Solid vaccine protection against SIV in rhesus monkeys provides proof-of-concept for further evaluation of a novel HIV vaccine approach in humans

Protection against acquisition of fully heterologous, neutralization-resistant SIV was achieved in rhesus monkeys with adenovirus/poxvirus vector-based vaccines. Protection against acquisition of infection required the inclusion of envelope antigens and correlated with the induction of binding antibodies against the Env protein. The vaccines also facilitate virological control in vaccinated animals that became infected, correlating with multiple humoral and cell-mediated immune responses, especially against the Gag protein. These results are discussed in the context of human trials, particularly the Thai RV144 efficacy trial.