Multicentre Performance Evaluation of the Elecsys Anti-SARS-CoV-2 Immunoassay as an Aid in Determining Previous Exposure to SARS-CoV-2.

Introduction: We performed a multicentre evaluation of the Elecsys Anti-SARS-CoV-2 immunoassay (Roche Diagnostics), an assay utilising a recombinant protein representing the nucleocapsid (N) antigen, for the in vitro qualitative detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods: Specificity was evaluated using serum/plasma samples from blood donors and routine diagnostic specimens collected before September 2019 (i.e.

Mathematical Model to Assess Potential Reduced Specificity When Switching to New Screening Assays at Blood Donation Centers.

Background: Switching to new infectious disease blood donor screening assays can precipitate an initial decrease in specificity in an established donor population followed by an increase of specificity, referred to as a "cleaning effect". We developed a mathematical model to simulate this and to measure the stabilization of specificity.

Methods: A modified exponential distribution curve was created to show the impact of donation frequency on the cleaning of the donor pool.