AUTHOR=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 TITLE=Serum antibody fingerprinting of SARS-CoV-2 variants in infected and vaccinated subjects by label-free microarray biosensor JOURNAL=Frontiers in Immunology VOLUME=15 YEAR=2024 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1323406 DOI=10.3389/fimmu.2024.1323406 ISSN=1664-3224 ABSTRACT=

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.