The Omicron variant of Covid-19, which had been undetected in the US before the middle of this week, has been discovered in at least five states, showing yet again how mutations of the virus can circumnavigate the globe with speed and ease.

Just a day after the first known US case was found in California, tests showed the Omicron variant had infected at least five people in the New York City metropolitan area, plus a man from Minnesota who had attended an anime convention in Manhattan in late November.

Health officials in each state said there was no cause for undue alarm. But the spread of the cases, some involving people who hadn’t been away from home recently, meant the variant was likely already circulating domestically in some parts of the US.

Read more from AP here.