Candidato vaccino contro l’HIV/AIDS, frutto di una collaborazione pubblico-privato tra l’azienda Merck e “HIV Vaccine Trials Network” entra in fase II di sperimentazione. Coinvolto anche il National Institute of Allergy and Infectious Diseases (NIAID), USA.Lo studio è classificato come ‘proof-of-concept’ study, ossia uno studio che deve attestare la prova “di concetto” che il vaccino funzioni. Il vaccino è basato su un vettore di adenovirus, trivalente (MRKAd5 HIV-1 gag/pol/nef), che dovrebbe generare una risposta immuno-cellulare. Si spera che il vaccino possa sia prevenire l’infezione sia contenere la carica virale negli individui che possono infettarsi durante lo studio, essendo essi ad alto rischio di infezione. Lo studio si tiene in 18 siti nel mondo. Il candidate vaccine non può causare infezione da HIV, non contenendo “HIV vivo”.

Study Details

The multicenter, randomized, double-blind, placebo-controlled Phase II trial has begun enrolling volunteers. Additional study sites are awaiting approval, and will be announced as they are approved by their local Institutional Review Boards. The trial seeks to enroll approximately 1,500 male and female volunteers aged 18 to 45 of diverse racial groups who are at high risk for contracting HIV. All study participants will receive counselling about how to reduce their risk of HIV infection.

The study is testing a Merck vaccine candidate – known as the MRKAd5 HIV-1 gag/pol/nef, or trivalent, vaccine – that is based on adenovirus, a common cold virus that has been modified so that it cannot reproduce and cause a cold in humans. The adenovirus is used as a vector, or a delivery vehicle, to transport three synthetically produced HIV genes into the cells. The three HIV genes are known as gag, pol and nef. The delivery of these HIV genes into the cells stimulates the body to generate a potent cellular immune response to HIV, producing an army of killer cells (called T cells) that are programmed to recognize and kill cells infected with HIV. No live HIV is used in the production of the vaccine candidate, so the vaccine candidate cannot cause HIV infection or AIDS.