Outbreak of COVID-19 in Wuhan, China; Beginning of a Global Pandemic

In late December 2019, multiple cases of 'pneumonia of unknown cause' were reported in Wuhan, China. This was later identified as COVID-19, caused by the SARS-CoV-2 virus. On December 31, the WHO was notified of the outbreak. The virus spread rapidly across borders, leading to the most severe global public health crisis in a century, fundamentally changing global travel, economic structures, and social interactions for years.