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1.
Front Neurol ; 14: 1102335, 2023.
Article in English | MEDLINE | ID: covidwho-20244846

ABSTRACT

Background: Face masks are widely used in daily life because of the COVID-19 pandemic. The objective of this study was to explore the impact of wearing face masks on brain functions by using resting-state functional MRI (RS-fMRI). Methods: Scanning data from 15 healthy subjects (46.20 ± 6.67 years) were collected in this study. Each subject underwent RS-fMRI scans under two comparative conditions, wearing a KN95 mask and natural breathing (no mask). The amplitude of low frequency fluctuation (ALFF) and functional connectivity under the two conditions were analyzed and then compared using the paired t-test. Results: Compared with those of the no-mask condition, the ALFF activities when wearing masks were increased significantly in the right middle frontal gyrus, bilateral precuneus, right superior marginal gyrus, left inferior parietal gyrus, and left supplementary motor area and decreased significantly in the anterior cingulate gyrus, right fusiform gyrus, left superior temporal gyrus, bilateral lingual gyrus, and bilateral calcarine cortex (p < 0.05). Taking the posterior cingulate cortex area as a seed point, the correlations with the occipital cortex, prefrontal lobe, and motor sensory cortex were sensitive to wearing masks compared with not wearing masks (p < 0.05). Taking the medial prefrontal cortex region as a seed point, the functional connectivity with the bilateral temporal lobe, bilateral motor sensory cortex, and occipital lobe was influenced by wearing a KN95 mask (p < 0.05). Conclusion: This study demonstrated that wearing a KN95 face mask can cause short-term changes in human resting brain function. Both local neural activities and functional connectivity in brain regions were sensitive to mask wearing. However, the neural mechanism causing these changes and its impact on cognitive function still need further investigation.

2.
Sci Signal ; 16(783): eade1985, 2023 05 02.
Article in English | MEDLINE | ID: covidwho-2320556

ABSTRACT

Coronaviruses that can infect humans can cause either common colds (HCoV-NL63, HCoV-229E, HCoV-HKU1, and HCoV-OC43) or severe respiratory symptoms (SARS-CoV-2, SARS-CoV, and MERS-CoV). The papain-like proteases (PLPs) of SARS-CoV, SARS-CoV-2, MERS-CoV, and HCoV-NL63 function in viral innate immune evasion and have deubiquitinating (DUB) and deISGylating activities. We identified the PLPs of HCoV-229E, HCoV-HKU1, and HCoV-OC43 and found that their enzymatic properties correlated with their ability to suppress innate immune responses. A conserved noncatalytic aspartic acid residue was critical for both DUB and deISGylating activities, but the PLPs had differing ubiquitin (Ub) chain cleavage selectivities and binding affinities for Ub, K48-linked diUb, and interferon-stimulated gene 15 (ISG15) substrates. The crystal structure of HKU1-PLP2 in complex with Ub revealed binding interfaces that accounted for the unusually high binding affinity between this PLP and Ub. In cellular assays, the PLPs from the severe disease-causing coronaviruses strongly suppressed innate immune IFN-I and NF-κB signaling and stimulated autophagy, whereas the PLPs from the mild disease-causing coronaviruses generally showed weaker effects on immune suppression and autophagy induction. In addition, a PLP from a SARS-CoV-2 variant of concern showed increased suppression of innate immune signaling pathways. Overall, these results demonstrated that the DUB and deISGylating activities and substrate selectivities of these PLPs differentially contribute to viral innate immune evasion and may affect viral pathogenicity.


