Unlike commonly available coronavirus tests that use polymerase chain reaction, or PCR, antigen diagnostics work by quickly detecting fragments of virus in a sample. The newly approved Quidel test will rely on specimens collected from nasal swabs, according to the F.D.A., and they can only be processed by the company’s lab instruments.
“Diagnostic testing is one of the pillars of our nation’s response to Covid-19, and the F.D.A. continues to take actions to help make these critical products available,” the agency said in a statement on Saturday. “One of the main advantages of an antigen test is the speed of the test, which can provide results in minutes.” The F.D.A. said it expects to grant emergency clearance for other antigen tests in the near future.
A shortage of coronavirus tests in the United States has hampered efforts to contain the pandemic, and has limited the capabilities of states seeking to