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1.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-319369

ABSTRACT

Background: Population-based studies investigating the dynamics of the SARS-CoV-2 pandemic are needed. Here, we report on baseline findings from April through June 2020 of a prospective cohort study in Munich, Germany.Methods: We drew a representative sample of 2994 private households. The 5313 participating household members 14 years and older completed questionnaires and provided blood samples. SARS-CoV-2 seropositivity was defined as Roche N pan-Ig ≥ 0·4218. We adjusted the prevalence for the sampling design, sensitivity, and specificity. We investigated risk factors for SARS-CoV-2 seropositivity and geospatial transmission patterns by generalized linear mixed models and permutation tests.Findings: Seropositivity for SARS-CoV-2 specific antibodies was 1·82% (95% confidence interval (CI) 1·28-2·37%) as compared to 0·46% PCR-positive cases officially registered in Munich. Loss of the sense of smell or taste was associated with seropositivity (odds ratio (OR) 47·4;95% CI 7·2-307·0) and infections clustered within households. Participants suffering from respiratory allergies (OR 2·7;95% CI 0·9-8·6) and working in high-risk jobs (OR 2·0;95% CI 0·5-6·7) showed non-significantly increased odds for SARS-CoV-2 seropositivity.Interpretation: Applying a validated assay, we demonstrate a low SARS-CoV-2 seroprevalence in the Munich population 14 years and older towards the end of the first pandemic wave. However, we noted official sub-registration at this early stage of the pandemic.Funding: Bavarian State Ministry of Science and the Arts, University Hospital of LMU Munich, Helmholtz Centre Munich, University of Bonn, and University of Bielefeld.Declaration of Interests: FF, TF, DM, LO, and VT report grants from the Bavarian State Ministry of Science and the Arts during the conduct oft he study. TF reports grants from the University Hospital of LMU Munich, Helmholtz Center Munich, University of Bonn, University of Bielefeld, and German Ministry for Education and Research during the conduct of the study. JH reports grants from the German Federal Ministry of Education and Research during the conduct of the study. MH and AW report personal fees and non-financial support, LO and MP report non-financial support from Roche Diagnostics. MH, LO, MP, and AW report non-financial support from Euroimmun, Viramed, and Mikrogen. MH, MP, and AW report grants, non-financial support, and other from German Center for Infection Research (DZIF). FF, MH, LO, MP, VT, and AW report grants and non-financial support from the Government of Bavaria. MH, LO, MP, and AW report non-financial support from BMW, Mercedes Benz, Munich Police, and Accenture. MH and AW report personal fees and non-financial support from Dr. Box Betrobox during the conduct of the study. LO and MP report non-financial support from Dr. Box Betrobox. MH and AW have a patent Sample System for Sputum Diagnostics of SARS-CoV-2 pending. DM reports to be a a sub-investigator on a Phase I SARS-CoV-2 vaccine trial and on a Phase I rabies vaccine trial, both sponsored by CureVac AG. MP and AW report non-financial support from Dr. Becker MVZ. VT reports support from CureVac AG outside the submitted work. AW reports personal fees and other from Haeraeus Sensors. AW reports non-financial support from Bruker Daltronics outside the submitted work. AW is involved in other different patents and companies not in relation with the serology of SARS-CoV-2. All other authors report nothing to disclose.Ethics Approval Statement: Prior to study initiation, this study had been approved by therespective Institutional Review Board.

2.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-294509

ABSTRACT

Mathematical models have been widely used during the ongoing SARS-CoV-2 pandemic for data interpretation, forecasting, and policy making. However, most models are based on officially reported case numbers, which depend on test availability and test strategies. The time dependence of these factors renders interpretation difficult and might even result in estimation biases. Here, we present a computational modelling framework that allows for the integration of reported case numbers with seroprevalence estimates obtained from representative population cohorts. To account for the time dependence of infection and testing rates, we embed flexible splines in an epidemiological model. The parameters of these splines are estimated, along with the other parameters, from the available data using a Bayesian approach. The application of this approach to the official case numbers reported for Munich (Germany) and the seroprevalence reported by the prospective COVID-19 Cohort Munich (KoCo19) provides first estimates for the time dependence of the under-reporting factor. Furthermore, we estimate how the effectiveness of non-pharmaceutical interventions and of the testing strategy evolves over time. Overall, our results show that the integration of temporally highly resolved and representative data is beneficial for accurate epidemiological analyses.

