COLUMBIA, S.C. (AP) — A new variant of the coronavirus has emerged in the United States. The new version poses yet another public health challenge in a country already losing more than 3,000 people to COVID-19 every day. The mutated virus was first identified in South Africa before being found in two cases in South Carolina. State public health officials say it’s almost certain that there are more infections that have not been identified yet. They are also concerned that this version spreads more easily and that vaccines could be less effective against it. The two South Carolina cases do not appear to be connected.