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

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

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

Peer reviewed: TrueAcknowledgements: 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: PublishedFunder: Tirol Kliniken GmbHBACKGROUND: 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

Biphasic Metabolism and Host Interaction of a Chlamydial Symbiont

Chlamydiae are obligate intracellular bacteria comprising well-known human pathogens and ubiquitous symbionts of protists, which are characterized by a unique developmental cycle. Here we comprehensively analyzed gene expression dynamics of Protochlamydia amoebophila during infection of its Acanthamoeba host by RNA sequencing. This revealed a highly dynamic transcriptional landscape, where major transcriptional shifts are conserved among chlamydial symbionts and pathogens. Our data served to propose a time-resolved model for type III protein secretion during the developmental cycle, and we provide evidence for a biphasic metabolism of P. amoebophila during infection, which involves energy parasitism and amino acids as the carbon source during initial stages and a postreplicative switch to endogenous glucose-based ATP production. This fits well with major transcriptional changes in the amoeba host, where upregulation of complex sugar breakdown precedes the P. amoebophila metabolic switch. The biphasic chlamydial metabolism represents a unique adaptation to exploit eukaryotic host cells, which likely contributed to the evolutionary success of this group of microbes.This article is published as König L, Siegl A, Penz T, Haider S, Wentrup C, Polzin J, Mann E, Schmitz-Esser S, Domman D, Horn M. 2017. Biphasic metabolism and host interaction of a chlamydial symbiont. mSystems 2:e00202-16. doi: 10.1128/mSystems.00202-16.</p

Anti‐Spike IgG antibodies as correlates of protection against SARS‐CoV‐2 infection in the pre‐Omicron and Omicron era

Publication status: PublishedFunder: University Hospital InnsbruckFunder: Federal State of TyrolAbstractAnti‐Spike IgG antibodies against SARS‐CoV‐2, which are elicited by vaccination and infection, are correlates of protection against infection with pre‐Omicron variants. Whether this association can be generalized to infections with Omicron variants is unclear. We conducted a retrospective cohort study with 8457 blood donors in Tyrol, Austria, analyzing 15,340 anti‐Spike IgG antibody measurements from March 2021 to December 2022 assessed by Abbott SARS‐CoV‐2 IgG II chemiluminescent microparticle immunoassay. Using a Bayesian joint model, we estimated antibody trajectories and adjusted hazard ratios for incident SARS‐CoV‐2 infection ascertained by self‐report or seroconversion of anti‐Nucleocapsid antibodies. At the time of their earliest available anti‐Spike IgG antibody measurement (median November 23, 2021), participants had a median age of 46.0 years (IQR 32.8–55.2), with 45.3% being female, 41.3% having a prior SARS‐CoV‐2 infection, and 75.5% having received at least one dose of a COVID‐19 vaccine. Among 6159 participants with endpoint data, 3700 incident SARS‐CoV‐2 infections with predominantly Omicron sublineages were recorded over a median of 8.8 months (IQR 5.7–12.4). The age‐ and sex‐adjusted hazard ratio for SARS‐CoV‐2 associated with having twice the anti‐Spike IgG antibody titer was 0.875 (95% credible interval 0.868–0.881) overall, 0.842 (0.827–0.856) during 2021, and 0.884 (0.877–0.891) during 2022 (all p &lt; 0.001). The associations were similar in females and males (Pinteraction = 0.673) and across age (Pinteraction = 0.590). Higher anti‐Spike IgG antibody titers were associated with reduced risk of incident SARS‐CoV‐2 infection across the entire observation period. While the magnitude of association was slightly weakened in the Omicron era, anti‐Spike IgG antibody continues to be a suitable correlate of protection against newer SARS‐CoV‐2 variants.</jats:p

Definition and terminology of developmental language disorders-Interdisciplinary consensus across German-speaking countries.

In recent years, there have been intense international discussions about the definition and terminology of language disorders in childhood, such as those sparked by the publications of the CATALISE consortium. To address this ongoing debate, a Delphi study was conducted in German-speaking countries. This study consisted of three survey waves and involved over 400 experts from relevant disciplines. As a result, a far-reaching consensus was achieved on essential definition criteria and terminology, presented in 23 statements. The German term 'Sprachentwicklungsstörung' was endorsed to refer to children with significant deviations from typical language development that can negatively impact social interactions, educational progress, and/or social participation and do not occur together with a potentially contributing impairment. A significant deviation from typical language development was defined as a child's scores in standardized test procedures being ≥ 1.5 SD below the mean for children of the same age. The results of this Delphi study provide a proposal for a uniform use of terminology for language disorders in childhood in German-speaking countries