The argument put forth is that it conclusively proves that antibodies to COVID-19 don't last very long. But if I read the study, what it actually says is only 4% of healthcare workers had IgG antibodies. It further says that 89% of the 1400-odd verified COVID-19 patients they tested had antibodies while 4% of the 2800-odd unknown-covid-status healthcare workers did.
What this seems to say to me is "most healthcare workers in the study didn't catch COVID."
Am I reading this wrong?