Nimbus COVID Variant Becomes Dominant US Strain With New Razor Blade Throat Symptom

The Omicron subvariant NB.1.8.1, nicknamed Nimbus, has become the dominant COVID-19 strain in the United States, accounting for 43% of cases as of late June 2025, according to CDC data. Nimbus is notable for causing a particularly severe sore throat symptom described as a “razor blade throat,” characterized by intense pain resembling shards of glass, which differs from earlier predominant symptoms like loss of taste or smell. While the World Health Organization and UK Health Security Agency classify Nimbus as a variant under monitoring, current data do not indicate it causes more severe illness or increased hospitalizations compared to previous variants. The variant is spreading internationally, with detected cases in the UK and parts of Asia, but vaccination remains the primary recommended defense, especially for at-risk populations such as older adults and immunosuppressed individuals. Due to a decline in sequencing reports, the exact geographic spread within the U.S. is not fully clear, but Nimbus has been found in at least 18 states. Medical experts suggest systemic treatments like ibuprofen to manage the painful sore throat symptom, and they emphasize that symptoms may vary, so individuals experiencing any signs of COVID-19 should get tested promptly.