stopping them being taken up by the brain.

This means that, even if a vaccinated patient takes cocaine, the pleasure
associated with the drug will be greatly diminished.

Safety trials of the vaccine have already been successfully completed, and
tests to work out its effectiveness have also yielded positive results.

Four doses of the vaccine was found, over a 12 week period, to lessen the
euphoric effects of the drug in five out of six patients.

Antibodies were detected in the blood for months after the injections.

David Oxlade, the chief executive of Xenova, the pharmaceutical firm
developing the drug, said: "TA-CD has shown considerable promise to date.

"There is a real need for an effective therapy to help habitual cocaine
users to overcome their problems of drug abuse and addiction."

Aidan Gray, a national coordinator for Coca, a support group on cocaine and
crack cocaine issues, told BBC News Online that a successful vaccine could
be a useful tool.

He said: "If it does everything they say it can do, it will be very useful.

"The only questions are how long the effect is going to last, and how much
it is going to cost.

"Will patients need to be given this vaccine periodically for the rest of
their lives?"

The firm is also developing a vaccine using similar principles to combat
nicotine addiction.

This is an earlier testing stage - although anti-smoking campaigners say it
could be of significant help to those battling to quit the habit.