Alvarez-Sierra, DanielMartínez-Gallo, MónicaSánchez-Montalvá, AdriánFernández Sanmartín, Marco-AntonioColobran, RogerEspinosa-Pereiro, JuanPoyatos-Canton, ElisabetZurera-Egea, CoralSànchez, Àlex (Sànchez Pla)Violán, ConcepciónParra, RafaelAlzayat, HammadVivancos, AnaMorandeira-Rego, FranciscoUrban-Vargas, BlancaMartínez-Cáceres, EvaHernández-González, ManuelBas Minguet, JordiKatsikis, PeterTeniente-Serra, AinaPujol Borrell, Ricardo2025-06-062025-06-062025-03-011521-6616https://hdl.handle.net/2445/221437The antibody response to SARS-CoV-2 does not follow the immunoglobulin isotype pattern of primary responses, conflicting with the current interpretation of COVID-19. Methods: Prospective cohort study of 191 SARS-CoV-2 infection cases and 44 controls from the second wave of COVID-19. The study stratified patients by severity and analyzed the trajectories of SARS-CoV-2 antibodies and multiple immune variables. Results: Isotype-specific antibody time course profiles to SARS-CoV-2 revealed a pattern of recall response in 94.2 % of cases. The time course profiles of plasmablasts, B cells, cTfh high-resolution subsets, and cytokines indicated a secondary response. The transcriptomic data showed that this cohort is strictly comparable to contemporary cohorts. Conclusions: In most cases, the immune response to SARS-CoV-2 is a recall response. This constitutes a favorable scenario for most COVID-19 cases to be subjected to immune imprinting by endemic coronavirus, which, in turn, can influence the immune response to SARS-CoV-2.17 p.application/pdfengcc-by-nc (c) Alvarez-Sierra, Daniel et al., 2025https://creativecommons.org/licenses/by-nc/4.0/COVID-19AdultsImmunoglobulinesLimfòcitsCOVID-19AdulthoodImmunoglobulinsLymphocytesinfo:eu-repo/semantics/article7587812025-06-06info:eu-repo/semantics/openAccess39842683