The vaccine will be tested on 164 people at a dozen hospitals during the first half of next year, Carmen Moya Garcia, an epidemiologist who heads the health ministry`s National Plan on Drugs, said today.
It does not eliminate the craving for cocaine but will stop addicts experiencing a high when they take it.
The vaccine causes a protein molecule to be attached to cocaine molecules, which stimulates the body`s immune system to produce antibodies that recognise the drug and prevent it from reaching the brain, said psychiatrist Carlos Alvarz Vara.
"Patients do not feel anything when they consume the drug and become frustrated that they spent their money for nothing," he said.
The clinical trial, which was approved by the European Medical Agency, could be extended to other European countries.
Last year 22,000 Spaniards requested treatment for their addiction to cocaine from hospitals and doctors.
The treatment of cocaine addiction now mostly involves psychiatric counselling and 12-step programs.
Experts say that the typical addict is a young professional male, between the ages of 15 and 34 years old.
Spain is Europe`s main entry point for cocaine from South America, mostly from its former colony Colombia, the world`s top producer of the drug.
Law enforcement officials say the country has also become a key European money laundering centre for Colombian cocaine cartels.
Over 8000 people were jailed in Spain last year in Spain for cocaine trafficking.
