Timeline of the COVID-19 Pandemic
This page lists the chronology and epidemiology of SARS-CoV-2, the virus that causes the coronavirus disease 2019 (COVID-19) and is responsible for the COVID-19 pandemic. The first human cases of COVID-19 were identified in Wuhan, China, in December 2019. The World Health Organization declared the COVID-19 outbreak a Public Health Emergency of International Concern on 30 January 2020, and a pandemic on 11 March 2020. At this stage in the pandemic (June 2021), it is not possible to conclusively determine precisely how humans in China were initially infected with SARS-CoV-2. Furthermore, some developments may become known or fully understood only in retrospect.