Subject(s)
COVID-19 , Papain , Humans , Papain/chemistry , Papain/genetics , Papain/metabolism , SARS-CoV-2/metabolism , Peptide Hydrolases/metabolism , Ubiquitin/metabolism , Immunity, Innate
3.
ACS Appl Mater Interfaces ; 2023 Mar 12.
Article in English | MEDLINE | ID: covidwho-2311701

ABSTRACT

Airborne particulate matter (PM) pollution has caused a public health threat, including nanoscale particles, especially with emerging infectious diseases and indoor and vehicular environmental pollution. However, most existing indoor air filtration units are expensive, energy-intensive, and bulky, and there is an unavoidable trade-off between low-efficiency PM0.3/pathogen interception, PM removal, and air resistance. Herein, we designed and synthesized a two-dimensional continuous cellulose-sheath/net with a unique dual-network corrugated architecture to manufacture high-efficiency air filters and even N95 particulate face mask. Combined with its sheath/net structured pores (size 100-200 nm) consisting of a cellulose framework (1-100 nm diameter), the cellulose sheath/net filter offers high-efficiency air filtration (>99.5338%, Extrafine particles; >99.9999%, PM2.5), low-pressure drops, and a robustness quality factor of >0.14 Pa-1, utilizing their ultralight weight of 30 mg/m2 and physical adhesion and sieving behaviors. Simultaneously, masks prepared with cellulose-sheath/net filters are more likely to capture and block smaller particles than the N95 standard. The synthesis of such materials with their nanoscale features and designed macrostructures may suggest new design criteria for a novel generation of high-efficiency air filter media for different applications such as personal protection products and industrial dust removal.

4.
Emerg Infect Dis ; 28(12): 2374-2382, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2311581

ABSTRACT

We investigated a cluster of SARS-CoV-2 infections in a quarantine hotel in Taiwan in December 2021. The cluster involved 3 case patients who lived in nonadjacent rooms on different floors. They had no direct contact during their stay. By direct exploration of the space above the room ceilings, we found residual tunnels, wall defects, and truncated pipes between their rooms. We conducted a simplified tracer-gas experiment to assess the interconnection between rooms. Aerosol transmission through structural defects in floors and walls in this poorly ventilated hotel was the most likely route of virus transmission. This event demonstrates the high transmissibility of Omicron variants, even across rooms and floors, through structural defects. Our findings emphasize the importance of ventilation and integrity of building structure in quarantine facilities.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Quarantine , Taiwan/epidemiology , Respiratory Aerosols and Droplets
5.
J Med Internet Res ; 25: e45051, 2023 04 14.
Article in English | MEDLINE | ID: covidwho-2305862

ABSTRACT

BACKGROUND: The COVID-19 vaccine is an effective tool in the fight against the COVID-19 outbreak. As the main channel of information dissemination in the context of the epidemic, social media influences public trust and acceptance of the vaccine. The rational application of health behavior theory is a guarantee of effective public health information dissemination. However, little is known about the application of health behavior theory in web-based COVID-19 vaccine messages, especially from Chinese social media posts. OBJECTIVE: This study aimed to understand the main topics and communication characteristics of hot papers related to COVID-19 vaccine on the WeChat platform and assess the health behavior theory application with the aid of health belief model (HBM). METHODS: A systematic search was conducted on the Chinese social media platform WeChat to identify COVID-19 vaccine-related papers. A coding scheme was established based on the HBM, and the sample was managed and coded using NVivo 12 (QSR International) to assess the application of health behavior theory. The main topics of the papers were extracted through the Latent Dirichlet Allocation algorithm. Finally, temporal analysis was used to explore trends in the evolution of themes and health belief structures in the papers. RESULTS: A total of 757 papers were analyzed. Almost all (671/757, 89%) of the papers did not have an original logo. By topic modeling, 5 topics were identified, which were vaccine development and effectiveness (267/757, 35%), disease infection and protection (197/757, 26%), vaccine safety and adverse reactions (52/757, 7%), vaccine access (136/757, 18%), and vaccination science popularization (105/757, 14%). All papers identified at least one structure in the extended HBM, but only 29 papers included all of the structures. Descriptions of solutions to obstacles (585/757, 77%) and benefit (468/757, 62%) were the most emphasized components in all samples. Relatively few elements of susceptibility (208/757, 27%) and the least were descriptions of severity (135/757, 18%). Heat map visualization revealed the change in health belief structure before and after vaccine entry into the market. CONCLUSIONS: To the best of our knowledge, this is the first study to assess the structural expression of health beliefs in information related to the COVID-19 vaccine on the WeChat public platform based on an HBM. The study also identified topics and communication characteristics before and after the market entry of vaccines. Our findings can inform customized education and communication strategies to promote vaccination not only in this pandemic but also in future pandemics.


