Nimbus, or NB.1.8.1, is a new variant of SARS-CoV-2, the virus responsible for COVID-19. Like its predecessors, it carries a unique set of mutations that differentiate it from previous strains.

A new COVID-19 strain, referred to as NB.1.8.1 or "Nimbus," first appeared in the U.S. sometime near the end of April and is currently the dominant variant in the U.S. The new variant is said to ...