The Partners Demonstration Project is a prospective, open-label cohort study of the delivery of antiretroviral-based HIV-1 prevention to high-risk HIV-1 serodiscordant couples in four sites in Kenya and Uganda. HIV-1 infected partners are offered ART according to the national ART initiation guidelines which, as of 2014, recommend ART for all HIV-1 infected partners in serodiscordant couples, regardless of CD4 count . PrEP is offered to the HIV-1 uninfected partner prior to and for the first 6 months after ART initiation by the infected partner, at which time viral suppression is expected.