Professor Cotton is an emeritus professor at Stellenbosch University. He undertook a fellowship in paediatric infectious diseases at University of Colorado between 1991 and 1995. He is affiliated to the IMPAACT and PENTA networks and provided technical support for WHO initiatives between 2004 and 2019 on the HIV Classification for HIV, antiretroviral guidelines and TB-HIV co-infection. He was co-PI and investigator in several clinical trials in children, both on ART strategy (CHER) and isoniazid prophylaxis and also ARV pharmacokinetics in children. His special focus now is HIV remission. He is involved in vaccine studies for TB. He is interested in clinical infectious diseases and all aspects of HIV in children and adolescents.
He was president of the World Society of Paediatric Infectious Diseases (WSPID) between 2019 and 2022 and now chairs its education committee.
