Since the outbreak of the Covid-19 pandemic, the development of diagnostics for both the virus (molecular) and the host immune response (serological) has become essential for monitoring the spread of the disease, monitoring those that have been infected (often with little or no symptoms) and monitoring the recovery of survivors.  In the current climate, with a new disease and quickly released products, sensitivity and specificity are major concerns for all of these diagnostic modalities.

The immune response to SARS-CoV2 is still poorly understood.  It is unknown which antigens (if any) may correlate with protective immunity.  Most current serological assays are limited in their ability to monitor and distinguish multiple markers in a single patient sample.  With the importance of measuring the antibody responses of patients exposed to Covid-19, the need for an accurate, rapid assay that is versatile enough to respond to our quickly evolving knowledge of this illness is in high demand.

This presentation describes the development of a rapid multiplex serological assay.  Antibody responses to the SARS-CoV-2 Spike (S), receptor binding domain (RBD) and nucleocapsid (NP) antigens are measured in a 96 well format with as little as 10ul of patient serum.  A full 96 well plate with samples and controls can be processed in about 45 minutes with a read time of around 20 minutes. This assay was found to be both highly sensitive (92% by day 16) and specific (100%).

Learning Objectives:

1. Understand the components of a microsphere multiplex immunoassay

2. Understand how a multiplexed assay can answer questions about the serological response to SARS-CoV-2