In 2020, life changed across the globe.

Though initially discovered in Wuhan, China, in late 2019, COVID-19 entered the conversation in the U.S. in January 2020, when the Centers for Disease Control and Prevention (CDC) alerted the nation of the outbreak abroad. Later that month, the first national case of COVID-19 was reported in the state of Washington; by January 24, the virus had made its way to Chicago.

The outbreak escalated quickly from there, during a period of uncertainty about how the virus was transmitted, how quickly it could spread and how much of a threat it was to public health.

By March 2020, the World Health Organization (WHO) had declared COVID-19 a global health emergency and named the virus "severe acute respiratory syndrome coronavirus 2" or "SARS-CoV-2." It was also in March that WHO officially declared the COVID-19 outbreak a pandemic.

On January 30, 2023, the Biden Administration announced it will end the COVID-19 public health emergency declarations on May 11, 2023.

Three years after the WHO pandemic declaration, Northwestern Medicine looks back at the milestones we’ve passed and the medical advances we’ve achieved that continue to save lives.