1. WHO Timeline COVID-19, Who,2020
2. Pandemics: risks, impacts, and mitigation;Madhav,2017
3. Can COVID vaccines stop transmission? Scientists race to find answers;Mallapaty;Nature,2021
4. Challenges in ensuring global access to COVID-19 vaccines: production, affordability, allocation, and deployment;Wouters;Lancet,2021
5. Etiologies of sarcoidosis;Chen;Clin. Rev. Allergy Immunol.,2015