April. 29, 2020, Preprint Paper "Towards the next phase: evaluation of serological assays for diagnostics and exposure assessment", corresponding author Erasmus Medical Centre, Rotterdam, the Netherlands, shows that the assay detecting total immunoglobulins against the receptor binding domain of SARS CoV- 2, had optimal characteristics for antibody detection in different stages of disease.

Evaluation Results show that, Wantai total Ig detection ELISA kit has optimal performance with sensitivity 98.68% (75/76), and specificity 99.33% (148/150). Wantai SARS-CoV-2 Total Ab ELISA is a two step incubation antigen "sandwich" enzyme immunoassay kit.

Reference: Towards the next phase: evaluation of serological assays for diagnostics and exposure assessment.
doi: https://doi.org/10.1101/2020.04.23.20077156