Table 1 The main epidemic prevention and control policies in the United States^a

1. Border prevention and control measures

(1) On February 2, 2020, non-US citizens from or recently in China were prohibited from entering.

(2) On March 21, 2020, the federal government closed the US borders with Canada and Mexico.

(3) On September 14, 2020, the government canceled the requirements for directing all flights carrying airline passengers arriving from, or recently had a presence in, certain countries to land at one of 15 designated airports and stopped strengthening entry health screening for these passengers. It also strengthened entry health screening for people arriving from, or with recent presence in, China (excluding Hong Kong and Macau), Iran, the Schengen region of Europe, the United Kingdom (excluding overseas territories outside of Europe), Ireland, and Brazil.

(4) On December 28, 2020, the CDC asked air travelers from the United Kingdom to the United States to provide a negative test for the virus within 72 hours before boarding.

(5) On January 26, 2021, the CDC required all air passengers entering the United States from foreign countries to be tested within 3 days before flight departure and to present an order certifying a negative test before boarding.

2. Measures for anti-epidemic materials

(1) On March 28, 2020, the first temporary hospital in New York was completed.

(2) On August 23, 2020, the FDA approved the use of recovered plasma to treat patients with severe COVID-19.

(3) On January 5, 2021, the FEMA revised the list of Personnel Protective Equipment and other scarce and critical health and medical resources that will be reviewed and may be reserved for domestic use before export, including surgical N95 respirators, nitrile gloves, exam gloves, etc.

3. Declaring a state of emergency across the country

(1) Starting from March 5, 2020, various states in the United States have entered a state of emergency.

(2) On March 13, 2020, US President Trump declared a national emergency.

(3) On April 1, 2020, US President Trump approved 30 states to enter the "disaster state" of the epidemic.

(4) On April 11, 2020, US President Trump approved Wyoming as a "major disaster state" for the COVID-19 epidemic. It was the first time in the history of the United States that all 50 states, Washington D.C, and the four overseas territories including the U.S. Virgin Islands, Northern Mariana Islands, Guam and Puerto Rico have all entered a "major disaster state."

4. Testing and contact tracing measures

(1) On February 29, 2020, the FDA announced an "emergency use authorization" to expand testing capabilities.

(2) On March 13, 2020, the FDA urgently approved a kit produced by the Swiss pharmaceutical company Roche, which can obtain test results within 3.5 hours and test 4128 samples within 24 hours. (0.12 total tests per thousand people)

(3) On March 13, 2020, Trump stated that "drive-through" new coronavirus testing stations would be promoted nationwide in the coming weeks to improve testing capabilities.

(4) Since early April 2020, teams appointed by state governors have worked with experts to develop state testing plans that include contact tracing testing and surveillance of asymptomatic individuals. (more than 5.07 total tests per thousand people)

(4) On November 4, 2020, Dr. Robert Redfield, director of CDC, proposed the need for a new COVID-19 testing strategy to improve the ability to identify asymptomatic COVID-19 infections. (481.87 total tests per thousand people)

(5) On February 17, 2021, the Biden government announced that it would take action to expand COVID-19 detection capabilities. The CDC would invest nearly $200 million to identify, track, and mitigate the emerging SARS-CoV-2 strains through genome sequencing. The HHS, in partnership with the DOD, would make a $650 million investment to expand testing opportunities for K-8 schools and underserved congregate settings, such as homeless shelters. (1000.21 total tests per thousand people)

(6) Two new over-the-counter at-home COVID-19 tests were introduced to the US market in late December 2021. (more than 2095 total tests per thousand people)

5. Campus prevention and Control measures

(1) Starting from March 8, 2020, major colleges and universities across the United States suspended classes one after another.

(2) Starting from March 12, 2020, primary and secondary schools in the United States from kindergarten to grade 12 of high school began to suspend classes for a period of time ranging from 2 to 6 weeks.

