People tour the National Mall in Washington, D.C., the United States, July 19, 2020. Long delays in getting COVID-19 test results across the United States is undercutting their usefulness, said Director of the U.S. National Institutes for Health Francis Collins on Sunday.

People wearing face masks tour the National Mall in Washington, D.C., the United States, July 19, 2020. Long delays in getting COVID-19 test results across the United States is undercutting their usefulness, said Director of the U.S. National Institutes for Health Francis Collins on Sunday.

People tour the National Mall in Washington, D.C., the United States, July 19, 2020. Long delays in getting COVID-19 test results across the United States is undercutting their usefulness, said Director of the U.S. National Institutes for Health Francis Collins on Sunday.

Nearly empty streets are seen near the Capitol Hill in Washington, D.C., the United States, July 19, 2020. Long delays in getting COVID-19 test results across the United States is undercutting their usefulness, said Director of the U.S. National Institutes for Health Francis Collins on Sunday.

A group of cyclists take a break on the sidewalk on the National Mall in Washington, D.C., the United States, July 19, 2020. Long delays in getting COVID-19 test results across the United States is undercutting their usefulness, said Director of the U.S. National Institutes for Health Francis Collins on Sunday.

People tour the National Mall in Washington, D.C., the United States, July 19, 2020. Long delays in getting COVID-19 test results across the United States is undercutting their usefulness, said Director of the U.S. National Institutes for Health Francis Collins on Sunday.

People take electric scooters on the National Mall in Washington, D.C., the United States, July 19, 2020. Long delays in getting COVID-19 test results across the United States is undercutting their usefulness, said Director of the U.S. National Institutes for Health Francis Collins on Sunday. (Photos: Ting Shen/Xinhua)