On Dec. 31, 2019, Chinese authorities alerted the World Health Organization of pneumonia cases in Wuhan City, Hubei province, China, with an unknown cause. What started as a mystery disease was first referred to as 2019-nCoV and then named COVID-19.
The timeline below tracks the development of the outbreak in 2020. For newer developments, visit Devex’s COVID-19 timelines for 2021 and 2022.
Dec. 31 — WHO issues emergency use validation for the Pfizer-BioNTech COVID-19 vaccine, the first COVID-19 vaccine to receive one. This would help countries expedite regulatory approval of the vaccine. WHO’s Strategic Advisory Group of Experts on Immunization or SAGE will convene on Jan. 5 to discuss specific recommendations on its usage.