NB.1.8.1 (Nimbus) Becomes Dominant U.S. COVID Strain, Linked to Severe Throat Symptoms The emergence of the NB.1.8.1 (Nimbus) variant as a dominant SARS-CoV-2 strain in the U.S. highlights evolving viral transmission dynamics and immune escape capabilities. Its association with atypical... Right to health Signs Well-being Aug 6, 2025