Wired NB.1.8.1 has mutations that could increase the virus’s transmissibility and decrease the efficacy of certain neutralizing antibodies against it. A new Covid variant is being kept under surveillance by the World Health Organization (WHO) as its emergence has led to an increase in infections in several regions of the world. First identified at the end of January, the variant—called NB.1.8.1 but known informally as “Nimbus”—is a descendant of the Omicron family of Covid sublineages, and has become increasingly prevalent throughout the spring in Europe, the Americas, and the Western Pacific.
WHO Monitors New Covid Variant Spreading in America and Europe
- Published Jun 10, 2025