A multiplex antigen microarray for simultaneous IgG and IgM detection against SARS-CoV-2 reveals higher...

Area of Science:

• Immunology
• Virology
• Biotechnology

Background:

• The COVID-19 pandemic necessitates efficient diagnostic tools for detecting SARS-CoV-2 infection and immune responses.
• Existing serological tests often face limitations in sensitivity, specificity, promptness, or scalability.
• There is a need for advanced assays to monitor antibody levels for treatments and vaccine efficacy.

Purpose of the Study:

• To develop and validate SCOVAM, a protein microarray for comprehensive COVID-19 serological testing.
• To assess the sensitivity, specificity, and scalability of SCOVAM compared to established methods.
• To evaluate SCOVAM's utility in tracking antibody responses and prevalence over time.

Main Methods:

• Development of SCOVAM, a fluorescence immunoassay using a protein microarray with SARS-CoV-2 antigens (spike, nucleocapsid, Nsp5).
• Detection of specific IgG and IgM antibody responses against individual viral proteins.
• Validation of SCOVAM against a commercial chemiluminescent serological test using 742 serum samples.
• Analysis of seroconversion and prevalence in a subset of samples over four months.

Main Results:

• SCOVAM accurately detects specific IgM (0.094 μg ml⁻¹) and IgG (0.017 μg ml⁻¹) antibodies.
• The assay demonstrated twice the sensitivity of a commercial test in initial validation.
• SCOVAM successfully monitored seroconversion and detected 93.42% of positive sera four months post-infection, significantly outperforming the commercial assay.
• The protein microarray is scalable and cost-effective.

Conclusions:

• SCOVAM offers a highly sensitive and scalable solution for COVID-19 serological testing.
• Its superior sensitivity is crucial for screening convalescent plasma, monitoring vaccine responses, and evaluating vaccine efficiency.
• SCOVAM provides a valuable tool for understanding long-term antibody dynamics and disease prevalence.