The World Health Organization on Friday assigned the Greek letter Omicron to a newly identified Covid variant in South Africa. The U.N. health agency recognized the strain, previously referred to as lineage B.1.1.529, as a variant of concern. Health experts are deeply concerned about the transmissibility of the Omicron variant given that it has an unusual constellation of mutations and a profile that is different from other variants of concern. It is feared a sharp upswing of Covid cases in South Africa’s Gauteng province — where the heavily mutated strain of the virus was first identified — could mean it has greater ... (full story)