2026-04-17T18:19:55Zhttps://recercat.cat/oai/request

oai:recercat.cat:10230/553222025-12-12T01:54:28Zcom_2072_6col_2072_452952

00925njm 22002777a 4500 dc Dobaño, Carlota author Ramírez Morros, Anna Maria author Alonso, Selena author Rubio, Rocío author Ruiz-Olalla, Gemma author Vidal Alaball, Josep author Macià, Dídac author Miró Catalina, Queralt author Vidal, Marta author Fuster Casanovas, Aina author Prados de la Torre, Esther author Barrios, Diana author Jiménez, Alfons author Zanoncello, Jasmina author Rodrigo Melero, Natalia author Carolis, Carlo author Izquierdo, Luis author Aguilar, Ruth author Moncunill, Gemma author Ruiz-Comellas, Anna author 2023-01-18T07:34:54Z 2023-01-18T07:34:54Z 2022 This study evaluated the persistence of IgM, IgA, and IgG to SARS-CoV-2 spike and nucleocapsid antigens up to 616 days since the onset of symptoms in a longitudinal cohort of 247 primary health care workers from Barcelona, Spain, followed up since the start of the pandemic. The study also assesses factors affecting antibody levels, including comorbidities and the responses to variants of concern as well as the frequency of reinfections. Despite a gradual and significant decline in antibody levels with time, seropositivity to five SARS-CoV-2 antigens combined was always higher than 90% over the whole study period. In a subset of 23 participants who had not yet been vaccinated by November 2021, seropositivity remained at 95.65% (47.83% IgM, 95.65% IgA, 95.65% IgG). IgG seropositivity against Alpha and Delta predominant variants was comparable to that against the Wuhan variant, while it was lower for Gamma and Beta (minority) variants and for IgA and IgM. Antibody levels at the time point closest to infection were associated with age, smoking, obesity, hospitalization, fever, anosmia/hypogeusia, chest pain, and hypertension in multivariable regression models. Up to 1 year later, just before the massive roll out of vaccination, antibody levels were associated with age, occupation, hospitalization, duration of symptoms, anosmia/hypogeusia, fever, and headache. In addition, tachycardia and cutaneous symptoms associated with slower antibody decay, and oxygen supply with faster antibody decay. Eight reinfections (3.23%) were detected in low responders, which is consistent with a sustained protective role for anti-spike naturally acquired antibodies. Stable persistence of IgG and IgA responses and cross-recognition of the predominant variants circulating in the 2020-2021 period indicate long-lasting and largely variant-transcending humoral immunity in the initial 20.5 months of the pandemic, in the absence of vaccination. The study received support from the Fundació Privada Daniel Bravo Andreu. Development of SARS-CoV-2 RBD was partially supported by the NIAID CEIRS contract HHSN272201400008C. L.I. work was supported by PID2019-110810RB-I00. E.P. was supported by a grant from the Junta de Andalucía/EU. R.R. had the support of the Health Department, Catalan Government (PERIS SLT017/20/000224). ISGlobal receives support from the Spanish Ministry of Science and Innovation through the “Centro de Excelencia Severo Ochoa 2019-2023” Program (CEX2018-000806-S) and support from the Generalitat de Catalunya through the CERCA Program. Funders were not involved in the study conduct, manuscript preparation, or submission. Antibody COVID-19 Duration Health care workers IgA IgG IgM Kinetics SARS-CoV-2 Seroprevalence Sustained seropositivity up to 20.5 months after COVID-19