On 24 November 2021, South Africa notified the World Health Organization (WHO) of the presence of a new SARS-CoV-2 lineage: B.1.1.529. After a rapid assessment of the situation, the WHO designated it as a new variant of concern (VOC): Omicron. This scientific briefing by the Microbiology Department at the Laboratoire national de santé aims to address the different concerns regarding this new variant.