Vaccines may soon effectively help treat people with drug and alcohol addictions.

Scientists in Brazil have developed a vaccine that prevents cocaine users from feeling pleasure from the illicit drug, stopping the cycle of addiction in its tracks.

By stimulating the immune system to react to the drug, the chemicals in cocaine are unable to reach the brain and cause the pleasurable sensations that fuel addiction. Alcohol vaccines may also be on the horizon, adding to the list of treatments for addiction issues that destroy so many lives around the world.

Phase 1 trials of the vaccine to treat cocaine have had a 72 percent success rate in clinical settings, granting interest and approval from regulatory bodies. The drug, Calixcoca, which was developed by Brazilian scientists, prevents users from getting high from cocaine.

Cocaine use can lead to serious cardiovascular damage and mental health issues, and is as much of a societal problem — because of the way addicts impact other people as it is a healthcare issue.

Calixcoca works by triggering the user's immune system to produce antibodies when cocaine molecules are detected in the body, much in the same way antibodies are produced when in contact with a disease-causing virus. These antibodies bind to cocaine molecules in the blood, making them too physically large to pass into the brain's reward system where it can make the user feel pleasure. Cocaine normally causes a high by releasing unnaturally large amounts of dopamine into the user's brain, the same feel-good chemical that is released in day-to-day life when something good happens, however. By intervening in this metabolic process, users will not experience the same incentive to carry on with their addictive behaviors.

The vaccine has only been tested so far on animals, however human studies are in the works.

Researchers have found that Calixcoca protected unborn rat fetuses from the effects of cocaine, meaning there is also the potential for human mothers to prevent their children from being damaged by their addiction when they are pregnant.

It is hoped that, alongside social assistance and standard rehabilitation care, the introduction of such vaccines will be a significant tool in preventing deaths from cocaine use.

By reducing the number of addicted users, the demand for cocaine should also shrink, meaning the devastation caused by cartel wars fighting for control of the supply of the illicit substance all over the world could also improve.

Similar medicines exist for alcohol dependence, with products such as Naltrexone having been in use for many years. It works by interfering with the usual way the body metabolizes alcohol, leaving drinkers experiencing an instant hangover after just one drink. The hope is that a vaccine — instead of such medicines — that triggers an immune response can be used in the future to produce fewer side-effects for all addicts.

Countless illicit substances can cause addiction and serious harm, meaning that a new wave of vaccine technologies designed to prevent addiction could soon greatly reduce global suffering from them.