The immune system produces antibodies in response to illness or vaccination. The virus responsible for SARS-CoV-2, also known as COVID-19, causes respiratory illness in humans. Antibody testing for SARS-CoV-2 identify individuals who have developed immunity to the virus. Antibody tests for SARS-CoV-2 can assist determine whether or not a person has been exposed to the SARS-CoV-2 virus or is a COVID-19 survivor. Active COVID-19 infection cannot be determined by an antibody test.