Subject(s)
COVID-19 , Social Media , Humans , COVID-19/prevention & control , COVID-19 Vaccines/therapeutic use , Information Dissemination , Communication , Disease Outbreaks
6.
Clin Microbiol Infect ; 2023 Apr 20.
Article in English | MEDLINE | ID: covidwho-2295341

ABSTRACT

BACKGROUND: The effects of molnupiravir in treating patients with non-severe COVID-19 remain uncertain. OBJECTIVES: To evaluate the efficacy and safety of molnupiravir in adult patients with mild or moderate COVID-19. DATA SOURCES: PubMed, Embase, CENTRAL, Web of Science, and WHO COVID-19 database up to 27 December 2022. STUDY ELIGIBILITY CRITERIA: Randomized controlled trials with no language restrictions. PARTICIPANTS: Adults with mild or moderate COVID-19. INTERVENTIONS: Molnupiravir against standard care or placebo. ASSESSMENT OF RISK OF BIAS: We used a revision of RoB-2 criteria. METHODS OF DATA SYNTHESIS: Outcomes were mortality, hospital admission, viral clearance, time to viral clearance, time to symptom resolution or clinical improvement, any adverse events, and serious adverse events. We performed DerSimonian-Laird random-effects meta-analyses to summarize the evidence and evaluated the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. RESULTS: Nine randomized controlled trials enrolling 30 472 patients proved eligible. Majority of patients were outpatients, with a mean age ranging from 35 to 56.6 years. In adult patients with mild or moderate COVID-19, molnupiravir probably reduces mortality (relative risk [RR], 0.43; 95% CI, 0.20-0.94; risk difference [RD], 0.1% fewer; moderate certainty) and the risk of hospital admission (RR, 0.67; 95% CI, 0.45-0.99; RD, 1.4% fewer; moderate certainty) and may reduce time to viral clearance (mean difference, -1.81 days; 95% CI, -3.31 to -0.31; low certainty) and time to symptom resolution or clinical improvement (mean difference, -2.39 days; 95% CI, -3.71 to -1.07; low certainty). Molnupiravir probably increases the rate of viral clearance (RR, 3.47; 95% CI, 2.43-4.96; RD 16.1% more; moderate certainty) at 7 days (±3 days) and likely does not increase serious adverse events (RR, 0.84; 95% CI, 0.61-1.15; RD 0.1% fewer; moderate certainty). CONCLUSIONS: In adult patients with mild or moderate COVID-19, molnupiravir likely reduces mortality and risk of hospital admission probably without increasing serious adverse events.

7.
Sustainability ; 15(2), 2023.
Article in English | CAB Abstracts | ID: covidwho-2269342

ABSTRACT

Food supply chains (FSCs) have long been exposed to environmental variability and shock events caused by various economic, political, and infrastructural factors. The outbreak of the COVID-19 pandemic has further exposed and identified the vulnerability of FSCs, and promoted integrated optimization approaches for building resilience. However, existing works focusing on general supply chains (SCs) and FSCs have not been fully aware of the distinct characteristics of FSCs in green logistics, i.e., the expiration of fresh products. In reality, perishable food materials can be processed into products of different processing levels (i.e., multi-level processing) for longer shelf lives, which can serve as a timely and economic strategy to increase safety stocks for mitigating disruption risks. Motivated by this fact, we study the problem of enhancing FSC with a multi-level processing strategy. An integrated location, inventory, and distribution planning model for a multi-echelon FSC under COVID-19-related disruptions is formulated to maximize the total profit over a finite planning horizon. Specifically, a two-stage stochastic programming model is presented to hedge against disruption risks, where scenarios are generated to characterize geographical impact induced by source-region disruptions. For small-scale problems, the model can be solved with commercial solvers. To exactly and efficiently solve the large-scale instances, we design an integer L-shaped method. Numerical experiments are conducted on a case study and randomly generated instances to show the efficiency of our model and solution method. Based on the case study, managerial insights are drawn.

