Comprehensive, comparative evaluation of 25 automated SARS-CoV-2 serology assays

The onset of the COVID-19 pandemic resulted in hundreds of in vitro devices coming to market, facilitated by regulatory authorities allowing "Emergency Use," without a prior comprehensive evaluation of performance. The World Health Organization released Target Product Profiles specifying acceptable performance characteristics for SARS-CoV-2 devices. We evaluated 16 automated serology test kits that detect IgG or Total antibodies to SARS-CoV-2, along with a further nine tests that detect IgM-specific antibodies. All IgG or Total antibody tests reported a concordance with recent infection at 83.9% or greater, with 11/16 tests having greater than 90% sensitivity. All 16 tests reported greater than 96.3% specificity. There was a low level of false reactivity when testing all 25 tests on panels of samples containing potentially cross-reacting or interfering substances. A range of results were reported when testing seroconversion and dilution panels. The study further demonstrates that a comprehensive evaluation of the performance of test kits assessed against defined specifications is essential for the selection of test kits, especially in a pandemic setting.IMPORTANCEWe have previously highlighted the fact that hundreds of SARS-CoV-2 serology tests were released months after the onset of the COVID-19 pandemic. Of the hundreds of studies investigating the test kits' performance, few were comparative reports, using the same comprehensive sample set across multiple tests. Recently, we reported a comparative assessment of 35 rapid diagnostic tests (RDTs) or microtiter plate enzyme immunoassays (EIA) for use in low- and middle-income countries, using a large sample set from individuals with a history of COVID-19. Only a few tests meet WHO Target Product Profile performance requirements. This study reports on the performance of a further 25 automated SARS-CoV-2 immunoassays using the same panel of samples. The results highlight the better analytical and clinical performance of automated serology test kits compared with RDTs, and the importance of independent comparative assessments to inform the use and procurement of these tests for both diagnostic and epidemiological investigations. We have previously highlighted the fact that hundreds of SARS-CoV-2 serology tests were released months after the onset of the COVID-19 pandemic. Of the hundreds of studies investigating the test kits' performance, few were comparative reports, using the same comprehensive sample set across multiple tests. Recently, we reported a comparative assessment of 35 rapid diagnostic tests (RDTs) or microtiter plate enzyme immunoassays (EIA) for use in low- and middle-income countries, using a large sample set from individuals with a history of COVID-19. Only a few tests meet WHO Target Product Profile performance requirements. This study reports on the performance of a further 25 automated SARS-CoV-2 immunoassays using the same panel of samples. The results highlight the better analytical and clinical performance of automated serology test kits compared with RDTs, and the importance of independent comparative assessments to inform the use and procurement of these tests for both diagnostic and epidemiological investigations.