1. Krause PR, Fleming TR, Longini IM, Peto R, Briand S, Heymann DL, Beral V, Snape MD, Rees H, Ropero AM, Balicer RD, Cramer JP, Muñoz-Fontela C Gruber M, Sa Gaspar R, Singh JA, Subbarao K, Van Kerkhove MD, Swaminathan S, Ryan MJ, Henao‐Restrepo A. SARS-CoV-2 variants and vaccines. New England J Med 2021. DOI: 10.1056/NEJMsr2105280. https://www.nejm.org/doi/full/10.1056/NEJMsr2105280.
2. World Health Organisation. Tracking SARS-CoV-2 variants. Published online February 3, 2022. https://www.who.int/en/activities/tracking-SARS-CoV-2-variants/.
3. WHO Technical Advisory Group on COVID-19 Vaccine Composition. Interim Statement on COVID-19 vaccines in the context of the circulation of the Omicron SARS-CoV-2 Variant from the WHO Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC). Published online January 11, 2022. https://www.who.int/news/item/11-01-2022-interim-statement-on-covid-19-vaccines-in-the-context-of-the-circulation-of-the-omicron-sars-cov-2-variant-from-the-who-technical-advisory-group-on-covid-19-vaccine-composition.
4. Pfizer. Pfizer and BioNTech Initiate Study to Evaluate Omicron-Based COVID-19 Vaccine in Adults 18 to 55 Years of Age. Published online January 25, 2022. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-initiate-study-evaluate-omicron-based.
5. WHO. COVID-19 vaccine tracker and landscape. Published online January 25, 2022. https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines.