Overview

• NB.1.8.1, nicknamed Nimbus, now represents about 37% of U.S. COVID-19 cases and accounts for 55% of infections in California.
• Wastewater monitoring across Southern California reports moderate-to-high viral levels reflecting the variant’s rapid proliferation.
• The World Health Organization lists Nimbus as a variant under monitoring and assesses its global public health risk as low.
• There is no evidence that Nimbus leads to more severe illness or higher hospitalization rates compared with earlier variants.
• Medical authorities recommend staying current on COVID-19 vaccinations, wearing masks in high-risk settings and maintaining hand hygiene to limit transmission.