IgM and IgG antibodies represent different stages of an immune response against COVID-19

The presence of #IgM and #IgG antibodies represent different stages of a body's immune response against the #coronavirus.

An IgM antibody test has an important role to play because IgM #antibodies typically appear earlier during infection. So an IgM assay can act as a confirmatory test for a PCR test. For example, if a clinician gives a PCR test to someone and it comes back negative, but they have a feeling that the patient truly has an infection, IgM would be a great test to use on that patient to get
a second confirmation.

Combined assays that detect both IgM and IgG antibodies are problematic because clinicians won't know what part of the immune response they are actually measuring. They are simply getting a single number, and don't know if that number is caused by IgM, that early immune response that is fleeting, or by IgG, which is indicative of a longer-lasting immune response.

This confusion will lead to the need for additional testing. So for example, if a total antibody test is positive, a clinician would have to follow up with an IgM test, Novus IgM, or perhaps a PCR test to measure active infection or an IgG test to know if that patient has reached a longer-lasting immune response.

The advantage of a standalone IgG test is that it is a much more specific test. Clinicians know they are measuring IgG antibodies, which are more indicative of that longer-term immune response that they are looking for.

For more information, please visit www.BeckmanCoulter.com/Coronavirus