A Comparative Study of Nine SARS-CoV-2 IgG Lateral Flow Assays Using Both Post-Infection and Post-Vaccination...

Area of Science:

• Immunology
• Infectious Diseases
• Diagnostic Assay Development

Background:

• Numerous SARS-CoV-2 antibody lateral flow assays (LFAs) are available, but antigen composition and performance data are often incomplete.
• CE-IVD labeling does not guarantee comprehensive performance characteristics or detailed sample information for LFAs.
• Lack of standardized verification hinders reliable assessment of SARS-CoV-2 antibody LFAs.

Purpose of the Study:

• To comparatively evaluate nine lateral flow assays for detecting SARS-CoV-2 IgG antibodies.
• To assess assay performance using a diverse serum panel including post-infection and post-vaccination samples.
• To identify antigens used in LFAs and understand performance variations.

Main Methods:

• Comparative evaluation of nine commercially available SARS-CoV-2 IgG lateral flow assays.
• Utilized a serum panel with samples from individuals post-infection and post-vaccination (mRNA and inactivated virus vaccines).
• Analyzed sensitivity and specificity, correlating results with assay antigen composition (Spike vs. Nucleocapsid protein).

Main Results:

• Assay sensitivity ranged from 9% to 90.3%, with specificity from 94.2% to 100%.
• LFAs utilizing Spike protein generally outperformed those using only Nucleocapsid protein.
• Sensitivity varied significantly between post-infection and post-vaccination samples for different assays.

Conclusions:

• Comparative verification with a well-designed serum panel aids in identifying assay antigens.
• Assay performance is dependent on the sample type (post-infection vs. post-vaccination).
• Verification protocols must use samples representative of the intended clinical application for accurate LFA assessment.