The Omicron variant of the coronavirus has also reached the United States. The CDC health agency has identified the potentially more contagious variant in California in a traveller who returned from South Africa on Nov. 22.
The variant had already surfaced in Canada. The mutant has also been found in Europe and other parts of the world.
Omicron has been reported by at least 23 countries in five of the six regions into which the World Health Organization (WHO) has divided the world. According to experts, that number will continue to increase.
The person diagnosed with Omicron in the US was fully vaccinated and had mild disease symptoms, but is improving. After a period of self-isolation, this individual tested negative, as did the close contacts they had.
The US wants to oblige international travellers to take a corona test at least one day before departure.