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Anti-SARS-CoV-2 IgG Seroprevalence in Tyrol, Austria, among 28,768 Blood Donors between May 2022 and March 2023.

Published version
Peer-reviewed

Repository DOI


Change log

Authors

Astl, Manfred 
Wachter, Gregor A 

Abstract

BACKGROUND: To provide updated estimates on SARS-CoV-2 antibody seroprevalence and average antibody titres for Central Europe. METHODS: In repeat cross-sectional investigations (1 May 2022 to 9 March 2023) involving 28,768 blood donors in the Federal State of Tyrol, Austria (participation rate: 87.0%), we measured Spike receptor-binding domain (RBD) and Nucleocapsid IgG antibodies (37,065 and 12,645 samples), and estimated monthly seroprevalences and geometric mean titres. RESULTS: Median age of participants was 45.4 years (range 18-70); 43.2% were female. Spike RBD IgG antibody seroprevalence was 96.3% (95% CI: 95.6-96.9%) in May 2022, 97.4% (96.7-98.0%) in December 2022, and 97.9% (96.4-98.8%) in March 2023. Among seropositive participants, geometric mean titres increased from 1400 BAU/mL (95% CI: 1333-1471) in May 2022 to 1821 BAU/mL (1717-1932) in December 2022, and dropped to 1559 BAU/mL (1405-1729) by March 2023. Furthermore, titres differed markedly by vaccination status and history of infection, with being the highest in participants with booster vaccination and prior infection. In autumn 2022, Nucleocapsid IgG antibody seroprevalence ranged from 36.5% (35.0-38.1) in September to 39.2% (37.2-41.2) in December 2022. CONCLUSION: Seroprevalence of SARS-CoV-2 antibodies in blood donors from Tyrol, Austria, was remarkably stable from May 2022 to March 2023. In contrast, average Spike RBD IgG antibody titres peaked in December 2022.

Description

Peer reviewed: True


Acknowledgements: The authors thank the employees of the infection serology laboratory of the Central Institute for Blood Transfusion and Immunology, University Hospital Innsbruck, Tirol Kliniken GmbH, namely Barbara Schennach, Elfriede Lanser, Andrea Schiestl, and Michaela Szabo. We especially thank Barbara Schlögl, Helga Egger, Daniel Bichler, Tobias Christoph, Georg Schilcher, Roland Fuetsch, Jakob Stanger, Viliyana Kirova, Lukas Summerer, Bernhard Blanda, Katharina Lerchster, Karoline Kössler, Daniela Schmidt, Georg Kinzl, Andrea Schiestl, Johannes Köck, Oliver Nicoladoni, Theo Longo, Felix Koch, and Hans Peter Spötl for entering questionnaires into our database. Furthermore, we thank all employees of the blood donation service of the Tyrolean Red Cross.


Publication status: Published


Funder: Tirol Kliniken GmbH

Keywords

COVID-19, Nucleocapsid IgG antibodies, SARS-CoV-2 IgG antibodies, Spike IgG antibodies, blood donors, seroprevalence

Journal Title

Vaccines (Basel)

Conference Name

Journal ISSN

2076-393X
2076-393X

Volume Title

12

Publisher

MDPI AG
Sponsorship
Federal State of Tyrol (LSD-A-6/2/107-2021, ZI. FIN-1/103/1189-2021, LSD-A-6/2/131-2021, LSD-A-6/2/145-2022)