biostudies-literatureNovelli SRoche DiagnosticsUniversity of BonnGovernment of BavariaNational Research Fund LuxembourgFrench Ministry for HealthGerman Ministry for Education and ResearchGerman Centre for Infection Research DZIFUniversity HospitalEuropean Union’s Horizon 2020Bavarian State Ministry of Science and the ArtsUniversity of BielefeldMikrogenRégion Ile-de-FranceAndré Losch FoundationLMU MunichAccentureBMWINSERMFrench Ministry for ResearchViramedEuroimmunDr. Box-BetroboxDr. Becker MVZDrees-Direction de la Recherche, des Etudes, de l’Evaluation et des StatistiquesMunich Policee0320196https://www.ebi.ac.uk/biostudies/studies/S-EPMC12063904biostudies-literatureUnknown20(5)<h4>Objectives</h4>We described waning in anti-SARS-CoV-2 IgG in adult general populations infected during the first wave of the COVID-19 pandemic in 2020 across three European countries.<h4>Methods</h4>Coordinated analyses were conducted separately in three population-based cohorts with complementary follow-up schedules: the KoCo19 (Germany), EpiCov (France), and CON-VINCE (Luxembourg) cohorts. Serological follow-up was based on the anti-SARS-CoV-2 ELISA-S IgG (Euroimmun) assay. We selected all adults aged 18-79 who had a positive serology (IgG optical density (OD) ratio ≥1.1) between February and July 2020, and at least one subsequent IgG measurement within the following 12 months, while still non-vaccinated.<h4>Results</h4>The proportion of seroreversion was 0% within the four first monPloS oneWaning of anti-SARS-CoV-2 antibodies after the first wave of the COVID-19 pandemic in 2020: A 12-month-evaluation in three population-based European studies.PMC1206390414716281NA01KI20271101016167Bulaev DBarthelemy KO'Sullivan MPKolodkin ACastelletti NHoelscher MWarszawski JReinkemeyer CMeyer LSnoeck CJKroidl IORCHESTRA Working Groupde Lamballerie XManto CGhosh Sle Chenadec JNovelli SKruger RVaillant MPriet SWieser ASatagopam VRauschenberger AfalseWaning of anti-SARS-CoV-2 antibodies after the first wave of the COVID-19 pandemic in 2020: A 12-month-evaluation in three population-based European studies.<h4>Objectives</h4>We described waning in anti-SARS-CoV-2 IgG in adult general populations infected during the first wave of the COVID-19 pandemic in 2020 across three European countries.<h4>Methods</h4>Coordinated analyses were conducted separately in three population-based cohorts with complementary follow-up schedules: the KoCo19 (Germany), EpiCov (France), and CON-VINCE (Luxembourg) cohorts. Serological follow-up was based on the anti-SARS-CoV-2 ELISA-S IgG (Euroimmun) assay. We selected all adults aged 18-79 who had a positive serology (IgG optical density (OD) ratio ≥1.1) between February and July 2020, and at least one subsequent IgG measurement within the following 12 months, while still non-vaccinated.<h4>Results</h4>The proportion of seroreversion was 0% within the four first mon2025-01-01T00:00:00Z20252026-06-02T12:08:58.929Z2026-04-18T03:11:05.538ZS-EPMC120639044034414510.1371/journal.pone.0320196