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1.
Applied Economics Letters ; : 1-12, 2022.
Article in English | Taylor & Francis | ID: covidwho-2062654
2.
Trends Analyt Chem ; 157: 116759, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1996594

ABSTRACT

COVID-19 has already been lasting for more than two years and it has been severely affecting the whole world. Still, detection of SARS-CoV-2 remains the frontline approach to combat the pandemic, and the reverse transcription polymerase chain reaction (RT-PCR)-based method is the well recognized detection method for the enormous analytical demands. However, the RT-PCR method typically takes a relatively long time, and can produce false positive and false negative results. Mass spectrometry (MS) is a very commonly used technique with extraordinary sensitivity, specificity and speed, and can produce qualitative and quantitative information of various analytes, which cannot be achieved by RT-PCR. Since the pandemic outbreak, various mass spectrometric approaches have been developed for rapid detection of SARS-CoV-2, including the LC-MS/MS approaches that could allow analysis of several hundred clinical samples per day with one MS system, MALDI-MS approaches that could directly analyze clinical samples for the detection, and efforts for the on-site detection with portable devices. In this review, these mass spectrometric approaches were summarized, and their pros and cons as well as further development were also discussed.

3.
Nat Commun ; 13(1): 3716, 2022 07 01.
Article in English | MEDLINE | ID: covidwho-1984382

ABSTRACT

The COVID-19 pandemic triggered the development of numerous diagnostic tools to monitor infection and to determine immune response. Although assays to measure binding antibodies against SARS-CoV-2 are widely available, more specific tests measuring neutralization activities of antibodies are immediately needed to quantify the extent and duration of protection that results from infection or vaccination. We previously developed a 'Serological Assay based on a Tri-part split-NanoLuc® (SATiN)' to detect antibodies that bind to the spike (S) protein of SARS-CoV-2. Here, we expand on our previous work and describe a reconfigured version of the SATiN assay, called Neutralization SATiN (Neu-SATiN), which measures neutralization activity of antibodies directly from convalescent or vaccinated sera. The results obtained with our assay and other neutralization assays are comparable but with significantly shorter preparation and run time for Neu-SATiN. As the assay is modular, we further demonstrate that Neu-SATiN enables rapid assessment of the effectiveness of vaccines and level of protection against existing SARS-CoV-2 variants of concern and can therefore be readily adapted for emerging variants.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , Humans , Luciferases , Membrane Glycoproteins/metabolism , Neutralization Tests , Pandemics , Spike Glycoprotein, Coronavirus , Viral Envelope Proteins
4.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-322027

ABSTRACT

To meet the urgent demand for better diagnostic tools to combat the ongoing COVID-19 pandemic, we developed a homogeneous immunoassay to detect IgG antibodies against SARS-CoV-2. This assay is based on a tri-part Nanoluciferase (tNLuc) approach, in which the spike protein of SARS-CoV-2 and protein G, fused respectively to two different tNLuc tags, are used as antibody probes. Target engagement of the probes allows reconstitution of a functional luciferase in the presence of the third tNLuc component. The assay is performed directly in liquid phase of patient sera and enables rapid, quantitative and low-cost detection. We show that tNLuc maintains a similar sensitivity to ELISA, while its readouts are highly consistent with various neutralizing antibody assays. This proof-of-principle study suggests potential applications in diagnostics and disease and vaccination management.

5.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296756

ABSTRACT

The COVID-19 pandemic triggered the development of numerous diagnostic tools to monitor infection and to determine immune response. Although assays to measure binding antibodies against SARS-CoV-2 are widely available, more specific tests measuring neutralization activities of antibodies are immediately needed to quantify the extent and duration of protection that results from infection or vaccination. We previously developed a ‘Serological Assay based on a Tri-part split-NanoLuc® (SATiN)’ to detect antibodies that bind to the spike (S) protein of SARS-CoV-2. Herein, we expand on our previous work and describe a reconfigured version of the SATiN assay that can measure neutralization activity of antibodies directly from convalescent or vaccinated sera. The sensitivity is comparable to cell-based pseudovirus neutralization assays but with significantly shorter preparation and assay run time. As the assay is modular, we further demonstrate that Neutralization SATiN (Neu-SATiN) enables rapid assessment of the effectiveness of vaccines and level of protection against existing SARS-CoV-2 variants of concern and can therefore be readily adapted for emerging variants.

