1. COVID-19 Map - Johns Hopkins Coronavirus Resource Center,2020
2. Azar AM. Emergency Use Authorization Declaration. Published online 2020. https://www.federalregister.gov/documents/2020/04/01/2020-06905/emergency-use-authorization-declaration
3. FDA Issues Emergency Use Authorization for Third COVID-19 Vaccine,2021
4. Developing Covid-19 Vaccines at Pandemic Speed;Lurie;N Engl J Med,2020
5. BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting;Dagan;N Engl J Med.,2021