The Food and Drug Administration granted the first emergency use license to the diagnostic healthcare company Quidel Corp. for the first COVID-19 antigen test, the agency said. Antigen tests can detect coronavirus quickly, but are generally considered to be less accurate than other types of tests for the virus.
Antigen tests for COVID-19 are similar to rapid tests for influenza or strep throat. This test can be done in a laboratory or doctor’s office and takes only about 15 minutes.
The tests commonly used to diagnose COVID-19, called PCR tests, are used to find the genetic sequence of the coronavirus in a swab taken from the nose or throat of a patient. Antigen tests, on the other hand, look for molecules on the surface of the virus. They return results much faster, but are less accurate. If the test indicates that a patient sample is positive, it is likely to be correct. But Quidel’s test has a high rate of false negatives: it correctly identifies patient samples that contain the coronavirus 85% of the time, the company’s general manager told The Wall Street newspaper.
The FDA says negative results from an antigen test should be confirmed by a PCR test.
Quidel’s CEO told WSJ the company is ramping up manufacturing to increase production of the test, officially called Sofia 2 SARS Antigen FIA, with the goal of producing 1 million per week.