Last week the FDA issued emergency use authorization for a new type of test that can detect SARS CoV2 called an antigen test. The EUA was issued to Quidel Corporation for its Sofia 2 SARS Antigen FIA. The test is authorized for use in high and moderate complexity laboratories and facilities certified by CLIA.
The test looks for protein fragments associated with the virus. The sample is collected with a nasal swab. It can produce a result in minutes. The antigen test is cheaper and easier but is less reliable than the nasal swab PRC test.
The new antigen test is very specific for the virus but is less sensitive than the molecular PCR tests. In other words, there are very few false positives but there will be false negatives, meaning that negative results do not rule out infection.