3.
J Gen Virol ; 102(10)2021 10.
Article in English | MEDLINE | ID: covidwho-1488154

ABSTRACT

A number of seroassays are available for SARS-CoV-2 testing; yet, head-to-head evaluations of different testing principles are limited, especially using raw values rather than categorical data. In addition, identifying correlates of protection is of utmost importance, and comparisons of available testing systems with functional assays, such as direct viral neutralisation, are needed.We analysed 6658 samples consisting of true-positives (n=193), true-negatives (n=1091), and specimens of unknown status (n=5374). For primary testing, we used Euroimmun-Anti-SARS-CoV-2-ELISA-IgA/IgG and Roche-Elecsys-Anti-SARS-CoV-2. Subsequently virus-neutralisation, GeneScriptcPass, VIRAMED-SARS-CoV-2-ViraChip, and Mikrogen-recomLine-SARS-CoV-2-IgG were applied for confirmatory testing. Statistical modelling generated optimised assay cut-off thresholds. Sensitivity of Euroimmun-anti-S1-IgA was 64.8%, specificity 93.3% (manufacturer's cut-off); for Euroimmun-anti-S1-IgG, sensitivity was 77.2/79.8% (manufacturer's/optimised cut-offs), specificity 98.0/97.8%; Roche-anti-N sensitivity was 85.5/88.6%, specificity 99.8/99.7%. In true-positives, mean and median Euroimmun-anti-S1-IgA and -IgG titres decreased 30/90 days after RT-PCR-positivity, Roche-anti-N titres decreased significantly later. Virus-neutralisation was 80.6% sensitive, 100.0% specific (≥1:5 dilution). Neutralisation surrogate tests (GeneScriptcPass, Mikrogen-recomLine-RBD) were >94.9% sensitive and >98.1% specific. Optimised cut-offs improved test performances of several tests. Confirmatory testing with virus-neutralisation might be complemented with GeneScriptcPassTM or recomLine-RBD for certain applications. Head-to-head comparisons given here aim to contribute to the refinement of testing strategies for individual and public health use.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19/diagnosis , Neutralization Tests/methods , SARS-CoV-2/immunology , COVID-19 Nucleic Acid Testing , Cohort Studies , Humans
4.
BMC Infect Dis ; 21(1): 925, 2021 Sep 08.
Article in English | MEDLINE | ID: covidwho-1398842

ABSTRACT

BACKGROUND: In the 2nd year of the COVID-19 pandemic, knowledge about the dynamics of the infection in the general population is still limited. Such information is essential for health planners, as many of those infected show no or only mild symptoms and thus, escape the surveillance system. We therefore aimed to describe the course of the pandemic in the Munich general population living in private households from April 2020 to January 2021. METHODS: The KoCo19 baseline study took place from April to June 2020 including 5313 participants (age 14 years and above). From November 2020 to January 2021, we could again measure SARS-CoV-2 antibody status in 4433 of the baseline participants (response 83%). Participants were offered a self-sampling kit to take a capillary blood sample (dry blood spot; DBS). Blood was analysed using the Elecsys® Anti-SARS-CoV-2 assay (Roche). Questionnaire information on socio-demographics and potential risk factors assessed at baseline was available for all participants. In addition, follow-up information on health-risk taking behaviour and number of personal contacts outside the household (N = 2768) as well as leisure time activities (N = 1263) were collected in summer 2020. RESULTS: Weighted and adjusted (for specificity and sensitivity) SARS-CoV-2 sero-prevalence at follow-up was 3.6% (95% CI 2.9-4.3%) as compared to 1.8% (95% CI 1.3-3.4%) at baseline. 91% of those tested positive at baseline were also antibody-positive at follow-up. While sero-prevalence increased from early November 2020 to January 2021, no indication of geospatial clustering across the city of Munich was found, although cases clustered within households. Taking baseline result and time to follow-up into account, men and participants in the age group 20-34 years were at the highest risk of sero-positivity. In the sensitivity analyses, differences in health-risk taking behaviour, number of personal contacts and leisure time activities partly explained these differences. CONCLUSION: The number of citizens in Munich with SARS-CoV-2 antibodies was still below 5% during the 2nd wave of the pandemic. Antibodies remained present in the majority of SARS-CoV-2 sero-positive baseline participants. Besides age and sex, potentially confounded by differences in behaviour, no major risk factors could be identified. Non-pharmaceutical public health measures are thus still important.


