But the first antibody produced against the virus in the first two weeks is IgM antibody. That IgM stays in the body for about eight weeks. The peak is at four weeks, so do not do that test only two weeks after being infected because the antibodies just started to be produced. Maybe it’s not enough to be detected by the methods because the methods are not highly sensitive. Especially the kind of kits I’m talking about, these Yes or No like pregnancy test, but at four weeks, when it’s at high levels, will be the best time to test for IgM antibodies. If IgM antibody is positive, it is highly likely that the person was exposed to the virus and produced high levels of IgM antibodies and that’s indication of exposure in past, let’s say four maximum eight weeks.