HIV vaccine tested in humans showing promising results

More than three decades after the identification of the human immunodeficiency virus (HIV), scientists are still working on the development of a preventative vaccine that can finally end the disease. epidemic, which infects nearly two million people

New research shows that an experimental HIV vaccine regimen is well tolerated and produces robust and comparable immune responses against the virus in healthy adults and adults. rhesus monkeys.

According to the results of this clinical trial Phases 1 and 2a, which involved nearly 400 healthy adults, initiated a Phase 2b trial in South Africa to determine the safety and efficacy of this trial. HIV vaccine candidate efficacy in 2,600 women exposed to the virus

. ] It is one of five experimental concepts of the HIV vaccine that have progressed to efficacy trials in humans, over the 35 years that the global epidemic has been [19659002] The study recruited 393 healthy adults aged 18 to 50 from 12 clinics in East Africa, South Africa, Thailand and the United States between February and October 2015. The volunteers were randomly badigned to receive one of seven vaccine combinations or a placebo, and they received four doses within 48 weeks.

In order to provide broad protection against the many strains of HIV prevalent worldwide, the vaccine contains a mosaic of genetic sequences found among several strains of HIV

To stimulate an initial immune response, each volunteer received an intramuscular injection of Ad26.Mos.HIV at the beginning of the study and again 12 weeks later. The vaccine containing the HIV Env / Gag / Pol "mosaic" antigens was created from numerous strains of HIV, administered with the aid of a non-replicative common cold virus (Ad26).

To increase the level of response In the body's immune system, volunteers received two additional vaccines at weeks 24 and 48 using various combinations of Ad26.Mos.HIV or a different vaccine component called Modified Vaccinia Ankara (MVA ).

The results showed that all diets. Proven vaccines were able to generate immune responses against HIV in healthy individuals and were well tolerated, with a similar number of reported local and systemic reactions in all groups, most of which were of mild to moderate intensity.

In a parallel study, the researchers evaluated the immunogenicity and protective efficacy of the same vaccine regimens in 72 rhesus monkeys, using a series of repeated challenges with the human immunodeficiency virus Simian (SHIV), an HIV-like virus that infects monkeys.

The Ad26 / Ad26 plus gp140 candidate vaccine induces the highest immune response in humans and also offers the best protection in monkeys, which results in complete protection against SHIV infection in two-thirds of vaccinated animals

The researchers note that although there is no guarantee, there are reasons to be optimistic.

Reference: Evaluation of an HIV-1 Vaccine Mosaic in a Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase 1 / 2a (APPROACH) Clinical Trial and in Rhesus Monkeys (NHP 13-19). The Lancet, 2018. https://doi.org/10.1016/S0140-6736(18)31364-3