8.
Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi ; 2023.
Article in English | EuropePMC | ID: covidwho-2263481

ABSTRACT

Background Understanding the neutralizing antibody (NAb) titer against COVID-19 over time is important to provide information for vaccine implementation. The longitudinal NAb titer over one year after SARS-CoV-2 infection is still unclear. The purposes of this study are to evaluate the duration of the neutralizing NAb titers in COVID-19 convalescents and factors associated with the titer positive duration. Methods A cohort study followed COVID-19 individuals diagnosed between 2020 and 2021 May 15th from the COVID-19 database from the Taiwan Centers for Disease Control. We analyzed NAb titers from convalescent SARS-CoV-2 individuals. We used generalized estimating equations (GEE) and a Cox regression model to summarize the factors associated with NAb titers against COVID-19 decaying in the vaccine-free population. Results A total of 203 convalescent subjects with 297 analytic samples were followed for a period of up to 588 days. Our study suggests that convalescent COVID-19 in individuals after more than a year and four months pertains to only 25% of positive titers. The GEE model indicates that longer follow-up duration was associated with a significantly lower NAb titer. The Cox regression model indicated the disease severity with advanced condition was associated with maintaining NAb titers (adjusted hazard ratio: 2.08, 95% CI: 1.12–3.61) and that non-smoking also was associated with maintaining NAb titers (adjusted hazard ratio: 1.69, 95% CI: 1.08–2.64). Conclusions Neutralizing antibody titers diminished after more than a year. The antibody titer response against SARS-CoV-2 in naturally convalescent individuals provides a reference for vaccinations.

9.
SAGE Open Nurs ; 9: 23779608231158158, 2023.
Article in English | MEDLINE | ID: covidwho-2286247

ABSTRACT

Introduction: During the COVID-19 pandemic, the zero-tolerance policy implemented in Macao affected university students' life and learning styles. Objectives: This study aimed to investigate the prevalence of internet gaming disorder (IGD) and analyze its risk factors among university students of Macao amid the COVID-19 pandemic. Methods: Two hundred and twenty-nine university students were recruited by convenience sampling. The cross-sectional investigation was conducted using the 9-item Chinese version of the IGD Scale, the Chinese Version of the Self-Compassion Scale, and the Chinese version of the Brief Resilience Scale. Results: The prevalence was 7.4%. Compared to Non-IGD gamers, the IGD gamers were more likely to be the older, male gender, with a longer gaming history, with more game hours per day in the last month, and with a lower self-compassion score and resilience. Conclusion: The prevalence of IGD increased. Students who are the older, male gender, with more gaming time, low self-compassion, and low resilience, have a high possibility of IGD.

