Evaluation of the performance of multiple immunoassay diagnostic platforms on the National Microbiology Laboratory SARS-CoV-2 National Serology Panel

Abstract

BACKGROUND: Serological assays designed to detect SARS-CoV-2 antibodies are being used in serological surveys and other specialized applications. As a result, and to ensure that the outcomes of serological testing meet high quality standards, evaluations are required to assess the performance of these assays and the proficiency of laboratories performing them. METHODS: A panel of 60 plasma/serum samples from blood donors who had Real Time-Polymerase Chain Reaction (RT-PCR) confirmed SARS-CoV-2 infections and 21 SARS-CoV-2 negative samples were secured and distributed to interested laboratories within Canada ( n = 30) and the United States ( n = 1). Participating laboratories were asked to provide details on the diagnostic assays used, the platforms the assays were performed on, and the results obtained for each panel sample. Laboratories were blinded with respect to the expected outcomes. RESULTS: The performance of the different assays evaluated was excellent, with the high-throughput platforms of Roche, Ortho, and Siemens demonstrating 100% sensitivity. Most other high-throughput platforms had sensitivities of >93%, with the exception of the IgG assay using the Abbott ARCHITECT which had an average sensitivity of only 87%. The majority of the high-throughput platforms also demonstrated very good specificities (>97%). CONCLUSION: This proficiency study demonstrates that most of the SARS-CoV-2 serological assays utilized by provincial public health or hospital laboratories in Canada have acceptable sensitivity and excellent specificity.

Symptomatology during previous SARS-CoV-2 infection and serostatus before vaccination influence the immunogenicity of BNT162b2 COVID-19 mRNA vaccine

“…Seropositivity was defined as an OD 490 ratio greater than one with the experimentally determined cut-off, which corresponds to the mean of 10 negative controls plus three times the standard deviation of the negative controls for each experiment. This anti-RBD IgG ELISA was validated on the Canadian National Microbiology Laboratory SARS-CoV-2 National Serology Panel (23,26). Absence of previous infection to SARS-CoV-2 was confirmed in the naïve cohort by performing an ELISA detecting specific IgG antibodies for the Nucleoprotein (anti-N) of SARS-CoV-2 and the anti-RBD ELISA before vaccination.…”

Lessons Learned from the COVID-19 Pandemic and How Blood Operators Can Prepare for the Next Pandemic

“…The COVID-19 pandemic has impacted on all elements of society. Blood operators have played an important role in studying and characterizing the COVID-19 pandemic and can provide lessons learned from this experience [ 10 , 11 , 12 , 13 , 14 ].…”