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. The virus has mutations that may increase its infectiousness and allow it to escape certain antibodies. Like other variants before it, Nimbus has specific mutations to its spike protein. However, the WHO says that there is no evidence that this variant causes more severe disease compared to other strains currently circulating. The WHO experts explain that, although this variant may partially evade some antibody responses, such “immune escape” is comparable to that observed in other Omicron sublineages.