Serum antibody fingerprinting of SARS-CoV-2 variants in infected and vaccinated subjects by label-free microarray biosensor

• Published in: Frontiers in immunology Vol. 15; p. 1323406
• Main Authors: Carzaniga, Thomas, Casiraghi, Luca, Nava, Giovanni, Zanchetta, Giuliano, Inzani, Tommaso, Chiari, Marcella, Bollati, Valentina, Epis, Sara, Bandi, Claudio, Lai, Alessia, Zehender, Gianguglielmo, Bellini, Tommaso, Buscaglia, Marco
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 27.02.2024
• Subjects: antibody repertoire; Immunology; label-free biosensor; rapid detection; reflective phantom interface; serological assay; wash-free assay; wash-free assay; IgA; label-free biosensor; reflective phantom interface; rapid detection; immunoglobulins; serological assay; antibody repertoire
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2024.1323406

Both viral infection and vaccination affect the antibody repertoire of a person. Here, we demonstrate that the analysis of serum antibodies generates information not only on the virus type that caused the infection but also on the specific virus variant. We developed a rapid multiplex assay providing a fingerprint of serum antibodies against five different SARS-CoV-2 variants based on a microarray of virus antigens immobilized on the surface of a label-free reflectometric biosensor. We analyzed serum from the plasma of convalescent subjects and vaccinated volunteers and extracted individual antibody profiles of both total immunoglobulin Ig and IgA fractions. We found that Ig level profiles were strongly correlated with the specific variant of infection or vaccination and that vaccinated subjects displayed a larger quantity of total Ig and a lower fraction of IgA relative to the population of convalescent unvaccinated subjects.