Andrew Huberman· PhD
If you hear IgM, the IgM is the first of the adaptive immune responses, and it tends to come on earlier. So if somebody is immunopositive for IgM for a particular type of viral or bacterial invader, that means that it was a fairly recent infection. Later, one creates... The adaptive immune system, I should say, creates an IgG, which is the more stable form of the specific antibody that's going to recognize a given invader. So IgG tends to come up a little bit later.