November 24, 2021,
A new variant of SARS-CoV-2, B.1.1.529, has been reported to the World Health Organization (WHO). This new strain was first detected in samples collected on November 11, 2021 in Botswana and November 14, 2021 in South Africa.
On November 26, 2021, WHO designated B.1.1.529 Omicron and classified it as a Variant of Concern (VOC).
On November 30, 2021, the United States designated Omicron as a Variant of Concern, and on December 1, 2021, the first confirmed case of Omicron in the United States was identified.