10.
J Microbiol Immunol Infect ; 56(3): 506-515, 2023 Jun.
Article in English | MEDLINE | ID: covidwho-2263484

ABSTRACT

BACKGROUND: Understanding the neutralizing antibody (NAb) titer against COVID-19 over time is important to provide information for vaccine implementation. The longitudinal NAb titer over one year after SARS-CoV-2 infection is still unclear. The purposes of this study are to evaluate the duration of the neutralizing NAb titers in COVID-19 convalescents and factors associated with the titer positive duration. METHODS: A cohort study followed COVID-19 individuals diagnosed between 2020 and 2021 May 15th from the COVID-19 database from the Taiwan Centers for Disease Control. We analyzed NAb titers from convalescent SARS-CoV-2 individuals. We used generalized estimating equations (GEE) and a Cox regression model to summarize the factors associated with NAb titers against COVID-19 decaying in the vaccine-free population. RESULTS: A total of 203 convalescent subjects with 297 analytic samples were followed for a period of up to 588 days. Our study suggests that convalescent COVID-19 in individuals after more than a year and four months pertains to only 25% of positive titers. The GEE model indicates that longer follow-up duration was associated with a significantly lower NAb titer. The Cox regression model indicated the disease severity with advanced condition was associated with maintaining NAb titers (adjusted hazard ratio: 2.01, 95% CI: 1.11-3.63) and that smoking was also associated with higher risk of negative NAb titers (adjusted hazard ratio: 0.55, 95% CI: 0.33-0.92). CONCLUSIONS: Neutralizing antibody titers diminished after more than a year. The antibody titer response against SARS-CoV-2 in naturally convalescent individuals provides a reference for vaccinations.


Subject(s)
COVID-19 , Humans , SARS-CoV-2 , Cohort Studies , Taiwan/epidemiology , Antibodies, Neutralizing , Antibodies, Viral
11.
Crit Rev Food Sci Nutr ; : 1-19, 2023 Feb 15.
Article in English | MEDLINE | ID: covidwho-2246451

ABSTRACT

INTRODUCTION: Micronutrients are clinically important in managing COVID-19, and numerous studies have been conducted, but inconsistent findings exist. OBJECTIVE: To explore the association between micronutrients and COVID-19. METHODS: PubMed, Web of Science, Embase, Cochrane Library and Scopus for study search on July 30, 2022 and October 15, 2022. Literature selection, data extraction and quality assessment were performed in a double-blinded, group discussion format. Meta-analysis with overlapping associations were reconsolidated using random effects models, and narrative evidence was performed in tabular presentations. RESULTS: 57 reviews and 57 latest original studies were included. 21 reviews and 53 original studies were of moderate to high quality. Vitamin D, vitamin B, zinc, selenium, and ferritin levels differed between patients and healthy people. Vitamin D and zinc deficiencies increased COVID-19 infection by 0.97-fold/0.39-fold and 1.53-fold. Vitamin D deficiency increased severity 0.86-fold, while low vitamin B and selenium levels reduced severity. Vitamin D and calcium deficiencies increased ICU admission by 1.09 and 4.09-fold. Vitamin D deficiency increased mechanical ventilation by 0.4-fold. Vitamin D, zinc, and calcium deficiencies increased COVID-19 mortality by 0.53-fold, 0.46-fold, and 5.99-fold, respectively. CONCLUSION: The associations between vitamin D, zinc, and calcium deficiencies and adverse evolution of COVID-19 were positive, while the association between vitamin C and COVID-19 was insignificant.REGISTRATION: PROSPERO CRD42022353953.

12.
Vaccines (Basel) ; 11(1)2022 Dec 21.
Article in English | MEDLINE | ID: covidwho-2228850

ABSTRACT

BACKGROUND: This study aimed to assess the safety and immunogenicity of MVC-COV1901, a recombinant COVID-19 protein vaccine, containing S-2P protein adjuvanted with CpG 1018 and aluminum hydroxide, for people living with HIV (PWH). METHODS: A total of 57 PWH of ≥20 years of age who are on stable antiretroviral therapy were compared with 882 HIV-negative participants. Participants received two doses of MVC-COV1901 28 days apart. RESULTS: No vaccine-related serious adverse events (SAEs) were recorded. Seroconversion rates (SCRs) of 100% and 99.8% were achieved in PWH and comparators, respectively, 28 days after the second dose. After adjusting for sex, age, BMI category, and comorbidity, the adjusted GMT ratio of comparator/PWH was 3.2 (95% CI 2.5-4). A higher CD4/CD8 ratio was associated with a higher GMT (R = 0.27, p = 0.039). MVC-COV1901 has shown robust safety but elicited weaker immune responses in PWH. CONCLUSIONS: Further investigations may be needed to determine whether PWH require distinct immunization strategies with improved immunogenicity. The main study is registered at ClinicalTrials.gov (NCT04695652).

