About Quizzes


COVID-19 is one of the worst pandemics in recent history in terms of number of infections, death count, and economic impact. Several waves of COVID infections occurred in the U.S. beginning in March 2020, with the largest in winter 2020-21, late summer 2021, and winter 2022. Vaccines became available in early 2021, but vaccine hesitancy, waning immunity, and emergence of highly infectious variants of COVID-19 prevented eradication of the virus.

To date, COVID-19 has infected more than 80 million and resulted in the death of 1 million Americans. On the world-wide scale, COVID-19 has infected 520 million people, resulting in the death of more than 6 million.

Early Days & Detection of Virus

At this time, it is unclear exactly when and where the first cases of COVID-19 occurred. It is known that the virus originated in China, and the first outbreak seemed to have occurred at the Huanan Seafood Wholesale Market in Wuhan, Hubei Province sometime in early December 2019. By the end of December, the World Health Organization was informed of a cluster of cases of pneumonia in Wuhan with an unknown cause.

In early January, Chinese public health authorities identified the unknown pneumonia as a novel coronavirus. On January 23, the entire population of Wuhan was put in quarantine. The virus was eventually called COVID-19 by the World Health Organization, with the name an abbreviated version of coronavirus disease 2019.

In the U.S., the first laboratory-confirmed case of COVID-19 occurred in Washington state from a sample taken on January 18 from a person who had recently returned from Wuhan. Later, retroactive testing revealed that the earliest American deaths due to COVID-19 occurred in early January, so it is possible that spread of the virus in the U.S. had been occurring as far back as November.

On March 11, the World Health Organization declared COVID-19 a pandemic. A few days later, on March 13, president Donald Trump declared a nationwide emergency in the U.S.

National Infection Trends

By mid-April 2020, most U.S. states reported widespread cases of COVID-19, but stay-at-home orders had kept numbers relatively low until the summer of 2020, when the economy started to open up again and social distancing measures were reduced. Some states, especially those in the South, had a spike in COVID cases, resulting in postponement or reversal of openings. In mid-July 2020 the U.S. recorded a record 75,600 cases of COVID-19 in a single day. For the first time, the U.S. exceeded 200,000 cases in one day at the end of November, then saw another high in early January with nearly 300,000 cases per day. Cases dropped dramatically after winter 2021, but surpassed 300,000 per day again in September 2021 with the rise of the Delta variant. In November, the highly-contagious, vaccine-resistant omicron variant was detected in Africa, and by early January cases in the U.S. exceeded 1 million per day.

U.S. COVID-19 Death Toll Timeline

April 2020: 23,000 deaths

May 2020: 100,000 deaths

September 2020: 200,000 deaths

December 2020: 300,000 deaths

January 2021: 400,000 deaths

February 2021: 500,000 deaths

June 2021: 600,000 deaths

October 2021: 700,000 deaths. Exceeds estimated U.S. deaths from 1918 Spanish flu.

December 2021: 800,000 deaths

February 2022: 900,000 deaths May 2022: 1,000,000 deaths

Sources & Further Reading

AJMC Staff. 2021. A Timeline of COVID-19 Developments in 2020. The American Journal of Managed Care: Cranbury, New Jersey. Accessed Nov 13, 2021. www.ajmc.com/view/a-timeline-of-covid19-developments-in-2020

Centers for Disease Control and Prevention. 2021. CDC Museum COVID-19 Timeline. David J. Sencer CDC Museum: Atlanta, Georgia. Accessed Nov 11, 2021. www.cdc.gov/museum/timeline/covid19.html