Deenan is an academic clinical virologist with a research and clinical interest in HIV transmission, antiviral therapy and drug resistance. He was he previously Head of the Division of Infection and Immunity and Professor of Virology at University College London (UCL). He was appointed by the Wellcome Trust as the Director of the Africa Centre for Population Health Studies in 2013. He is seconded from UCL, where he remains Professor of Virology, and is also Professor of Virology at the University of KwaZulu Natal. He has held a number of senior scientific roles, including as Director of the UCL Biomedical Research Centre.
His research work focuses on HIV virus evolution, in particular how HIV escapes drug selective pressure. It spans wet (genomic, phenotypic) and dry (bioinformatics) laboratory approaches, as well as linking in vitro data to national and international population estimates. Deenan led the virology work in the pivotal MRC-funded DART trial of antiretroviral therapy in Africa to estimate the impact of drug resistance on the efficacy of treatment rollout in endemic areas, feeding into WHO guidelines. He is PI on the BMGF Pangea_HIV consortium which maps HIV transmission dynamics in the African generalised epidemcis, through full length viral sequencing. He is also PI on the ANRS Treatment as Prevention Trial, based at the Africa Centre for Population Health.