FDA issued an emergency use authorization for the first antibody point-of-care test for COVID-19. The “Assure COVID-19 IgG/IgM Rapid Test Device” was given emergency use authorization in July to help identify individuals with antibodies to SARS-CoV-2. The EUA was reissued this week authorizing the test using the fingerstick method. The press release is here.
Rapid antibody tests that also include a specific test for IgM antibodies can sometimes be useful to identify newly infected people. That’s because the very first antibodies that your immune system makes are IgM (these are your emergency response antibodies).
The presence of IgM indicates a very recent COVID infection- as opposed to the presence of IgG antibodies- which indicates a historic infection. Still- it’s better to rely on an antigen test than an IgM antibody test to identify newly infected people when you need a rapid test result.
