A Trans-Governmental Collaboration to Independently Evaluate SARS-CoV-2 Serology Assays.

The emergence of SARS-CoV-2 created a crucial need for serology assays to detect anti-SARS-CoV-2 antibodies, which led to many serology assays entering the market. A trans-government collaboration was created in April 2020 to independently evaluate the performance of commercial SARS-CoV-2 serology assays and help inform U.S. Food and Drug Administration (FDA) regulatory decisions. To assess assay performance, three evaluation panels with similar antibody titer distributions were assembled. Each panel consisted of 110 samples with positive (n = 30) serum samples with a wide range of anti-SARS-CoV-2 antibody titers and negative (n = 80) plasma and/or serum samples that were collected before the start of the COVID-19 pandemic. Each sample was characterized for anti-SARS-CoV-2 antibodies against the spike protein using enzyme-linked immunosorbent assays (ELISA). Samples were selected for the panel when there was agreement on seropositivity by laboratories at National Cancer Institute's Frederick National Laboratory for Cancer Research (NCI-FNLCR) and Centers for Disease Control and Prevention (CDC). The sensitivity and specificity of each assay were assessed to determine Emergency Use Authorization (EUA) suitability. As of January 8, 2021, results from 91 evaluations were made publicly available (https://open.fda.gov/apis/device/covid19serology/, and https://www.cdc.gov/coronavirus/2019-ncov/covid-data/serology-surveillance/serology-test-evaluation.html). Sensitivity ranged from 27% to 100% for IgG (n = 81), from 10% to 100% for IgM (n = 74), and from 73% to 100% for total or pan-immunoglobulins (n = 5). The combined specificity ranged from 58% to 100% (n = 91). Approximately one-third (n = 27) of the assays evaluated are now authorized by FDA for emergency use. This collaboration established a framework for assay performance evaluation that could be used for future outbreaks and could serve as a model for other technologies. IMPORTANCE The SARS-CoV-2 pandemic created a crucial need for accurate serology assays to evaluate seroprevalence and antiviral immune responses. The initial flood of serology assays entering the market with inadequate performance emphasized the need for independent evaluation of commercial SARS-CoV-2 antibody assays using performance evaluation panels to determine suitability for use under EUA. Through a government-wide collaborative network, 91 commercial SARS-CoV-2 serology assay evaluations were performed. Three evaluation panels with similar overall antibody titer distributions were assembled to evaluate performance. Nearly one-third of the assays evaluated met acceptable performance recommendations, and two assays had EUAs revoked and were removed from the U.S. market based on inadequate performance. Data for all serology assays evaluated are available at the FDA and CDC websites (https://open.fda.gov/apis/device/covid19serology/, and https://www.cdc.gov/coronavirus/2019-ncov/covid-data/serology-surveillance/serology-test-evaluation.html).

Quantitative High-Throughput Screening Using a Coincidence Reporter Biocircuit.

Reporter-biased artifacts-i.e., compounds that interact directly with the reporter enzyme used in a high-throughput screening (HTS) assay and not the biological process or pharmacology being interrogated-are now widely recognized to reduce the efficiency and quality of HTS used for chemical probe and therapeutic development. Furthermore, narrow or single-concentration HTS perpetuates false negatives during primary screening campaigns. Titration-based HTS, or quantitative HTS (qHTS), and coincidence reporter technology can be employed to reduce false negatives and false positives, respectively, thereby increasing the quality and efficiency of primary screening efforts, where the number of compounds investigated can range from tens of thousands to millions. The three protocols described here allow for generation of a coincidence reporter (CR) biocircuit to interrogate a biological or pharmacological question of interest, generation of a stable cell line expressing the CR biocircuit, and qHTS using the CR biocircuit to efficiently identify high-quality biologically active small molecules. © 2017 by John Wiley & Sons, Inc.