(3) On July 6, 2020, the US Immigration and Customs Enforcement (ICE) announced that international students would be required to leave the country if all US schools began long-distance e-learning in the fall of 2020. At the same time, if the school only offered online courses, the immigration office would not issue visas to international students who were still abroad.

(4) On July 12, 2020, the ICE said that the visas of American university students who were stranded outside the United States due to the outbreak and could only take online classes were still valid.

(5) On July 14, 2020, the Trump administration officially lifted the rule that international students could not enter or stay in the United States with only online classes.

(6) Schools in many states gradually reopened in early August 2020.

6. Maintaining social distancing and community control measures

(1) On March 14, 2020, the CDC had a No Sail Order in place, and the three major cruise companies, Carnival Group, Royal Caribbean, and Norwegian Cruise Line, have completely suspended cruise operations.

(2) On March 16, 2020, the United States government considered taking measures such as quarantine and curfew in "hot spots", but not nationwide.

(3) In late March 2020, people in the areas with more severe epidemics were required to stay at home. On March 30, Washington issued a stay-at-home order.

(4) On May 13, 2020, Washington D.C Mayor Moore Bowser announced that the local state of emergency, public health emergency and "home order" would be extended to June 8.

(5) On June 22, 2020, CDC released "Considerations for Election Polling Locations and Voters" making specific recommendations for reducing infectious behaviors, maintaining a healthy environment, and maintaining healthy practices.

(6) On November 15, 2020, the Governor of Washington announced statewide restrictions, including prohibiting indoor social gatherings with people outside the family, closing restaurants and bars that provide indoor services, allowing take-out services, restricting outdoor dining, restricting the number of people in the religious service room, closing fitness facilities and gyms, etc.

(7) On December 3, 2020, California, one of the "severely hit areas" of the epidemic, issued a stay-at-home order.

(8) On February 2, 2021, the CDC required individuals to wear masks in all transportation networks in the United States, including airports, commercial aircraft, road buses, commuter buses, and rail systems, and then this requirement was extended to September 13.

7. Economic relief measures

(1) On March 18, 2020, the "Families First Coronavirus Response Act" was approved to provide two weeks of paid sick leave and family leave and increase government funding for health care, food benefits, and unemployment benefits.

(2) On March 27, 2020, the "Coronavirus Aid, Relief, and Economic Security Act" was passed, providing $2.2 trillion in funding for individuals, small businesses, large corporations, state and local governments, and other public health initiatives, and it was also a major source of funding for medical interventions like vaccines and rapid testing.

(3) In March 2021, more than $170 billion in new resources was allocated to the US Department of Education through the "American Relief Plan Act" to support ongoing states and agencies recovery efforts.

8. Vaccination measures

(1) On December 8, 2020, the government issued an executive order on securing access to the US government's COVID-19 vaccine.

(2) On January 26, 2021, the government increased the weekly vaccine supply to states and territories from 8.6 million doses to at least 10 million doses, and planned to purchase an additional 200 million doses of vaccine to vaccinate people.

(3) On May 10, 2021, the FDA extended the emergency use authorization of the Pfizer-BioNTech COVID-19 vaccine to teenagers between 12 and 15 years old.

9. Lifting restrictions

(1) From April 20, 2020, South Carolina and other states or regions gradually reopened businesses and restaurants. By the end of May, most states or regions opened businesses and restaurants.

(2) In May, the United States began to see a concentrated "resumption of work and production", and many states introduced plans to restart the economy one after another.

(3) The CDC announced that the "Navigation ban" would be lifted from November 2020 and replaced by the "Conditional Sailing Order".

(4) On May 13, 2021, the CDC announced that in most cases, fully vaccinated Americans no longer need to wear masks indoors and maintain social distance.

(5) On May 15, 2021, the CDC stated that many K-12 schools that had strictly implemented prevention strategies had been able to safely open for face-to-face instruction and remain open, and it recommended that schools implemented phased prevention strategies.