John is a Professor Emeritus of Mathematical Sciences at Stellenbosch University and was the inaugural director of the South African Centre for Epidemiological Modelling and Analysis (SACEMA). The precursors for MMED and DAIDD were launched in 2006 at the beginning of his directorship and he has been involved continuously as an instructor in the programme since then. Over the past nearly 50 years John has combined fieldwork and mathematical epidemiology to understand the population dynamics and control of tsetse flies, the vectors of Human African Trypanosomiasis. His current interests are in modelling population dynamics, with a particular focus on how increasing temperatures in Africa will affect tsetse distribution. This work involves improving estimation of mortality in adult and immature stages of the fly. Since 1999 he has also focused on the analysis and modelling of data in the world of HIV. Current interest are in improving the use of biomarkers for the accurate estimation of HIV incidence.