SISIPHO SKWEYIYA AT an emergency COVID-19 ward run by a charity in southern Johannesburg, medics wheel gasping patients to their beds, rush from room to room with oxygen cylinders and pat the back of someone in the grip of a coughing fit. The scenes in the converted community hall are a reminder of how badly South Africa has been hit by its third and most debilitating COVID-19 wave yet, as the infectious Delta variant surges through a mostly unvaccinated population. "The Delta variant has caused enormous strain on the resources ... Every hospital is getting strained, every healthcare worker is…