Karachaliou, MariannaMoncunill Piñas, GemmaEspinosa, AnaCastaño-Vinyals, GemmaJiménez, AlfonsVidal, MartaSantano, RebecaBarrios, DianaPuyol, LauraCarreras, AnnaMayer, LeonieRubio, RocíoCortés, BeatrizPleguezuelos, VanessaO'Callaghan Gordo, CristinaFossati, SerenaRivas, IoarCasabonne, DelphineVrijheid, MartineIzquierdo Lázaro, LuisAguilar, RuthBasagaña, XavierGarcía Aymerich, JudithCid, Rafael deDobaño, Carlota, 1969-Kogevinas, Manolis2021-11-182021-11-182021-11-03https://hdl.handle.net/2445/181352Sparse data exist on the complex natural immunity to SARS-CoV-2 at the population level. We applied a well-validated multiplex serology test in 5000 participants of a general population study in Catalonia in blood samples collected from end June to mid November 2020. Based on responses to fifteen isotype-antigen combinations, we detected a seroprevalence of 18.1% in adults (n = 4740), and modeled extrapolation to the general population of Catalonia indicated a 15.3% seroprevalence. Antibodies persisted up to 9 months after infection. Immune profiling of infected individuals revealed that with increasing severity of infection (asymptomatic, 1-3 symptoms, ≥ 4 symptoms, admitted to hospital/ICU), seroresponses were more robust and rich with a shift towards IgG over IgA and anti-spike over anti-nucleocapsid responses. Among seropositive participants, lower antibody levels were observed for those ≥ 60 years vs < 60 years old and smokers vs non-smokers. Overweight/obese participants vs normal weight had higher antibody levels. Adolescents (13-15 years old) (n = 260) showed a seroprevalence of 11.5%, were less likely to be tested seropositive compared to their parents and had dominant anti-spike rather than anti-nucleocapsid IgG responses. Our study provides an unbiased estimate of SARS-CoV-2 seroprevalence in Catalonia and new evidence on the durability and heterogeneity of post-infection immunity.application/pdfengcc-by (c) Karachaliou, Marianna et al., 2021http://creativecommons.org/licenses/by/4.0/COVID-19EpidemiologiaCatalunyaCOVID-19EpidemiologyCataloniainfo:eu-repo/semantics/publishedVersion2021-11-18info:eu-repo/semantics/openAccess34732749