Can commercial automated immunoassays be utilized to predict neutralizing antibodies after SARS-CoV-2 infection? A comparative study between three different assays

Background: High-throughput assays that can infer neutralizing activity against SARS-CoV-2 are of great importance for assessing the immunity induced by natural infection and COVID-19 vaccines. We aimed to evaluate performance degree correlation three fully automated anti-SARS-CoV-2 immunoassays with neutralization using a surrogate virus-neutralizing test (sVNT) from GenScript, targeting receptor-binding domain. Methods: 110 sera collected PCR-confirmed asymptomatic individuals were tested antibodies (nAbs) sVNT. Positive samples on different viral antigens: Mindray CL-900i®, Abbott Architect, Ortho VITROS®. The diagnostic sensitivity, specificity, agreement, sVNT assessed. Receiver operating characteristic (ROC) curve analysis was performed determine optimal thresholds predicting presence each assay. Results: All showed 100% specificities. highest sensitivity 99.0%, demonstrated VITROS®, followed 94.3%, 81.0%, Architect. Both VITROS® CL-900i® had strongest (ρ = 0.718 ρ 0.712, respectively), while Architect moderate 0.618). ROC indicated manufacturer’s recommended cutoff values adequate nAbs providing strong Conclusion: serological assays, which detect spike protein, could serve as reliable predict after or vaccination.