The detection sensitivity of models iACE2/RBD-Fc, iACE2/S1-Fc and iS1/ACE2-His in detecting SARS-CoV-2 nAbs was further evaluated using 12 COVID-19 convalescent plasma samples and 18 SARS-CoV-2 inactivated vaccine serum samples. The gene discussed is ACE2; the disease is COVID-19.