Qualification of ELISA and neutralization methodologies to measure SARS-CoV-2 humoral immunity using human clinical samples

Abstract

In response to the SARS-CoV-2 pandemic many vaccines have been developed and evaluated in human clinical trials. The humoral immune response magnitude, composition and efficacy of neutralizing SARS-CoV-2 are essential endpoints for these trials. Robust assays that are reproducibly precise, linear, and specific for SARS-CoV-2 antigens would be beneficial for the vaccine pipeline. In this work we describe the methodologies and clinical qualification of three SARS-CoV-2 endpoint assays. We developed and qualified Endpoint titer ELISAs for total IgG, IgG1, IgG3, IgG4, IgM and IgA to evaluate the magnitude of specific responses to the trimeric spike (S) antigen and total IgG specific to the spike receptor binding domain (RBD) of SARS-CoV-2. We also qualified a pseudovirus neutralization assay which evaluates functional antibody titers capable of inhibiting the entry and replication of a lentivirus containing the Spike antigen of SARS-CoV-2. To complete the suite of assays we qualified a plaque reduction neutralization test (PRNT) methodology using the 2019-nCoV/USA-WA1/2020 isolate of SARS-CoV-2 to assess neutralizing titers of antibodies in plasma from normal healthy donors and convalescent COVID-19 individuals.

A Comparative and Comprehensive Review of Antibody Applications in the Treatment of Lung Disease

“…The titers of neutralizing antibodies also play a significant role. The low titer of neutralizing antibodies in recovered COVID-19 patients was the main reason for the failure of a recent convalescent plasma clinical trial [46]. It is also the reason for the failure of convalescent plasma therapy, i.e., the transfer of neutralizing antibody-containing plasma from recovered patients to patients in need.…”

Ag Nanoparticles with Ultrathin Au Shell-Based Lateral Flow Immunoassay for Colorimetric and SERS Dual-Mode Detection of SARS-CoV-2 IgG

“… 10 , 11 Besides, IgG detection helps to study the mechanism of infection. 12 At present, enzyme-linked immunosorbent assay (ELISA) 13 and chemiluminescence immunoassay (CI) 14 are the main clinical methods for detection of antibodies. These methods have acceptable sensitivity and quantification advantages.…”

“…Moreover, serological test is the essential link to accurately diagnose the disease progression of SARS-CoV-2 infection, which helps to provide guidance for choosing suitable treatment and evaluate the treatment effect. , Besides, IgG detection helps to study the mechanism of infection . At present, enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassay (CI) are the main clinical methods for detection of antibodies. These methods have acceptable sensitivity and quantification advantages.…”

Sensitive and specific clinically diagnosis of SARS-CoV-2 employing a novel biosensor based on boron nitride quantum dots/flower-like gold nanostructures signal amplification

“…Nevertheless, RT-PCR test for SARS-CoV-2 detection is prone to false-negative results as well as the need for well-trained professionals, expensive instruments and equipped laboratories, limits of flexibility, slow diagnostic (3–4h), labor-intensive, and costly make the RT-PCR method vulnerable ( Surkova et al, 2020 ; Xie et al, 2020 ). Apart from that, enzyme-linked immunosorbent analysis (ELISA) has also been established for rapid recognition of SARS-CoV-2 ( Laidoudi et al, 2021 ; Larsen et al, 2021 ). Serological analysis require minimal equipment and are readily available.…”