Validation of High-Throughput, Semiquantitative Solid-Phase Sarscoronavirus-2 Serology Assays in Serum and Dried Blood Spot Matrices

Abstract

<b>Aim:</b> Serological assays for the detection of anti-SARS coronavirus-2 (SARS-CoV-2) antibodies are essential to the response to the global pandemic. A ligand binding-based serological assay was validated for the semiquantitative detection of IgG, IgM, IgA and neutralizing antibodies (nAb) against SARS-CoV-2 in serum. <b>Results:</b> The assay demonstrated high levels of diagnostic specificity and sensitivity (85-99% for all analytes). Serum IgG, IgM, IgA and nAb correlated positively (R² = 0.937, R² = 0.839, R² = 0.939 and R² = 0.501, p < 0.001, respectively) with those measured in dried blood spot samples collected using the hemaPEN^® microsampling device (Trajan Scientific and Medical, Victoria, Australia). <i>In vitro</i> SARS-CoV-2 pseudotype neutralization correlated positively with the solid phase nAb signals in convalescent donors (R² = 0.458, p < 0.05). <b>Conclusion:</b> The assay is applicable in efficacy studies, infection monitoring and postmarketing surveillance following vaccine rollout.