Koleka Mlisana’s career in microbiology started with something small. More than three decades in the field later, the decision she downplays as a small sacrifice led to her being one of the scientists at the forefront of South Africa’s stand against the HIV and Aids epidemic, and now the Covid-19 pandemic. Born in Mthatha 59 years ago, the new co-chair of the ministerial advisory committee (MAC), the brains trust advising the government on the country’s response to Covid-19, got into medicine because “there were very few options to choose from” at the time. “If you were doing well in maths and science or biology, then it was, ‘Oh, you must go to Wentworth,’ which was the medical school back then.”