The Search for Antibodies

Late is better than never right? We needed tests for the nasty virus spreading across the world and it seems like we are finally beginning to pump them out. But what do these tests look for? And what exactly can these results tell us? As of now, antibodies of IgM and IgG can tell us a lot about what is going on in your body in relation to COVID-19. Follow me, your non-qualified specialist in the antibody response for COVID-19.

The FDA does a good job explaining the results of a current test, the qSARS-CoV-2 IgG/IgM Rapid Test. Basically, this test can plasma, serum, or whole blood samples and analyzes the amount of IgG and IgM in these. If IgM antibodies are present, since these are the first responders to infection, one could determine that a patient has an active or very recent infection with COVID0-19. Let’s just say you don’t want to see a positive sign for this. Since it takes longer for IgG antibodies to be present, about 7-10 days, this could signal to the professional that the patient had a past infection. With all this information however, the FDA wants to make CLEAR that these tests do NOT rule out the fact of COVID-19 infection if shown up negative. In fact, they don’t know the absolute sensitivity of the test itself. AHHH!!

This is just one test however. There continue to be studies, attempting to hone in on what exactly the immune response would look like in order for someone to be tested positive for this virus. A study looked at the relationship between COVID-19 immune response and related coronaviruses such as SARS and MERS. With limited patient studies out, they found that this virus mounted an immune response that was most similar to SARS than any other coronavirus. In one patient they found that it took approximately 9 days to show a peak in the IgM antibody and switched to IgG when it reached 2 weeks. Deciding just what titers are specific to the disease severity could prove to be very important in creating a vaccine. We are in this together. Cooperativity from all nations and scientists could speed this up. Stay strong everyone, we can do this!