VACCINE AIMS TO HELP FIGHT COCAINE ADDICTION

Treatment That Eliminates the High Could Be Dangerous

Scientists may have created a vaccine against cocaine addiction: a
series of shots that changes the body's chemistry so that the drug
can't enter the brain and provide a high.

The vaccine, called TA-CD, shows promise but could also be dangerous.
Some of the addicts participating in a study of the vaccine started
doing massive amounts of cocaine in hopes of overcoming its effects,
said Thomas R. Kosten, the lead researcher on the study, which was
published in the Archives of General Psychiatry in October.

"After the vaccine, doing cocaine was a very disappointing experience
for them," said Kosten, a professor of psychiatry and neuroscience at
Baylor College of Medicine in Houston.

Nobody overdosed, but some had 10 times as much cocaine coursing
through their systems as researchers had encountered before, Kosten
said. Some of the addicts reported to researchers that they had gone
broke buying cocaine from multiple drug dealers, hoping to find a
variety that would get them high, he said.

Of the 115 addicts in the study, 58 were given the vaccine,
administered in five shots over 12 weeks, while 57 received placebo
injections. Six people dropped out before the end of the study.

The researchers recruited the participants from a methadone-treatment
program in West Haven, Conn., which made it possible to track them for
the full 24 weeks of the study. The patients were addicted to cocaine
and heroin; TA-CD is designed to work only on cocaine, including the
crack form of the drug.

Like disease vaccines, TA-CD stimulates a person's immune system to
produce antibodies. Of those who received all five vaccine injections,
38 percent reached antibody levels that were high enough to dull
cocaine's effects. The antibodies stayed active for eight to 10 weeks
after the last shot.

In the high-antibodies group, 53 percent stayed off cocaine more than
half the time once they had built up immunity. That compares with 23
percent of those who produced fewer antibodies. The researchers
monitored cocaine use through regular urinalysis.

"In this study, immunization did not achieve complete abstinence from
cocaine use," Kosten said. "Previous research has shown, however, that
a reduction in use is associated with a significant improvement in
cocaine abusers' social functioning and thus is therapeutically
meaningful."