1. Davis A. COVID Evaluation Model Estimates 57 Percent of World Population Infected at Least Once. Newsweek April 28, 2022. https://www.newsweek.com/covid-evaluation-model-estimates-57-percent-world-population-infected-least-once-1672440. Accessed April 28, 2022
2. Devlin H. Seven in 10 people in England have had Covid, research shows. The Guardian April 22, 2022. https://www.theguardian.com/world/2022/apr/22/seven-in-10-people-in-england-have-had-covid-research-shows-omicron. Accessed April 28, 2022
3. COVID-19 Coronavirus pandemic. https://www.worldometers.info/coronavirus/. Accessed April 28, 2022
4. Thye AY, Law JW, Pusparajah P, et al (2021) Emerging SARS-CoV-2 Variants of Concern (VOCs): An Impending Global Crisis. Biomedicines 9(10):1303. https://doi.org/10.3390/biomedicines9101303
5. Coronavirus (COVID-19) Vaccinations. https://ourworldindata.org/covid-vaccinations?country=OWID_WRL. Accessed April 28, 2022