There is an urgent need for an accurate antibody test SERO for severe acute respiratory syndrome MESHD coronavirus 2 (SARS-CoV-2). In this paper, we have developed 3 ELISA SERO methods, trimer spike IgA, trimer spike IgG, and nucleocapsid IgG, for detecting anti- SARS-CoV-2 antibodies SERO. We evaluated their performance SERO in comparison with four commercial ELISAs SERO, EDI Novel Coronavirus COVID-19 ELISA IgG SERO and IgM, Euroimmun Anti-SARS-CoV-2 ELISA IgG SERO and IgA, and one lateral flow assay, DPP COVID-19 IgM/IgG System (Chembio). Both sensitivity SERO and specificity were evaluated and the causes of false-positive reactions were determined. The assays were compared using 300 pre-epidemic samples and 100 PCR-confirmed COVID-19 samples. The sensitivities SERO and specificities of the assays were as follows: 90%/100% (in-house trimer spike IgA), 90%/99.3% (in-house trimer spike IgG), 89%/98.3% (in-house nucleocapsid IgG), 73.7%/100% (EDI nucleocapsid IgM), 84.5%/95.1% (EDI nucleocapsid IgG), 95%/93.7% (Euroimmun S1 IgA), 82.8%/99.7% (Euroimmun S1 IgG), 82.0%/91.7% (Chembio nucleocapsid IgM), 92%/93.3% (Chembio nucleocapsid IgG). The presumed causes of positive signals from pre-epidemic samples in commercial and in-house assays were mixed. In some cases, positivity varied with assay repetition. In other cases, reactivity was abrogated by competitive inhibition (spiking the sample with analyte prior to performing the assay). In other cases, reactivity was consistently detected but not abrogated by analyte spiking. Overall, there was wide variability in assay performance SERO using our samples, with in-house tests exhibiting the highest combined sensitivity SERO and specificity. The causes of false positivity in pre-epidemic samples may be due to plasma SERO antibodies SERO apparently reacting with the analyte, or spurious reactivity may be directed against non-specific components in the assay system. Identification of these targets will be essential to improving assay performance SERO.