A Novel Quantitative Multi-Component Serological Assay for SARS-CoV-2 Vaccine Evaluation

Area of Science:

• Immunology
• Vaccinology
• Biotechnology

Background:

• Accurate quantification of vaccine-induced immune responses is crucial for evaluating vaccine efficacy.
• Existing methods may not simultaneously assess multiple immunoglobulin isotypes against various SARS-CoV-2 antigens.
• The need for a standardized and reliable assay for immunogenicity testing is critical.

Purpose of the Study:

• To develop and validate a multi-component microarray assay for quantitative evaluation of SARS-CoV-2 vaccine immunogenicity.
• To enable simultaneous measurement of IgG, IgM, and IgA antibodies specific to SARS-CoV-2 spike, receptor binding domain, and nucleocapsid proteins.
• To assess the performance characteristics (linearity, dynamic range, specificity, precision, accuracy) of the developed microarray assay.

Main Methods:

• Development of a multi-component microarray for simultaneous detection of SARS-CoV-2 specific IgG, IgM, and IgA.
• Application of a novel analysis algorithm to calculate normalized immunoglobulin signals from fluorescent read-outs.
• Quantification of apparent immunoglobulin signals from the linear range of microarray scans at different exposure times.
• Validation of the assay using in-house positive and commercial negative sera, compared against the WHO international standard.

Main Results:

• The microarray assay successfully quantified specific IgG, IgM, and IgA antibodies against SARS-CoV-2 proteins.
• The developed algorithm provided normalized signals, ensuring assay reliability and comparability.
• The assay demonstrated good performance characteristics, including linearity, extended dynamic range, specificity, precision, and accuracy.
• Successful discrimination between seroconverted COVID-19 patients and naive individuals was achieved.

Conclusions:

• The novel multi-component microarray assay provides a quantitative and reliable method for evaluating SARS-CoV-2 vaccine immunogenicity.
• The assay enables simultaneous assessment of humoral immune responses, including different antibody isotypes against key viral proteins.
• This validated platform is currently utilized in clinical trials to assess the immune response to the BriLife vaccine.