In this episode Professor Steve Graham talks to Professor Mark Cotton, Department of Paediatrics and Child Health, Stellenbosch University. They discuss his early medical career, as the first paediatric infectious disease specialist in South Africa and one of the first doctors in Africa to treat children with antiretrovirals (ARVs), leading the Children with HIV Early Antiretroviral Therapy (CHER) trial, and current involvement in TB and HIV vaccine trials at Family Centre for Research with Ubuntu (FAMCRU). -- Professor Mark Cotton’s research has focussed on HIV and TB in children. Prof Cotton obtained his undergraduate degree in Medicine from the University of Cape Town; Master’s from the University of the Witwatersrand; and PhD in Immunology from Stellenbosch University. He interned at Groote Schuur Hospital and completed his postgraduate paediatrics training at various South African health facilities. After a Fellowship in Paediatric Infectious Diseases at the University of Colorado, he returned to South Africa to establish the Children’s Infectious Diseases Clinical Research Unit (KIDCRU). He is an Emeritus Professor at Stellenbosch University and advises World Health Organization on HIV in children. He has published/co-published more than 390 peer-reviewed articles in journals such as Lancet and the New England Journal of Medicine. He served on various editorial boards and was president of the World Society of Paediatric Infectious Diseases between 2019 and 2022. He now chairs its Education Committee.