In the first of its kind, a vaccination may soon be available for those persons addicted to cocaine, nicotine and heroin to help repress cravings and eventually kick the habit. A lasting anti-cocaine immunity in mice has been discovered by administering a safe vaccine that combines elements of the common cold virus with a particle that mimics cocaine.
In a bi-coastal study funded by The National Institute on Drug Abuse, scientists from Weill Cornell Medical College Cornell University in Ithaca and the Scripps Research Institute in California injected billions of these viral cocktails into non genetically engineered laboratory mice, and uncovered a strong immune response was generated against the vaccine. This newly developed antibody, when put in test tubes, destroys the cocaine’s ability to circulate throughout the system and eventually reach the brain’s pleasure center.
The antibody immune response produced in lab mice by the vaccine binds to cocaine molecules before the drug reaches the brain and prevents any cocaine-related hyperactivity. The vaccine effect lasted for an incredible 13 weeks, the longest time point evaluated.
The research team dissected an adenovirus (common cold) and extracted the components that elicit an immune response and discarded those that produce mal conditions in humans. They then hooked the cocaine analog on to these proteins to make the vaccine. The analog is more stable than pure cocaine itself, thus producing a stronger immunity.
This new treatment method hooks a chemical that is very similar in structure to cocaine onto components of the common cold virus. The human immune system is not only alerted to an infectious virus, but also learns to “see” the cocaine as an intruder as well according to Dr. Ronald G. Crystal, chairman and professor of genetic medicine at Weill Cornell Medical College.
Once the structure of the new intruder is recognized a natural immunity builds to cocaine particles, so any time cocaine is snorted or used in any way antibodies to the substance are quickly produced and the cocaine molecules are engulfed by the antibodies and prevented from reaching the brain.
Dr. Crystal in the Jan. 4 online edition of Molecular Therapy explains:
“The human immune system doesn’t naturally tag cocaine as something to be destroyed, just like all small-molecule drugs are not eliminated by antibodies. We have engineered this response so that it is against the cocaine mimic. Our very dramatic data shows that we can protect mice against the effects of cocaine, and we think this approach could be very promising in fighting addiction in humans.”
The vaccine’s effect on behavior was also measured. Mice that received the vaccine before cocaine were much less hyperactive while on the drug than mice that were not vaccinated. In doses relative to the amounts humans use when partaking in this drug use, the effect was even seen in mice that received repeat doses similar to known usage patterns.
The human response to cocaine is similar to that of the laboratory animal. The cocaine-dependent human prefers it to all other activities and will use the drug until the user or the supply is exhausted. These persons will exhibit behavior entirely different from their previous lifestyle.
Dr. Crystal is aware the vaccine needs to be tested on humans soon, but he predicts that if it works, it will function best in people who are already addicted to cocaine and who are trying to stop using the drug.
He continues:
“While other attempts at producing immunity against cocaine have been tried, this is the first that will likely not require multiple, expensive infusions, and that can move quickly into human trials. There is currently no FDA-approved vaccine for any drug addiction. An approach that works is desperately needed for cocaine addiction, which is an intransigent problem worldwide. There are no therapies now.”
A common myth is that cocaine is not addictive because it lacks the physical withdrawal symptoms seen in alcohol or heroin addiction. Cocaine has powerful psychological addictive properties. The trend in drug abuse in the United States is presently multiple or polydrug abuse, and cocaine is no exception. Cocaine is often used with alcohol, sedatives such as Valium, Ativan, or heroin, as an upper/downer combination. The other drug is also used to moderate the side effects of the primary addiction. A common polydrug abuse problem, seen especially in adolescents, is cocaine, alcohol, and marijuana.
In addition to Dr. Crystal, the study’s authors included Martin J. Hicks, Bishnu P. De, Jonathan B. Rosenberg, Jesse T. Davidson, Neil R. Hackett, Stephen M. Kaminsky and Miklos Toth of Weill Cornell Medical College; Jason G. Mezey of Weill Cornell Medical College and Cornell University in Ithaca, N.Y.; Amira Y. Moreno, Kim D. Janda, Sunmee Wee and George F. Koob of the Scripps Research Institute in La Jolla, Calif.
Written by Sy Kraft, B.A.