Subject(s)
COVID-19 , Pandemics , Follow-Up Studies , Germany/epidemiology , Humans , Infant, Newborn , Male , SARS-CoV-2
5.
Front Immunol ; 12: 688436, 2021.
Article in English | MEDLINE | ID: covidwho-1259348

ABSTRACT

Background: Adaptive immune responses to structural proteins of the virion play a crucial role in protection against coronavirus disease 2019 (COVID-19). We therefore studied T cell responses against multiple SARS-CoV-2 structural proteins in a large cohort using a simple, fast, and high-throughput approach. Methods: An automated interferon gamma release assay (IGRA) for the Nucleocapsid (NC)-, Membrane (M)-, Spike-C-terminus (SCT)-, and N-terminus-protein (SNT)-specific T cell responses was performed using fresh whole blood from study subjects with convalescent, confirmed COVID-19 (n = 177, more than 200 days post infection), exposed household members (n = 145), and unexposed controls (n = 85). SARS-CoV-2-specific antibodies were assessed using Elecsys® Anti-SARS-CoV-2 (Ro-N-Ig) and Anti-SARS-CoV-2-ELISA (IgG) (EI-S1-IgG). Results: 156 of 177 (88%) previously PCR confirmed cases were still positive by Ro-N-Ig more than 200 days after infection. In T cells, most frequently the M-protein was targeted by 88% seropositive, PCR confirmed cases, followed by SCT (85%), NC (82%), and SNT (73%), whereas each of these antigens was recognized by less than 14% of non-exposed control subjects. Broad targeting of these structural virion proteins was characteristic of convalescent SARS-CoV-2 infection; 68% of all seropositive individuals targeted all four tested antigens. Indeed, anti-NC antibody titer correlated loosely, but significantly with the magnitude and breadth of the SARS-CoV-2-specific T cell response. Age, sex, and body mass index were comparable between the different groups. Conclusion: SARS-CoV-2 seropositivity correlates with broad T cell reactivity of the structural virus proteins at 200 days after infection and beyond. The SARS-CoV-2-IGRA can facilitate large scale determination of SARS-CoV-2-specific T cell responses with high accuracy against multiple targets.


Subject(s)
COVID-19/immunology , Interferon-gamma/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Viral Structural Proteins/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Viral/blood , COVID-19/blood , Female , Humans , Interferon-gamma Release Tests , Male , Middle Aged , Young Adult
6.
Int J Environ Res Public Health ; 18(7)2021 03 30.
Article in English | MEDLINE | ID: covidwho-1160500

ABSTRACT

Given the large number of mild or asymptomatic SARS-CoV-2 cases, only population-based studies can provide reliable estimates of the magnitude of the pandemic. We therefore aimed to assess the sero-prevalence of SARS-CoV-2 in the Munich general population after the first wave of the pandemic. For this purpose, we drew a representative sample of 2994 private households and invited household members 14 years and older to complete questionnaires and to provide blood samples. SARS-CoV-2 seropositivity was defined as Roche N pan-Ig ≥ 0.4218. We adjusted the prevalence for the sampling design, sensitivity, and specificity. We investigated risk factors for SARS-CoV-2 seropositivity and geospatial transmission patterns by generalized linear mixed models and permutation tests. Seropositivity for SARS-CoV-2-specific antibodies was 1.82% (95% confidence interval (CI) 1.28-2.37%) as compared to 0.46% PCR-positive cases officially registered in Munich. Loss of the sense of smell or taste was associated with seropositivity (odds ratio (OR) 47.4; 95% CI 7.2-307.0) and infections clustered within households. By this first population-based study on SARS-CoV-2 prevalence in a large German municipality not affected by a superspreading event, we could show that at least one in four cases in private households was reported and known to the health authorities. These results will help authorities to estimate the true burden of disease in the population and to take evidence-based decisions on public health measures.


Subject(s)
COVID-19 , Coronavirus Infections , Humans , Prevalence , Risk Factors , SARS-CoV-2
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