RESUMO
IntroductionMolecular testing for SARS-CoV-2 continues to suffer from delays and shortages. Antigen tests have recently emerged as a viable alternative to detect patients with high viral loads, associated with elevated risk of transmission. While rapid lateral flow tests greatly improved accessibility of SARS-CoV-2 detection in critical areas, their manual nature limits scalability and suitability for large-scale testing schemes. The Elecsys(R) SARS-CoV-2 Antigen assay allows antigen immunoassays to be carried out on fully automated high-throughput serology platforms. MethodsA total of 3139 nasopharyngeal and oropharyngeal swabs were collected at 3 different testing sites in Germany. Swab samples were pre-characterized by RT-qPCR and consecutively subjected to the antigen immunoassay on either the cobas e 411 or cobas e 801 analyzers. ResultsOf the tested respiratory samples, 392 were PCR positive for SARS-CoV-2 RNA. Median concentration was 2.95x104 (interquartile range [IQR] 5.1x102-3.5x106) copies/mL. Overall sensitivity and specificity of the antigen immunoassay were 60.2% (95% confidence interval [CI] 55.2-65.1) and 99.9% (95% CI 99.6-100), respectively. A 93.7% (95% CI 89.7-96.5) sensitivity was achieved at a viral RNA concentration [≥]104 copies/mL ([~]cycle threshold (Ct) value<29.9). ConclusionThe Elecsys SARS-CoV-2 Antigen assay reliably detected patient samples with viral loads of 10,000 copies/mL and higher. It thus represents a viable high-throughput alternative for screening of patients, or in situations where PCR testing is not readily available. Key Summary PointsO_ST_ABSWhy carry out this study?C_ST_ABSO_LIThe SARS-CoV-2 pandemic has led to a surge in demand for reliable, mass diagnostic tests worldwide. C_LIO_LIA thorough clinical evaluation of a fully automated high-throughput Elecsys(R) SARS-CoV-2 Antigen assay on a total of 3139 clinical samples pre-characterized by quantitative RT-PCR was carried out. C_LI What was learned from the study?O_LIThe assay demonstrated excellent specificity (99.9%) and good relative sensitivity, with an overall sensitivity of 60.2% and a sensitivity of 93.7% for samples containing [≥]104 viral RNA copies/mL. C_LIO_LIThe Elecsys SARS-CoV-2 Antigen assay is a viable high-throughput, automated alternative to manual lateral-flow antigen tests. C_LI
