SARS-CoV-2-specific antibody detection for sero-epidemiology: a multiplex analysis approach accounting for accurate seroprevalence

Abstract

Background The COVID-19 pandemic demands detailed understanding of the kinetics of antibody production induced by infection with SARS-CoV-2. We aimed to develop a high throughput multiplex assay to detect antibodies to SARS-CoV-2 to assess immunity to the virus in the general population. Methods Spike protein subunits S1 and RBD, and Nucleoprotein were coupled to distinct microspheres. Sera collected before the emergence of SARS-CoV-2 (N=224), and of non-SARS-CoV-2 influenza-like illness (N=184), and laboratory-confirmed cases of SARS-CoV-2 infection (N=115) with various severity of COVID-19 were tested for SARS-CoV-2-specific concentrations of IgG. Results Our assay discriminated SARS-CoV-2-induced antibodies and those induced by other viruses. The assay obtained a specificity between 95.1 and 99.0% with a sensitivity ranging from 83.6-95.7%. By merging the test results for all 3 antigens a specificity of 100% was achieved with a sensitivity of at least 90%. Hospitalized COVID-19 patients developed higher IgG concentrations and the rate of IgG production increased faster compared to non-hospitalized cases. Conclusions The bead-based serological assay for quantitation of SARS-CoV-2-specific antibodies proved to be robust and can be conducted in many laboratories. Finally, we demonstrated that testing of antibodies against different antigens increases sensitivity and specificity compared to single antigen-specific IgG determination.

Going beyond clinical routine in SARS-CoV-2 antibody testing - A multiplex corona virus antibody test for the evaluation of cross-reactivity to endemic coronavirus antigens

“…In our comparison to commercially available IVD tests, we classified fewer samples as false negative using our MultiCoV-Ab assay. For 10% of all infected samples, we could not detect a SARS-CoV-2 specific immune response, which is in line with previous findings 3,15,16 . Those non-responders may be able to limit viral replication by innate immune mechanisms or cellular immunity is dominant in mediating viral clearance 17,18 .…”

Seven-month kinetics of SARS-CoV-2 antibodies and protective role of pre-existing antibodies to seasonal human coronaviruses on COVID-19

“…IgA and IgM seroreversion was estimated between days 71 and 49, respectively 8 , but IgA has also been found to remain detectable 6 months post infection and to be less affected by the decay than IgM 9,10 . Several studies have observed relatively stable levels of IgG to the spike (S) protein after three 11,6 , four 12,13 and six to eight months 2,9,14-16 . However, others reported that IgG only lasted around 3-4 months PSO 17,18 .…”

Homologous and heterologous antibodies to coronavirus 229E, NL63, OC43, HKU1, SARS, MERS and SARS-CoV-2 antigens in an age stratified cross-sectional serosurvey in a large tertiary hospital in The Netherlands

“…Results of serological testing in a low prevalence situation need to be interpreted with caution, as low-level cross-reactivity has been observed for most currently available assays (6). A good practice can be to use combined assay results, counting only samples that had antibody reactivity to two or three of the SARS-CoV-2 antigens as positives(7). By using this criterion, and the high stringency cut-off defined by ROC analysis including serum samples form persons with recent seasonal coronavirus infections, we trust that our estimates are robust.…”