A relatively new and seemingly highly contagious variant of Covid, NB.1.8.1, or the “Nimbus” variant, has been described by the World Health Organisation (WHO) as a “variant under monitoring” (VUM). That’s partly because it seems to be so easily transmissible,

NB.1.8.1, a new COVID-19 variant that has caused concern among WHO officials, is now spreading in America, according to CDC data.