Performance of multiplex bead based assay for detection of neutralizing antibodies in SARS CoV-2 infected and vaccinated individuals

ABSTRACT

Background: After the pandemic of SARS COV2 it is evolving and causing a threat and concern worldwide. Studies on variants are crucial in understanding the change in virulence and transmissibility of the virus and further vaccine efficacy. Plaque reduction neutralization test (PRNT) is the gold standard to detect neutralizing antibodies. Consequently, it is essential to explore other neutralization platforms which give promising results with quick turnaround time and safety compared to live neutralization assay. Objective(s) To compare and evaluate the neutralizing antibody responses of a multiplex bead-based assay (MBA), using the SARSCoV- 2 Variants Neutralizing Antibody Human 5-Plex ProcartaPlexTM Panel, with PRNT and further evaluate it to estimate the neutralizing responses in infected and vaccinated individuals. Material(s) and Method(s) Confirmed RT PCR covid positive and serum samples from vaccinated individuals (Covaxin and Covishield) were assesssed for the presence of neutralizing antibodies using Multiplex bead assay Human 5-Plex ProcartaPlexTM kit. Result(s) The sensitivity and specificity of MBA was less as compared to PRNT. In our study, we observed that qualitative assay was more comparable than quantitative assay. Conclusion(s) This study demonstrated the utility of MBA for simultaneous measurement of neutralizing antibodies against multiple SARS-CoV-2 strains in serum. The qualitative assay performance was imparted excellent with high sensitivity and specificity but variation in quantitative titres was observed compared to live neutralization assay titres.