13.
PLoS One ; 17(12): e0279500, 2022.
Article in English | MEDLINE | ID: covidwho-2197106

ABSTRACT

This study gives a corpus-assisted discourse study of the representations of the safety and efficacy of COVID-19 vaccines in three representative newspapers from the US, Hong Kong, and the Chinese mainland: New York Times (NYT), South China Morning Post (SCMP), and China Daily (CD). The primary purpose is to explicate the dynamics between vaccines, media, and politics. Combining the theories and methods of critical discourse analysis and corpus linguistics, this study has revealed their preferential ways of constructing the safety and efficacy of COVID-19 vaccines at different levels of discourse. The safety and efficacy of COVID-19 vaccines thus serve as an important ideological battlefield for newspapers from different origins to advance their respective national or regional interests and shape understanding of different COVID-19 vaccines in the international arena.


Subject(s)
COVID-19 Vaccines , COVID-19 , Humans , COVID-19/prevention & control , Politics , Hong Kong , China
14.
Oxid Med Cell Longev ; 2022: 1030238, 2022.
Article in English | MEDLINE | ID: covidwho-2194204

ABSTRACT

The effective remission of acute respiratory distress syndrome- (ARDS-) caused pulmonary fibrosis determines the recovery of lung function. Inositol can relieve lung injuries induced by ARDS. However, the mechanism of myo-inositol in the development of ARDS is unclear, which limits its use in the clinic. We explored the role and mechanism of myo-inositol in the development of ARDS by using an in vitro lipopolysaccharide- (LPS-) established alveolar epithelial cell inflammation model and an in vivo ARDS mouse model. Our results showed that inositol can alleviate the progression of pulmonary fibrosis. More significantly, we found that inositol can induce autophagy to inhibit the progression pulmonary fibrosis caused by ARDS. In order to explore the core regulators of ARDS affected by inositol, mRNA-seq sequencing was performed. Those results showed that transcription factor HIF-1α can regulate the expression of SLUG, which in turn can regulate the key gene E-Cadherin involved in cell epithelial-mesenchymal transition (EMT) as well as N-cadherin expression, and both were regulated by inositol. Our results suggest that inositol activates autophagy to inhibit EMT progression induced by the HIF-1α/SLUG signaling pathway in ARDS, and thereby alleviates pulmonary fibrosis.


Subject(s)
Pulmonary Fibrosis , Respiratory Distress Syndrome , Mice , Animals , Pulmonary Fibrosis/drug therapy , Pulmonary Fibrosis/chemically induced , Inositol/adverse effects , Signal Transduction , Respiratory Distress Syndrome/drug therapy , Cadherins/metabolism , Autophagy , Epithelial-Mesenchymal Transition , Lipopolysaccharides/pharmacology
15.
Sustainability ; 15(2):917, 2023.
Article in English | MDPI | ID: covidwho-2166897

ABSTRACT

Food supply chains (FSCs) have long been exposed to environmental variability and shock events caused by various economic, political, and infrastructural factors. The outbreak of the COVID-19 pandemic has further exposed and identified the vulnerability of FSCs, and promoted integrated optimization approaches for building resilience. However, existing works focusing on general supply chains (SCs) and FSCs have not been fully aware of the distinct characteristics of FSCs in green logistics, i.e., the expiration of fresh products. In reality, perishable food materials can be processed into products of different processing levels (i.e., multi-level processing) for longer shelf lives, which can serve as a timely and economic strategy to increase safety stocks for mitigating disruption risks. Motivated by this fact, we study the problem of enhancing FSC with a multi-level processing strategy. An integrated location, inventory, and distribution planning model for a multi-echelon FSC under COVID-19-related disruptions is formulated to maximize the total profit over a finite planning horizon. Specifically, a two-stage stochastic programming model is presented to hedge against disruption risks, where scenarios are generated to characterize geographical impact induced by source-region disruptions. For small-scale problems, the model can be solved with commercial solvers. To exactly and efficiently solve the large-scale instances, we design an integer L-shaped method. Numerical experiments are conducted on a case study and randomly generated instances to show the efficiency of our model and solution method. Based on the case study, managerial insights are drawn.

