Performance of a high-throughput, automated enzyme immunoassay for the detection of SARS-CoV-2 antigen, including in viral “variants of concern”: Implications for clinical use

• Published in: Journal of clinical virology Vol. 146; p. 105048
• Main Authors: Fourati, Slim, Soulier, Alexandre, Gourgeon, Aurélie, Khouider, Souraya, Langlois, Camille, Galbin, Arnaud, Bouter, Anne Le, Rodriguez, Christophe, Joanny, Marie, Dublineau, Amélie, Challine, Dominique, Bouvier-Alias, Magali, Chevaliez, Stéphane, Audureau, Étienne, Pawlotsky, Jean-Michel
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2022
• Subjects: Antigen test; Antigens, Viral; COVID-19; EIA; Humans; Immunoassay; Immunoenzyme Techniques; Retrospective Studies; RNA, Viral; SARS CoV-2; Sensitivity; Sensitivity and Specificity; Specificity; Variants of concern; Antigen test; Variants of concern; Sensitivity; Specificity; SARS CoV-2; EIA
• ISSN: 1386-6532; 1873-5967; 1873-5967
• DOI: 10.1016/j.jcv.2021.105048

•In this study, we show that EIA-based antigen tests have the potential to be a game-changer in COVID-19 diagnosis with simplicity, low cost, high-throughput capacity and rapidity of results enabling to considerably increase the diagnostic capabilities of biology laboratories. Direct detection of SARS-CoV-2 viral antigens could replace RT-PCR, provided that its clinical performance is validated in different epidemiological settings. Here, we evaluated the performance of the VITROS Antigen test, an enzyme immunoassay detecting a SARS-CoV-2 antigen, in NPSs from 3 cohorts of patients. : Three cohorts including SARS-CoV-2 RNA-positive samples collected during the first and second wave of the French epidemic between March 2020 and February 2021 (including variant B.1.1.7/α and variant B.1.351/β). : Among the 1763 prospectively tested subjects, 8.2% (145/1763) were SARS-CoV-2 RNA-positive by RT-PCR. Using Ct ≤ 30 and Ct ≤ 35 as thresholds, the sensitivities of the antigen assay were 98.8% (93.6–100%) and 93.5% (87.0–97.3%), respectively. The overall specificity of the assay was 100% (1614/1614; 99.8–100%). In a retrospective cohort of subjects infected with variants of concern, 90.4% (47/52) of NPSs containing B. B.1.1.7/α (Ct ≤ 35) and 100% (7/7) of those containing B.1.351/β were positive with the VITROS EIA SARS-CoV-2 Antigen test. : The excellent performance of the EIA Antigen test reported here, including in patients infected with viral “variants of concern”, support the use of high-throughput, EIA-based SARS-CoV-2 antigen assays as an alternative or complement to nucleic acid testing in order to scale-up laboratory screening and diagnostic capacities.