The lineage is named BA.2.86, and has been detected in the United States, Denmark and Israel, the CDC said in a post on messaging platform X.

"As we learn more about BA.2.86, CDC's advice on protecting yourself from COVID-19 remains the same," the agency said.

The World Health Organization (WHO) earlier on Thursday said in a post on X that it had classified BA.2.86 as a "variant under monitoring" due to the large number of mutations it carries.

The WHO said that, so far, only a few sequences of the variant have been reported from a handful of countries.