ALVAC-HIV + bivalent gp120 protein

ALVAC-HIV + bivalent gp120 protein is an investigational HIV-1 preventive vaccine regimen consisting of two components used in a prime-boost strategy. The first component, ALVAC-HIV (vCP2438), is a recombinant canarypox viral vector vaccine that expresses HIV-1 env gp120 (subtype C, ZM96.C strain) linked to the gp41 transmembrane sequence, along with gag and protease from the subtype B LAI strain. The second component is a bivalent subtype C gp120 protein boost, combining 100 mcg each of the HIV-1 subtype C gp120 proteins from the TV1.C and 1086.C strains. The regimen is typically adjuvanted with MF59 (a squalene oil-in-water emulsion), alum, or AS01B to enhance immunogenicity. Developed by Sanofi Pasteur in collaboration with the HIV Vaccine Trials Network (HVTN) and NIAID, this regimen specifically targets HIV-1 subtype C, which is prevalent in sub-Saharan Africa. It aims to elicit HIV-specific humoral (binding and neutralizing antibodies) and cellular (CD4+ T-cell) immune responses. While it showed promise in Phase 1/2 trials (HVTN 100), the Phase 2b/3 Uhambo trial (HVTN 702) was stopped early in 2020 due to a lack of efficacy in preventing HIV infection.