Hiv, the hope of a vaccine

It is still too early to sing the victory. But at every HIV conference, the mantra was always that: when is the vaccine? Because the therapy that keeps the virus under control is good, and that should be done for life, it's OK Prep, pre-exposure prophylaxis. But of course, a vaccine would be the keystone of what was the first truly global epidemic. For this reason, the news of a study – published in Lancet – that, after being shown to be well tolerated and eliciting a "robust" immune response in healthy subjects and in a kind of macaque, pbades to the next phase, that of safety and efficiency, it is certainly good news. Also because this vaccine has been shown to work by protecting macaques from an infection caused by a virus similar to HIV.

But we come to the results: the clinical trial of this vaccine – one of the 5 who managed to get to the test in 35-year epidemic – involved nearly 400 adults in good 18-50 year old health care from 12 hospitals (Africa, Thailand, USA) using a mosaic vaccine, which takes fragments of different HIV viruses and combines them to stimulate an immune response against a wide variety of forms of HIV. The vaccine was then administered to volunteers, in one of seven combinations and in four doses in 48 weeks, or they received a placebo
"The first results – according to Dan Barouch, director of the Virology Center and research on vaccines administered at the Beth Israel Deaconess Medical Center, which led the study, should be interpreted with caution, because the effectiveness of a specific immune response to hiv does not necessarily mean that the vaccine protects men from HIV infection. The results of phase 2b of effectiveness – a test we called HVTN705 or Imbokodo – will tell us if this vaccine can actually prevent the infection in men, or better in women, since it will be tested on 2,600 women at risk of contracting the virus.

The study is important – launched Stefano Vella, who heads the Center for Global Health of the Istituto Superiore d i Sanità, who is a big specialist in HIV – but that will not be enough. the most recent approaches that are followed are the others and are followed for any vaccine: identify an antigen that must develop neutralizing anti-occupants, which prevent 100% infection. The vaccine of this study, on the other hand, has been developed to stimulate cellular and non-antibody immunity. It is therefore true that many antibodies are produced but we do not know how effective they are against the virus, which is tricky and cut quickly. Only neutralizing antibodies can block it. And I think we are not far from the first tests on the uninfected. "