rcAd26.MOS1.HIV-Env

rcAd26.MOS1.HIV-Env is an investigational, replication-competent, highly attenuated adenovirus serotype 26 (Ad26) vector vaccine engineered to express a mosaic HIV-1 envelope (Env) protein. The vaccine was designed as a live viral vector to induce durable immune responses against HIV-1 by presenting mosaic antigens that represent diverse global strains of the virus. In phase 1 clinical trials, it was administered orally in healthy HIV-uninfected adults to assess safety and immunogenicity. The single-dose oral administration was well tolerated with only mild to moderate adverse events reported; however, the vaccine demonstrated poor immunogenicity in humans at tested doses, likely due to its highly attenuated replicative capacity[1][2][3][4]. No evidence of viral shedding or secondary transmission was observed.