Cocaine and nicotine vaccines show promise

By Eileen McGaurin

The world is uncomfortably full of addicts. In the United States alone, there are an estimated 43.4 million people addicted to nicotine, 2.5 million to cocaine, 1.5 million meth and 900,000 heroin addicts.

After years of research and millions of dollars in failed treatments, science may be on the verge of tackling the perplexities of addiction through the use of vaccines.

Working with, and around, the brain, scientists are finding results in the development of vaccines to treat addiction to smoking, cocaine, heroin and methamphetamines.

Results of a cocaine vaccine study released today, proved effective in 38 percent of study participants. Though effects of the vaccine wore off after two months, according to HealthDay, scientists still say the results are promising.

"The concept works," said Dr. Thomas R. Kosten, leader of the study and professor at Baylor College of Medicine. "There are lots of ways to to engineer it after that to make it work better."

The cocaine vaccine is intended to use the immune system to help block the drug's euphoric effects on the brain, the powerful mechanism that keeps people addicted to drugs, including nicotine.

"The results of this study represent a promising step toward an effective medical treatment for cocaine addiction," said Dr. Nora Volkow, director of the National Institute on Drug Abuse.

Currently there is no FDA-approved medication to fight cocaine addiction and this vaccine offers a "valuable new approach" to the problem, said Volkow.

The vaccine is not a panacea, said Kosten, as it depends on the levels of antibodies that it achieves in each individual case. Those who reach the highest levels of antibodies are more likely to kick the cocaine habit.

"That's the biggest problem with this vaccine," he said. "It is a first generation and it does not create antibodies in everybody. Twenty five percent of the people who get the vaccine do not make much antibody responses."

Kosten said the drug will not prevent cocaine cravings, but can act as a way to prevent relapses for those who want to quit.

"This is a relapse prevention medication," he said. "If you take cocaine, you won't feel anything."

Work is also underway to develop NicVax, a vaccine to stop nicotine receptors in the same way the cocaine vaccine works.

Last week, Nabi Pharmaceuticals of Rockville, Md., was awarded a $10 million grant from the National Institute on Drug Abuse towards a Phase 3 clinical trial of a vaccine designed to prevent relapses among smokers.

The first large trial of an anti-smoking vaccine, this is the final step before the vaccine can be approved for general use.

The vaccine stimulates production of antibodies that bind to nicotine in the bloodstream making them too large to enter the brain. As with the cocaine vaccine, the NicVax would prevent the user from feeling the euphoric effects of nicotine.

While early evidence suggests that the antibodies would remain for only six to 12 months, researchers say that my be long enough to get through the hardest part of quitting -- withdrawal.

The cocaine vaccine study was done by Yale researchers and the National Institutes of Health and appears in the current issue of Archives of General Psychiatry.