WHO chief scientist Dr Swaminathan said reinfections with the Omicron variant 90 days after the virus first strikes are three times more common. While data on the virulence and transmissibility will take time, scientists know that Omicron is a dominant strain in South Africa. They have said there was no surge of re-infection during either the Beta or Delta waves, despite laboratory studies suggesting those variants had the potential to evade some immunity. But they are now detecting a spike in re-infections and the timing suggests the Omicron variant is the driving force. Prof Juliet Pulliam, from Stellenbosch University, said, ‘These findings suggest that Omicron's selection advantage is at least partially driven by an increased ability to infect previously infected individuals.’ However, it is still only one piece of the puzzle. See