Agreed! Most asymptomatic when tested will go on to develop mild symptoms and some will die according to the same probabilities that effect everyone else without antibodies. It's a myth that there are large numbers of infected with no symptoms even after the incubation period, but the symptoms can be very mild. The test we have been using tests for active viral infection it will not reliably find those who were infected and now have antibodies. If we test for antibodies in those with no symptoms we will be finding those that had the virus, most likely had mild symptoms even if they say they had none, and now have resistance due to antibodies. The ones that say they had no symptoms are not lying, but who remembers the sniffles for a few days and a brief scratchy throat, or a low grade fever a month ago, that at the time they mistook for allergy or a simple cold.? The antibodies in most infected people, i would guess, will develop in response to the protein (antigen) tipped spikes on the intact virus particles. These "spikes" must be what binds to a receptor on target cells. I heard some guy say that chloroquine, the much mentioned malaria drug, may bind to the same receptor site that CoVid-19 binds. Maybe? Who knows? but if that's its mechanism as a CoVid drug, than its only going to be effective in the early stages of infection because that binding would be competitve with CoVid-19. I wouldn't think it would be very helpful in the U.S. where, by and large, we only test sick people, if that, and of course presidents and their son-in-laws. Chloroquin is being tested in a double blind study at the Univ. of Minnesota I believe. So it could be useful, perhaps , but more likely in Germany, where the test people without symptoms, than in the U.S.
By the way Chloroquine is structurally related to Quinine. I think I'll up my intake of Gin and Tonics.