1. World Health Organization. March 11, 2020. Accessed on June 28, 2021. URL: https://www.who.int/director-general/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-1911-march-2020
2. Ou, M. , Zhu, J. , Ji, P. , Li, H. , Zhong, Z. , Li, B. , Pang, J. , Zhang, J. and Zheng, X. , 2020. Risk factors of severe cases with COVID-19: a meta-analysis. Epidemiology & Infection, 148. URL: https://www.cambridge.org/core/product/identifier/S095026882000179X/type/journal_article.
3. Centers for Disease Control and Prevention. June 25, 2021. Covid Data Tracker Weekly Review. Accessed on June 28, 2021. URL: https://www.cdc.gov/coronavirus/2019-ncov/covid-data/covidview/index.html
4. The New York Times. June 24, 2021. Coronavirus World Map: Tracking the Global Outbreak. Accessed on June 28, 2021. URL: https://www.nytimes.com/interactive/2021/world/covid-cases.html
5. Food and Drug Administration. November 11, 2020. Accessed on June 28, 2021. URL: https://www.fda.gov/emergency-preparedness-and-response/mcm-legal-regulatory-and-policy-framework/emergency-use-authorization#coviddrugs