COVID-19 SARS-CoV-2 Testing

IgM and IgG antibodies to SARS-CoV-2 are generally detectable in blood several days after initial infection. IgM presence is often associated with late acute phase of infection, which means the IgM test can alert the physician that there is likely an acute infection, suggesting that clinical action should be taken (treatment, patient isolation/quarantine, or return visit). In contrast, IgG presence suggests a recent or prior infection. Therefore, the combination of SARS-COV-2 IgM and IgG tests is intended for identifying individuals with an adaptive immune response to SARS-CoV-2, and could provide relevant information to help better understand the stage of infection.