1. Centers for Disease Control Control and Prevention (2023, March 25). SARS-CoV-2 Variant Classifications and Definitions, Available online: https://www.cdc.gov/coronavirus/2019-ncov/variants/variant-classifications.html.
2. WHO (2023, June 14). Updated Working Definitions and Primary Actions for SARS-CoV-2 Variants. Available online: https://www.who.int/publications/m/item/updated-working-definitions-and-primary-actions-for--sars-cov-2-variants.
3. World Health Organization (2023, June 14). Statement on the Update of WHO’s Working Definitions and Tracking System for SARS-CoV-2 Variants of Concern and Variants of Interest. Available online: https://www.who.int/news/item/16-03-2023-statement-on-the-update-of-who-s-working-definitions-and-tracking-system-for-sars-cov-2-variants-of-concern-and-variants-of-interest.
4. Mathieu, E., Ritchie, H., Rodés-Guirao, L., Appel, C., Gavrilov, D., Giattino, C., Hasell, J., Macdonald, B., Dattani, S., and Beltekian, D. (2023, June 16). Coronavirus Pandemic (COVID-19). Available online: https://ourworldindata.org/covid-cases/.
5. Characterizing long COVID in an international cohort: 7 months of symptoms and their impact;Davis;Eclinicalmedicine,2021