Contributed by guest blogger: Jessica Hughes ’11
It is well known that drug addiction is a worldwide problem, and so finding a therapy or cure for this issue would be extremely valuable. Scientists have been trying to create a vaccine for people with drug addictions that would allow them to be rid of their chemical dependence, but there are several challenges they face in trying to do so. First, addictive drugs are small molecules that do not cause an immune response on their own. Furthermore, because of the extremely high level of drugs often found in the blood of a systemic drug user, there needs to be a way to create high-titer, high-affinity antidrug antibodies to address that extremely high drug concentration. This second challenge has limited the effectiveness of many attempts at anti-addiction active immunization strategies.
In a 2010 study, researchers looked at creating an anticocaine vaccine with the help of adenovirus. With the knowledge that inhaled cocaine could not reach its target receptors in the brain when exposed to anticocaine antibodies, researchers looked into the possibility that cocaine addiction could possibly be reversed with an anticocaine vaccine. Here’s where adenovirus came in. Researchers knew that adenovirus gene transfer vectors act as potent immunogens, which provoke adaptive immune responses. They predicted that if they coupled the adenovirus with a cocaine analog, they could elicit high-titer antibodies against cocaine and successfully prevent this drug’s access to the brain. Specifically, they used a disrupted E1-E3- adenovirus gene transfer vector, which means they were able to avoid viral gene products that would pose a risk of infection to the vaccine receiver but still have the benefit of the immunogenic property of the vectors. E1-E3- has been used many times in gene transfer applications, proving to be very safe.
In their experiment, once they created the vaccine (called dAd5GNC), they used mice to test its effects. Both naïve mice and vaccinated mice were given cocaine intravenously, and subsequently their locomotor activity was observed. The administration of cocaine caused hyperlocomotor activity in mice. These effects were completely and consistently reversed for the vaccinated mice. This is a promising result, and further studies obviously need to be done to continue looking into the possibility of using anti-addictive drug vaccines. Some questions to think about: Would an anticocaine vaccine work in the real-life scenario of preventing an addict from relapsing? Could there be dangers with taking these vaccines, such as accidental overdoses of someone trying to obtain the feeling he/she is used to getting from the drug?
The vaccine isnt against addiction per se, but rather against the drug itself. That means that the drug would not have any effect on the user…the drug is neutralized by the antibodies so it can’t generate a high. There would be no point in using the drug because it wouldn’t have any effect.
I don’t really understand how this would be beneficial to drug users. If an anti-cocaine addiction vaccine was invented then people could occassionally abuse hard drugs in ways that would be detrimental to their bodies without making them get clean. In addition, the most addictive part of hard dtugs is the massive release of dopamine or seratonin. If drug users were able to get this feeling without getting addicted, the use of drugs would become much more widespread.
a vaccine might be the first step to “curing” people of cocaine addiction. People take drugs to alleviate stress and pressure in their lives. Until we teach people “coping” skills they will replace “cocaine” with something else that is addictive.
To expand, the anti-addictive drug vaccine would, at the very least, need to be taken in conjunction with some sort of rehabilitation measure (actual rehab, a 12-step program, etc.) Personally, I feel that the costs outweigh the benefits. It’s still a very interesting experiment, and perhaps there are important answers and other possibilities for the future that will come out of this and other similar studies, but at the present moment, I think that other means of getting over addictions would be much more effective in the long-term.
Amelia, I think you raise an interesting question, attached to which are several moral and ethical issues. Personally, I feel there are several issues with an anti-addictive drug vaccine in the first place, one being the idea that this vaccine alone would “cure” an addict. This is not true, and if the vaccine alone was taken as an end-all measure, that individual (if truly an addict) would simply turn to another drug or addiction. All the vaccine would do is “shut-down” the effects of that drug – it would not fix the chemical, emotional, mental wiring in the individual’s brain that makes that person an addict. So, I agree with you that if there was somehow an anti-vaccine vaccine (which seems like it would not be possible), this would be very dangerous…in that addicts could easily go back to old habits. But, my overall point is that even without an anti-vaccine vaccine, there are many other concerns regarding relapsing to other drugs/addictions and overdoses of the drug of choice.
I dont think that an anti-vaccine vaccine to reverse the immunity of the first vaccine would be possible, however, not all vaccines provide life-long immunity. It is possible that immunity would naturally wane over time. That being said, it is possible that exposure to the drug again may serve as a booster, strengthening waning immunity. Or it is possible that without being conjugated to Adenovirus, the drug may not be able to boost immunity. Obviously a lot still to be discovered….
I know we already discussed this in class, but I was thinking about an anti-vaccine vaccine, or some way to reverse the inoculation. Since vaccines are so final, it would probably be difficult to remove the inhibitory effect against the drug, and people might be less likely to get the vaccines if there is no turning back. Similarly, parents might get their kids vaccinated against their will. But making anti-drug vaccines reversible also leads to further moral/ethical questions, such as if the vaccine is reversible, how would it keep addicts from going back to old habits. It will definitely be interesting to see where this line of research leads.