Treatment Online has an interesting piece on the development of a cocaine vaccine. Unlike other drugs that reduce the pleasurable effect of addictive drugs, this is genuinely a vaccine – it persuades the immune system to attack cocaine molecules.
There are various drugs that are sometimes described conveniently, but inaccurately, as ‘vaccines’ for addictive substances.
For example, disufiram (aka Antabuse) creates a severe hangover 10 minutes after taking any alcoholic drink by inhibiting certain enzymes in the liver which break down alcohol. The idea is that it acts as an instant form of aversion therapy.
A drug called naltrexone blocks opioids in the brain which all pleasurable drugs trigger, either directly (in the case of heroin), or indirectly (in the case of alcohol). Naltrexone simply aims to reduce how ‘fun’ the drug is, leading to extinction of the link between the drug and the ‘high’.
However, neither of these are actually ‘vaccines‘ in the proper sense of the word.
Vaccines are substances that stimulate the immune system. The immune system identifies and adapts to the key features of the potentially dangerous invader, and works to destroy it.
Of course, this happens when foreign pathogens (like diseases) enter the body, but the immune system can be triggered by safe or less dangerous substances that share the ‘key features’ with the more dangerous disease. This safe or less dangerous substance is the vaccine.
Edward Jenner invented the procedure after working out that giving people a tiny amount of the non-lethal cowpox virus vaccinated them against the deadly smallpox virus. In fact, this is where the word ‘vaccinate’ comes from as ‘vacca’ means cow in Latin.
The developers of the new cocaine vaccine, known as ‘TA-CD’, are doing essentially the same thing by cleverly combining a deactivated cocaine molecule with a deactivated cholera toxin molecule.
The deactivated cholera toxin is enough to trigger the immune system, which finds and adapts to the new invader.
Because the cholera toxin and the cocaine molecule are combined, the immune system also adapts to the key features of cocaine, so works out how to seek and destroy cocaine molecules.
This means they never reach the brain in sufficient quantities to cause an effect.
A key advantage is that unlike other anti-addiction drugs, which have to be in the body to have their effect, the cocaine vaccine permanently changes the immune system to neutralise cocaine.
Of course, it may not be completely effective, or it may not work in all people, but that’s the aim.
The drug is about to studied with a Phase III clinical trial to see if it useful in treating cocaine addiction, after which, if it is shown to be safe and effective, it could be approved for widespread use.
Unlike the current concerns about the supposed ‘new ethical challenges’ of medical therapies being used by healthy people (which, as we’ve noted, are actually as old as drugs themselves), this therapy may present a relatively new ethical dilemma.
If effective, you can see that some parents might want to vaccinate their non-addicted, perfectly healthy children, so they are ‘immune’ to cocaine.
The difference here, is that once given, the ‘immunity’ may be permanent. In other words, you would make the decision that your child will never be able to experience the effects of cocaine for the rest of their life.
One interesting effect might be an ‘arms race’ between illicit drug producers and vaccine makers. As children become ‘vaccinated’ against the common drugs of abuse, the market for street drugs would fragment and diversify into drugs that don’t have vaccines yet.
A Brave New World indeed.
Link to Treatment Online on cocaine vaccine.
Link to PubMed papers on cocaine vaccine.
Link to Toronto Globe and Mail article on the vaccine.