The NB.1.8.1 COVID-19 variant was linked to a large surge of hospitalizations in parts of Asia earlier this year.

A new COVID-19 variant called NB.1.8.1, aka "Nimbus," is spreading rapidly in the United States, CDC data show. What to know about symptoms and vaccines.

The World Health Organization (WHO) is keeping an eye on a new COVID-19 variant called NB.1.8.1, or “Nimbus,” that has spread across Europe, the Americas and the Western Pacific. Nimbus is a descendant of the Omicron variant of the virus and was first identified in late January.