1. Centers for Disease Control and Prevention. Science brief: omicron (B.1.1.529) variant. Dec 2021. https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/scientific-brief-omicron-variant.html.
2. World Health Organization. Classification of omicron (B.1.1.529): SARS-CoV-2 variant of concern. Nov 2021. https://www.who.int/news/item/26-11-2021-classification-of-omicron-(b.1.1.529)-sars-cov-2-variant-of-concern.
3. SPI-M-O. Consensus statement on covid-19. 7 Dec 2021. https://www.gov.uk/government/publications/spi-m-o-consensus-statement-on-covid-19-7-december-2021/spi-m-o-consensus-statement-on-covid-19-7-december-2021#omicron-variant.
4. Sky News. Twitter. Dec 2021. https://twitter.com/SkyNews/status/1468842411291992067.
5. World Health Organization Office for Africa. Omicron spreads but severe cases remain low in South Africa. Dec 2021. https://www.afro.who.int/news/omicron-spreads-severe-cases-remain-low-south-africa