6.
Current Issues in Tourism ; : 1-19, 2021.
Article in English | Taylor & Francis | ID: covidwho-1442944
7.
Int J Environ Res Public Health ; 18(7)2021 03 30.
Article in English | MEDLINE | ID: covidwho-1161042

ABSTRACT

Exploring spatio-temporal patterns of disease incidence can help to identify areas of significantly elevated or decreased risk, providing potential etiologic clues. The study uses the retrospective analysis of space-time scan statistic to detect the clusters of COVID-19 in mainland China with a different maximum clustering radius at the family-level based on case dates of onset. The results show that the detected clusters vary with the clustering radius. Forty-three space-time clusters were detected with a maximum clustering radius of 100 km and 88 clusters with a maximum clustering radius of 10 km from 2 December 2019 to 20 June 2020. Using a smaller clustering radius may identify finer clusters. Hubei has the most clusters regardless of scale. In addition, most of the clusters were generated in February. That indicates China's COVID-19 epidemic prevention and control strategy is effective, and they have successfully prevented the virus from spreading from Hubei to other provinces over time. Well-developed provinces or cities, which have larger populations and developed transportation networks, are more likely to generate space-time clusters. The analysis based on the data of cases from onset may detect the start times of clusters seven days earlier than similar research based on diagnosis dates. Our analysis of space-time clustering based on the data of cases on the family-level can be reproduced in other countries that are still seriously affected by the epidemic such as the USA, India, and Brazil, thus providing them with more precise signals of clustering.


Subject(s)
COVID-19 , Brazil , China/epidemiology , Cities , Cluster Analysis , Humans , India , Retrospective Studies , SARS-CoV-2 , Spatio-Temporal Analysis
8.
Nat Commun ; 12(1): 1806, 2021 03 22.
Article in English | MEDLINE | ID: covidwho-1146643

ABSTRACT

Better diagnostic tools are needed to combat the ongoing COVID-19 pandemic. Here, to meet this urgent demand, we report a homogeneous immunoassay to detect IgG antibodies against SARS-CoV-2. This serological assay, called SATiN, is based on a tri-part Nanoluciferase (tNLuc) approach, in which the spike protein of SARS-CoV-2 and protein G, fused respectively to two different tNLuc tags, are used as antibody probes. Target engagement of the probes allows reconstitution of a functional luciferase in the presence of the third tNLuc component. The assay is performed directly in the liquid phase of patient sera and enables rapid, quantitative and low-cost detection. We show that SATiN has a similar sensitivity to ELISA, and its readouts are consistent with various neutralizing antibody assays. This proof-of-principle study suggests potential applications in diagnostics, as well as disease and vaccination management.


Subject(s)
Antibodies, Viral/blood , COVID-19 Testing/methods , COVID-19/diagnosis , Immunoassay/methods , Luciferases/metabolism , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Antibodies, Neutralizing/blood , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/virology , Enzyme-Linked Immunosorbent Assay , HEK293 Cells , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Spike Glycoprotein, Coronavirus/immunology
9.
Inf Process Manag ; 58(4): 102583, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1135376

ABSTRACT

The sudden outbreak of coronavirus disease 2019 (COVID-19) in early 2020 has dramatically changed people's lives. Some countries have taken mass home quarantine to control the virus. However, the side effects of quarantine have rarely been interrogated by current COVID-19 research. This study thus investigates the effects of online social support on the public's beliefs in overcoming COVID-19 by embracing their cognition and emotion during the epidemic. First, by crawling and content analysis of the messages posted on "Baidu COVID-19 bar", this study identified 5 types of online social support given or received by the public during COVID-19. On this basis, a model explaining the public's beliefs was developed from the perspectives of online social support, cognition and emotion. 334 valid online questionnaires were collected to examine the proposed model and hypotheses. The results show that cognition has a direct effect on the belief, while emotion affects the belief via a full mediating effect of cognition. Tangible support and esteem support can directly affect the public's beliefs, and educational level significantly moderates these effects. In addition, the public's cognition is influenced by informational support, however, emotion is not influenced by social support but by other factors (e.g., information disclosure, material supplies and frustration caused by the epidemic). These research results provide a deep insight into how to reduce the negative effects of quarantine, consolidate the theoretical basis of the public's beliefs, and have important practical implications for individuals and the government in dealing with such emergencies.

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