TIM COCKS THE students knew their South African university was the epicentre of a new COVID-19 variant spreading panic across the globe, but over the past week, many worried more about how Omicron would mess up exams and holiday plans than about catching it. At the Tshwane University of Technology (TUT), in the capital Pretoria, learners languidly walked across the green campus shaded by trees, chatting, buying soft drinks, staring at their phones and sitting on benches overlooking a pond. Most wore masks; a few didn't. Many were vaccinated; some obstinately were not. Around 30 students interviewed by Reuters were…