This blood test, which is authorized by the FDA under an Emergency Use Authorization (EUA)*, is designed to detect antibodies to SARS-CoV-2, the virus that causes COVID-19 (this is not a test meant for detecting an active infection**). Antibodies are proteins that the body produces in response to infections. The antibodies can be produced even if a person has few or no symptoms during the infection.
About COVID-19 Antibodies
It generally takes 1-3 weeks (sometimes longer) after an infection for antibodies to SARS-CoV-2 to become detectable in the blood. There is not enough evidence to know whether having antibodies to SARS-CoV-2 will prevent reinfection or if the virus is no longer present. Antibodies are generally detectable in the blood for a period of time after a person has recovered from the infection. Whether you have been tested for infection or antibodies, recovered from an active infection, or have had no symptoms at all, COVID-19 is highly contagious and you should take preventive measures to protect yourself and others. We do not know yet if people who recover from COVID-19 can get infected again. Scientists are working to understand this.