The role of mucosal anti-HIV IgA in humans is less well studied, although data from the Ugandan trial in uncircumcised men and high-risk Kenyan women linked mucosally produced neutralizing IgA to lower risks of HIV acquisition
Our working hypothesis is that mucus proteins as well as the epithelial tissue environment play key roles in this protection, the mechanism(s) of which need to be elucidated in future studies. The potent protection provided by the mucosally administered nmAbs give impetus to not only induce mucosal antiviral Ab responses of different classes by active immunization, but also to consider further development of topical nmAb prophylaxis in parallel. Lessons learned from the anti-HIV-1 studies will also be of significance for the development of strategies that seek to prevent mucosal transmission of other pathogens.