{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T04:30:59Z","timestamp":1772253059915,"version":"3.50.1"},"reference-count":31,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,3,9]],"date-time":"2022-03-09T00:00:00Z","timestamp":1646784000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Land Tirol","award":["Not available"],"award-info":[{"award-number":["Not available"]}]},{"name":"Tirol Kliniken GmbH","award":["Not available"],"award-info":[{"award-number":["Not available"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>There is uncertainty about the seroprevalence of anti-SARS-CoV-2 antibodies in the general population of Austria and about the waning of antibodies over time. We conducted a seroepidemiological study between June 2020 and September 2021, enrolling blood donors aged 18\u201370 years across Tyrol, Austria (participation rate: 84.0%). We analyzed serum samples for antibodies against the spike or the nucleocapsid proteins of SARS-CoV-2. We performed a total of 47,363 samples taken from 35,193 individuals (median age, 43.1 years (IQR: 29.3\u201353.7); 45.3% women; 10.0% with prior SARS-CoV-2 infection). Seroprevalence increased from 3.4% (95% CI: 2.8\u20134.2%) in June 2020 to 82.7% (95% CI: 81.4\u201383.8%) in September 2021, largely due to vaccination. Anti-spike IgG seroprevalence was 99.6% (95% CI: 99.4\u201399.7%) among fully vaccinated individuals, 90.4% (95% CI: 88.8\u201391.7%) among unvaccinated individuals with prior infection and 11.5% (95% CI: 10.8\u201312.3%) among unvaccinated individuals without known prior infection. Anti-spike IgG levels were reduced by 44.0% (95% CI: 34.9\u201351.7%) at 5\u20136 months compared with 0\u20133 months after infection. In fully vaccinated individuals, they decreased by 31.7% (95% CI: 29.4\u201333.9%) per month. In conclusion, seroprevalence in Tyrol increased to 82.7% in September 2021, with the bulk of seropositivity stemming from vaccination. Antibody levels substantially and gradually declined after vaccination or infection.<\/jats:p>","DOI":"10.3390\/v14030568","type":"journal-article","created":{"date-parts":[[2022,3,10]],"date-time":"2022-03-10T02:10:35Z","timestamp":1646878235000},"page":"568","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":26,"title":["Seroprevalence, Waning and Correlates of Anti-SARS-CoV-2 IgG Antibodies in Tyrol, Austria: Large-Scale Study of 35,193 Blood Donors Conducted between June 2020 and September 2021"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-7860-7144","authenticated-orcid":false,"given":"Anita","family":"Siller","sequence":"first","affiliation":[{"name":"Central Institute for Blood Transfusion and Immunology, Tirol Kliniken GmbH, 6020 Innsbruck, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lisa","family":"Seekircher","sequence":"additional","affiliation":[{"name":"Clinical Epidemiology Team, Medical University of Innsbruck, 6020 Innsbruck, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gregor A.","family":"Wachter","sequence":"additional","affiliation":[{"name":"Central Institute for Blood Transfusion and Immunology, Tirol Kliniken GmbH, 6020 Innsbruck, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manfred","family":"Astl","sequence":"additional","affiliation":[{"name":"Central Institute for Blood Transfusion and Immunology, Tirol Kliniken GmbH, 6020 Innsbruck, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7988-853X","authenticated-orcid":false,"given":"Lena","family":"Tschiderer","sequence":"additional","affiliation":[{"name":"Clinical Epidemiology Team, Medical University of Innsbruck, 6020 Innsbruck, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bernhard","family":"Pfeifer","sequence":"additional","affiliation":[{"name":"Department of Clinical Epidemiology, Tyrolean Federal Institute for Integrated Care, Tirol Kliniken GmbH, 6020 Innsbruck, Austria"},{"name":"Division for Healthcare Network and Telehealth, UMIT-Private University for Health Sciences, Medical Informatics and Technology GmbH, 6060 Hall, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manfred","family":"Gaber","sequence":"additional","affiliation":[{"name":"Blood Donor Service Tyrol of the Austrian Red Cross, 6063 Rum, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Harald","family":"Schennach","sequence":"additional","affiliation":[{"name":"Central Institute for Blood Transfusion and Immunology, Tirol Kliniken GmbH, 6020 Innsbruck, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1866-7159","authenticated-orcid":false,"given":"Peter","family":"Willeit","sequence":"additional","affiliation":[{"name":"Clinical Epidemiology Team, Medical University of Innsbruck, 6020 Innsbruck, Austria"},{"name":"Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,9]]},"reference":[{"key":"ref_1","unstructured":"Ritchie, H., Mathieu, E., Rod\u00e9s-Guirao, L., Appel, C., Giattino, C., Ortiz-Ospina, E., Hasell, J., Macdonald, B., Beltekian, D., and Roser, M. 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