On December 31, 2019, China announced the discovery of a cluster of pneumonia cases in Wuhan. The first American case of COVID-19 was reported on January 20, and Health and Human Services Secretary Alex Azar declared a public health emergency on January 31. Restrictions were placed on flights arriving from China, but the initial U.S. response to the COVID-19 pandemic was otherwise slow in terms of preparing the healthcare system, stopping other travel, and testing. The first known American deaths occurred in February and in late February President Donald Trump proposed allocating $2.5 billion to fight the outbreak. Instead, Congress approved $8.3 billion and Trump signed the Coronavirus Preparedness and Response Supplemental Appropriations Act, 2020 on March 6. Trump declared a national emergency on March 13. The government also purchased large quantities of medical equipment, invoking the Defense Production Act of 1950 to assist. By mid-April, disaster declarations were made by all states and territories as they all had increasing cases. A second wave of infections began in June, following relaxed restrictions in several states, leading to daily cases surpassing 60,000. By mid-October, a third surge of cases began; there were over 200,000 new daily cases during parts of December 2020 and January 2021.
COVID-19 vaccines became available in December 2020, under emergency use, beginning the national vaccination program, with the first vaccine officially approved by the Food and Drug Administration (FDA) on August 23, 2021. Studies have shown them to be highly protective against severe illness, hospitalization, and death. In comparison with fully vaccinated people, the CDC found that those who were unvaccinated were from 5 to nearly 30 times more likely to become either infected or hospitalized. There nonetheless was some vaccine hesitancy for various reasons, although side effects were rare. There were also numerous reports that unvaccinated COVID-19 patients strained the capacity of hospitals throughout the country, forcing many to turn away patients with life-threatening diseases.