16.
Frontiers in psychology ; 13, 2022.
Article in English | EuropePMC | ID: covidwho-2126344

ABSTRACT

Objectives The purpose is to analyze existing studies related to the field of demoralization through bibliometrics. Methodology Relevant literature on demoralization was searched from PubMed, Web of Science, the Cochrane Library, and CINAHL Complete. Bibliometric analysis was performed using GraphPad Prisma 8.2.1, VOSviewer 1.6.18 and R software. Research publication trends, author-country collaboration, research hotspots and future trends were explored by generating network relationship maps. Results A total of 1,035 publications related to the field of demoralization were identified. The earliest relevant studies have been published since 1974, and the studies have grown faster since 2000. Psyche-oncology and Psychother Psychosom had the highest number of publications (n = 25). The United States, Italy and Australia have made outstanding contributions to the field and there was an active collaboration among leading scholars. Major research hotspots include the multiple ways of assessing demoralization, the specificity of various demographics and psychological disorders in different disease contexts, and the association and distinction of diverse clinical psychological abnormalities. The impact of COVID-19 on demoralization and subsequent interventions and psychological care may become a future research direction. Conclusion There has been a significant increase in research in the field of demoralization after 2000. The United States provided the most publications. There is overall active collaboration between authors, countries, and institutions. In future research, more attention will be paid to the effects of COVID-19 on demoralization and intervention care for this psychology.

17.
Nat Commun ; 13(1): 6866, 2022 Nov 11.
Article in English | MEDLINE | ID: covidwho-2119060

ABSTRACT

The effectiveness of a 3rd dose of SARS-CoV-2 vaccines waned quickly in the Omicron-predominant period. In response to fast-waning immunity and the threat of Omicron variant of concern (VOC) to healthcare workers (HCWs), we conduct a non-randomized trial (ChiCTR2200055564) in which 38 HCWs volunteer to receive a homologous booster of inactivated vaccines (BBIBP-CorV) 6 months after the 3rd dose. The primary and secondary outcomes are neutralizing antibodies (NAbs) and the receptor-binding domain (RBD)-directed antibodies, respectively. The 4th dose recalls waned immunity while having distinct effects on humoral responses to different antigens. The peak antibody response to the RBD induced by the 4th dose is inferior to that after the 3rd dose, whereas responses to the N-terminal domain (NTD) of spike protein are further strengthened significantly. Accordingly, the 4th dose further elevates the peak level of NAbs against ancestral SARS-CoV-2 and Omicron BA.2, but not BA.1 which has more NTD mutations. No severe adverse events related to vaccination are recorded during the trial. Here, we show that redistribution of immune focus after repeated vaccinations may modulate cross-protective immune responses against different VOCs.


Subject(s)
COVID-19 , Viral Vaccines , Humans , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines , Immunity, Humoral , Membrane Glycoproteins/genetics , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccines, Inactivated , Viral Envelope Proteins
18.
ACS Appl Mater Interfaces ; 14(45): 50534-50542, 2022 Nov 16.
Article in English | MEDLINE | ID: covidwho-2087120

