1 / 7The world's next major Covid variant is poised to be more severe than the mild strains that are currently world-dominant, according to a new study. The ultra-infectious Omicron strain emerged almost exactly a year ago and its mutated spinoffs have risen to the top in virtually every country in the world.2 / 7They are far milder than the older versions of the virus and many researchers believed they represented a kind of end game for Covid’s evolution, which like many viruses before it, mutate to be more mild so they can spread more easily. 3 / 7Over time, the virus evolved to cause more cell death and cell fusion, leading to increased inflammation in the lungs.4 / 7 These effects more closely resembled those of the ancestral Covid strain than the Omicron strain, according to Professor Alex Sigal, the virologist who led the study. 5 / 7The patient studied is one of the longest known sufferers of Omicron, which itself is widely believed to have evolved in someone with a severely weakened immune system.6 / 7China's draconian 'zero-Covid' policy has driven economic hardship and residents back into isolation. Cases have doubled within a fortnight across the country, where the pandemic began almost three years ago.7 / 7The latest study was carried out by researchers from the Africa Health Research Institute in the South African city of Durban, which was the first lab to test the original Omicron against the older vaccines and show that strain significantly weakened their effects.