FILE - This Aug. 2, 2018, file photo shows the U.S. Food and Drug Administration building behind FDA logos at a bus stop on the agency's campus in Silver Spring, Md. U.S. regulators have approved a new type of coronavirus test that administration officials have touted as a key to opening up the country. The Food and Drug Administration on Saturday, May 9, 2020, announced emergency authorization for antigen tests developed by Quidel Corp. of San Diego. The test can rapidly detect fragments of virus proteins in samples collected from swabs inside the nasal cavity, the FDA said in a statement. (AP Photo/Jacquelyn Martin, File)