His current research ongoing in the sub-Saharan African country of Botswana focuses on delineating causal mechanisms whereby patients with advanced HIV do poorly after ART initiation. The phenomenon of “early mortality” after ART initiation is common among individuals with advanced HIV in many resource-limited settings, yet the effectiveness of ART in patients who suffer early mortality is unknown. Dr. Bisson’s multi-year prospective cohort study of early response to ART and risk of early mortality, recently completed in Botswana, demonstrated how very early virologic and detailed pathogen-specific cellular immune responses relate to risk of early mortality in patients with advanced HIV and active TB. In addition, he has led randomized clinical trials that demonstrated that empiric TB treatment lacks efficacy in HIV/TB and that early ART initiation in adults with HIV and Cryptococcal meningitis (CM) has potentially harmful effects.