ABSTRACT

The CRISPR-Cas system was developed into a molecular diagnostic tool with high sensitivity, low cost, and high specificity in recent years. Colorimetric assays based on nanozymes offer an attractive point-of-care testing method for their low cost of use and user-friendly operation. Here, a MnO2 nanozyme-mediated CRISPR-Cas12a system was instituted to detect SARS-CoV-2. MnO2 nanorods linked to magnetic beads via a single-stranded DNA (ssDNA) linker used as an oxidase-like nanozyme inducing the color change of 3,3',5,5'-tetramethylbenzidine, which can be distinguished by the naked eye. The detection buffer color will change when the Cas12a is activated by SARS-CoV-2 and indiscriminately cleave the linker ssDNA. The detection limit was 10 copies per microliter and showed no cross-reaction with other coronaviruses. The nanozyme-mediated CRISPR-Cas12a system shows high selectivity and facile operation, with great potential for molecular diagnosis in point-of-care testing applications.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , CRISPR-Cas Systems/genetics , Manganese Compounds , COVID-19/diagnosis , Nucleic Acid Amplification Techniques/methods , Oxides , DNA, Single-Stranded
19.
BMJ Glob Health ; 7(10)2022 10.
Article in English | MEDLINE | ID: covidwho-2064138

ABSTRACT

INTRODUCTION: In recent years, the concept of living systematic review (LSR) has attracted the attention of many scholars and institutions. A growing number of studies have been conducted based on LSR methodology, but their focus direction is unclear. The objective of this study was to provide a comprehensive review of existing LSR-related studies and to analyse their whole picture and future trends with bibliometrics. METHODS: A comprehensive search strategy was used to construct a representative dataset of LSRs up to October 2021. GraphPad V.8.2.1 and Mindmaster Pro presented the basic information of the included studies and the timeline of LSR development, respectively. The author and country cooperation network, hotspot distribution clustering, historical citation network and future development trend prediction related to LSR were visualised by VOSviewer V.1.6.16 and R-Studio V.1.4. RESULTS: A total of 213 studies were eventually included. The concept of LSR was first proposed in 2014, and the number of studies has proliferated since 2020. There was a closer collaboration between author teams and more frequent LSR research development and collaboration in Europe, North America and Australia. Numerous LSR studies have been published in high-impact journals. COVID-19 is the predominant disease of concern at this stage, and the rehabilitation of its patients and virological studies are possible directions of research in LSR for a long time to come. A review of existing studies found that more than half of the LSR series had not yet been updated and that the method needed to be more standardised in practice. CONCLUSION: Although LSR has a relatively short history, it has received much attention and currently has a high overall acceptance. The LSR methodology was further practised in COVID-19, and we look forward to seeing it applied in more areas.


Subject(s)
COVID-19 , Bibliometrics , Europe , Humans , North America , Research Design
20.
Transbound Emerg Dis ; 69(5): e2122-e2131, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-2053007

ABSTRACT

The ongoing enzootic circulation of the Middle East respiratory syndrome coronavirus (MERS-CoV) in the Middle East and North Africa is increasingly raising the concern about the possibility of its recombination with other human-adapted coronaviruses, particularly the pandemic SARS-CoV-2. We aim to provide an updated picture about ecological niches of MERS-CoV and associated socio-environmental drivers. Based on 356 confirmed MERS cases with animal contact reported to the WHO and 63 records of animal infections collected from the literature as of 30 May 2020, we assessed ecological niches of MERS-CoV using an ensemble model integrating three machine learning algorithms. With a high predictive accuracy (area under receiver operating characteristic curve = 91.66% in test data), the ensemble model estimated that ecologically suitable areas span over the Middle East, South Asia and the whole North Africa, much wider than the range of reported locally infected MERS cases and test-positive animal samples. Ecological suitability for MERS-CoV was significantly associated with high levels of bareland coverage (relative contribution = 30.06%), population density (7.28%), average temperature (6.48%) and camel density (6.20%). Future surveillance and intervention programs should target the high-risk populations and regions informed by updated quantitative analyses.


Subject(s)
COVID-19 , Middle East Respiratory Syndrome Coronavirus , Animals , COVID-19/epidemiology , COVID-19/veterinary , Camelus , Humans , Machine Learning , SARS-CoV-2
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