Multiplexed, microscale, microarray-based serological assay for antibodies against all human-relevant coronaviruses.

Area of Science:

• Immunology
• Vaccinology
• Biotechnology

Background:

• Multiplexed serological assays are crucial for efficient COVID-19 vaccine development.
• Current methods may lack the speed, sensitivity, or precision required for streamlined clinical trials.

Purpose of the Study:

• To develop and validate a rapid, sensitive, and precise multiplexed assay for quantifying IgG antibody binding to diverse human coronavirus spike antigens.
• To assess the clinical performance of the assay in distinguishing between SARS-CoV-2 positive and negative samples.

Main Methods:

• The VaxArray Coronavirus (CoV) SeroAssay utilizes a microarray format with immobilized CoV spike antigens.
• Serum IgG antibodies are detected using a fluorescently labeled secondary antibody.
• Assay performance was evaluated for quantification limits, dynamic range, precision, and accuracy using replicates and clinical samples.

Main Results:

• The assay demonstrated excellent lower limits of quantification (0.3-2.0 ng/mL) and broad linear dynamic ranges (76-911-fold).
• High precision (11% CV) and accuracy (92.5% recovery) were achieved across multiple replicates and microarray lots.
• Clinical evaluation showed high performance with 98.5% positive percent agreement (PPA) and 100% negative percent agreement (NPA) for SARS-CoV-2 detection.

Conclusions:

• The VaxArray CoV SeroAssay provides a rapid (2-hour) and automated solution for multiplexed serological analysis.
• The assay's sensitivity, precision, and accuracy support its utility in vaccine development and clinical diagnostics.
• This multiplexed assay can quantify IgG antibodies against 9 pandemic, potentially pandemic, and endemic human CoV spike antigens.