Validation of Roche immunoassay for severe acute respiratory coronavirus 2 in South Africa

Background: Serology testing is an important ancillary diagnostic to the reverse transcriptase polymerase chain reaction (RT-PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We aimed evaluate performance of Roche Elecsys™ chemiluminescent immunoassay (Rotkreuz, Switzerland), that detects antibodies against SARS-CoV-2 nucleocapsid antigen, at academic laboratory in South Africa. Methods: Serum samples were collected from 312 donors with confirmed positive RT-PCR tests, approval a large university’s human research ethics committee. Negative controls included stored prior December 2019 and patients who tested negative on using multiple serology methods ( n = 124). Samples –80 °C analysed cobas™ 602 autoanalyser. Results: Compared RT-PCR, our evaluation revealed specificity 100% overall sensitivity 65.1%. The individuals > 14 days’ post-diagnosis was 72.6%, highest 31–50 88.6%. Results also compared in-house tests showed high agreement majority categories. Conclusions: all-time points lower than reported other studies, but appropriate cohorts approached 90% specificity. earlier time or without symptomatology may indicate failure produce antibodies, which further supported by comparison tests.