Vaccines for drug addiction show promise

Getting off drugs may soon be as painless as getting a shot.

The same type of scientists who brought the world vaccines against diseases like polio, smallpox and diphtheria have turned their attention in recent years to developing a shot that can release people from the grip of substance abuse. And they're getting close.

Like a preventative vaccine, vaccines designed to fight substance abuse introduce a small amount of the foreign substance into the blood. The immune system creates antibodies that will attack the substance the next time it appears, the New York Times reported. Unlike a preventative vaccine, the shot is administered after someone has already gotten hooked on drugs. After getting the vaccine, a drug user would be unable to feel high.

Researchers at The Scripps Research Institute have developed a vaccine that, when given to rats, blunts the effects of heroin, according to Science Daily. Rats who received a shot were less likely to "self-administer" heroin by pressing on a lever than those who did not.

"We saw a very robust and specific response from this heroin vaccine," said George F. Koob, chair of the Scripps Research Committee on the Neurobiology of Addictive Disorders. "I think a humanized version could be of real help to those who need and want it."

Human clinical trials are under way for similar vaccines for cocaine and nicotine.

During clinical trials for a cocaine vaccine in Houston, 70 percent of people who received the vaccine developed enough antibodies to block up to two doses of the drug. Forty percent of people using the treatment couldn't get high or overdose no matter how much cocaine they took.

"We had people who in the study came back with urine metabolism levels that were 10 times higher than anyone I had ever seen who was dead, much less alive," Thomas Koston, of Houston's Michael E. DeBakey VA Medical Center, told The Houston Chronicle.

Scientists are still getting less-than-consistent results in human trials, though, the New York Times reported. During a Scripps clinical trial for a nicotine vaccine this summer, people receiving treatment and people receiving a placebo quit smoking at the same rate.

"It's like having the carrot right in front of the horse," said Dr. Kim D. Janda, a professor at the institute. "The big problem plaguing these vaccines right now is difficulty predicting in humans how well it's going to work."

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