The vaccine against heroin was tested on primates

Denis Strigun, Naked Science

Specialists from Virginia Commonwealth University and the Scripps Research Institute have developed and conducted preclinical trials of a vaccine against heroin.

The prevalence of synthetic opioids is associated with their persistent analgesic properties. Due to the structural similarity with endorphins, such drugs easily overcome the blood-brain barrier and stimulate mu-opioid receptors (MOR), causing euphoria. However, long-term use of opiates leads to a reduction in the population of such receptors, an increase in resistance and addiction. Therapy of the latter is of a substitutive nature: patients receive inpatient agonists (methadone) or antagonists (naltrexone) MOR. Existing treatments for opioid addiction are relatively expensive, unreliable, and have side effects.

Due to the relatively low cost, pronounced sedative effect and rapid onset of withdrawal syndrome, heroin is considered the most dangerous synthetic opiate. In addition to addiction, injections of this morphine derivative increase the risk of HIV and hepatitis C infection. At the same time, despite being included in the list of prohibited for free circulation, heroin is still used in medicine, for example in the UK in palliative practice, and is often used illegally. In the USA alone, from 2005 to 2015, the number of opiate users doubled to 828 thousand people. Treatment of heroin addiction costs the American budget $ 27 billion.

In a new paper, American scientists have described the results of preclinical trials of a conjugated vaccine to prevent heroin withdrawal syndrome. In the classical version, such a drug is a hybrid carrier protein molecule with a hapten (semi-antigen) and adjuvants. Thanks to the latter, the hapten acquires immunogenicity and, due to its high structural congruence, can bind to the target substance that has entered the body, in particular heroin. In this case, binding occurs on the periphery, and the opiate does not enter the brain. The researchers tested the effects of all the components of the molecule on mice and on four rhesus monkeys (Macaca mulatta).

Article by Bremer et al. The development of a Clinically-Viable Heroin Vaccine is published in The Journal of the American Chemical Society.

Mechanism of action of the anti-drug vaccine

The authors used carboxylic acids (HerCOOH, HerdBA) or thiol (HerSH) as haptens, tetanus toxoid (TT), fisurella hemocyanin (KLH) or diphtheria toxoid (DT) performed the function of a carrier provoking an immune response. The results showed that HerCOOH-TT conjugate prevented heroin analgesia better than others. The addition of the drug with adjuvants – CpG-oligodeoxynucleotide (ODG) and alum (aluminum hydroxide) – increased the activity of heroin antagonists. At the same time, the use of cGAMP as an adjuvant turned out to be ineffective. Within three months, the effect of the vaccine decreased, but could be prolonged by repeated administration.

According to scientists, thus, the tests demonstrated the possibility of forming an immunological memory for the drug. In the near future, they intend to involve commercial partners to test the vaccine on humans.

Portal "Eternal youth" http://vechnayamolodost.ru  08.06.2017