Anti-Cocaine Vaccine Shows Promise in Mice
There may be a new way to develop a vaccine for people affected by cocaine addiction, the results of recent research indicate.
Addiction specialists and other health professionals have zero reliable medication-based options when it comes to the treatment of cocaine addiction. For decades, scientists have attempted to create a viable cocaine vaccine. In a study published in December 2014 in the American Chemistry Society journal Molecular Pharmaceutics, American researchers from The Scripps Research Institute examined the effectiveness of a new approach to the creation of such a vaccine. These researchers believe their approach increases the likelihood that scientists will develop a vaccine-based treatment for cocaine addiction and other forms of addiction.
Cocaine Addiction and Treatment
As a mind-altering stimulant drug, cocaine can alter the chemical makeup of a portion of the brain called the pleasure center when consumed repeatedly over time. In turn, cocaine-triggered alteration of the pleasure center can lead to enduring changes in brain function that promote the onset of physical cocaine dependence. Functionally speaking, the physical need for cocaine that characterizes a dependent state differs very little from uncontrolled cocaine addiction, which is marked by such problems as strong urges for further drug intake, indiscriminate use of cocaine in dangerous situations, rising tolerance to the mind-altering impact of any given cocaine dose and the development of a withdrawal syndrome when the pleasure center does not receive the amount of the drug it has come to expect.
Despite general advances in the medical treatment of substance addiction, researchers have not found or created a medication capable of reliably helping people affected by cocaine addiction (which is a subtype of a larger condition called stimulant use disorder). Many people in treatment for cocaine use respond well to non-medication-based options such as cognitive behavioral therapy and contingency management, two psychotherapeutic approaches that emphasize real-world changes in thought and behavior. However, some individuals do not respond well to these options, and researchers continue to look for medication-based treatments.
The Cocaine Vaccine Concept
Broadly speaking, vaccines work by giving the human immune system the ability to recognize and preemptively attack microorganisms capable of producing significant declines in health and well-being. The vaccine model has been used successfully to vastly reduce our susceptibility to contagious and potentially deadly ailments such as influenza (the flu) and the measles. In theory, a cocaine vaccine would work by making the immune system react to the presence of
cocaine molecules in the same way it reacts to influenza or measles viruses. Specialized cells in this system would recognize the presence of cocaine and signal an immune response that effectively eliminates the drug from the bloodstream. While numerous research teams are pursuing a cocaine vaccine, no one has created and tested such a vaccine on a large scale in humans.
A New Vaccine Approach
In the study published in Molecular Pharmaceutics, researchers decided to take a new approach to the creation of a cocaine vaccine. They undertook their work, in part, in response to the acknowledged lack of medication-based options for people in treatment for cocaine addiction. In addition, the researchers took note of the fact that previous efforts at a vaccine had established the possibility of getting the human immune system to identify drugs and other non-living bloodstream invaders.
During the study, the researchers modified a harmless protein normally found in bacteria; the protein under consideration already has a track record of effective use in other types of vaccines. The modification the researchers made was specifically intended to increase the immune system’s ability to react to the presence of cocaine circulating in the bloodstream. After completing their modifications, they injected copies of the protein into a group of mice; they then gave the mice access to cocaine.
The researchers concluded that the modified protein responded to the presence of cocaine much more readily than previous vaccine candidates they had explored. Importantly, they also concluded that the observed response is largely dose-dependent; this means that, up to a certain point, large amounts of cocaine trigger greater immune responses than small amounts of cocaine.
The study’s authors believe their work points toward a previously unexplored method of developing an effective cocaine vaccine. They also believe that the principles behind their approach may ultimately lead to the development of effective vaccines for other mind-altering, addictive substances.