WHO declares a global public-health emergency.

Source:

• 
  December 24, 2020. Susie Neilson and Aylin Woodward. “A Comprehensive Timeline of the Coronavirus Pandemic at 1 Year, from China’s First Case to the Present.” Business Insider.
  https://www.businessinsider.com/coronavirus-pandemic-timeline-history-major-events-2020-3.
  Magazine.
• 
  May 12, 2020. Susan V. Lawrence. “COVID-19 and China: A Chronology of Events (December 2019-January 2020).” R46354. Congressional Research Service.
  https://crsreports.congress.gov/product/pdf/R/R46354/1.
  Government.