Durable protection against repeated penile exposures to simian-human immunodeficiency virus by broadly neutralizing antibodies.

Penile acquisition of HIV accounts for most infections among men globally. Nevertheless, candidate HIV interventions for men advance to clinical trials without preclinical efficacy data, due primarily to a paucity of relevant animal models of penile HIV infection. Using our recently developed macaque model, we show that a single subcutaneous administration of broadly neutralizing antibody (bNAb) 10-1074 conferred durable protection against repeated penile exposures to simian-human immunodeficiency virus (SHIVSF162P3). Macaques co-administered bNAbs 10-1074 and 3BNC117, or 3BNC117 alone, also exhibited significant protection against repeated vaginal SHIVAD8-EO exposures. Regression modeling estimated that individual plasma bNAb concentrations of 5 μg ml−1 correlated with ≥99.9% relative reduction in SHIV infection probability via penile (10-1074) or vaginal (10-1074 or 3BNC117) challenge routes. These results demonstrate that comparably large reductions in penile and vaginal SHIV infection risk among macaques were achieved at clinically relevant plasma bNAb concentrations and inform dose selection for the development of bNAbs as long-acting pre-exposure prophylaxis candidates for use by men and women. Here, using a repeat-exposure penile SHIV infection model in macaques, the authors show that a single subcutaneous administration of a broadly neutralizing antibody (bNAb) exerts long-acting protection against both penile and vaginal virus exposure, which highlights bNAbs as a potential therapeutic for LA-PrEP.