And also notice what happens in this phase. In this case, we have a very sharp decline in the concentration and it drops to very low undetectable level. But in this particular case, it doesn't drop to low value, it remains relatively high. And that essentially ensures that all that pathogenic antigen is completely destroyed by the antibodies in our blood. Now, in the case of the primary response, the major immunoglobulin was immunoglobulin M. But in the case of our secondary response, the major immunoglobulin is immunoglobulin G. So once again, following the first infection, the immune system will produce memory cells that will carry that copy of the antibody that is specific to that particular antigen. And when the antigen reinfects our body the second time we're already going to have that antigen, that antibody circulating inside our blood.