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2.
biorxiv; 2024.
Preprint Dans Anglais | bioRxiv | ID: ppzbmed-10.1101.2024.03.03.583237

Résumé

Coronaviruses display versatile receptor usage, yet in-depth characterization of coronaviruses lacking known receptor identities has been impeded by the absence of feasible infection models. Here, we developed an innovative strategy to engineer functional customized viral receptors (CVRs). The modular design relies on building receptor frameworks comprising various function modules and generating specific epitope-targeting viral binding domains. We showed the key factors for CVRs to efficiently facilitate spike cleavage, membrane fusion, pseudovirus entry, and authentic virus amplification for various coronaviruses, resembling their native receptors. Applying this strategy, we delineated the accessible receptor binding epitopes for functional SARS-CoV-2 CVR design and elucidated the mechanism of entry supported by an amino-terminus domain (NTD) targeting S2L20-CVR. Furthermore, we created CVR-expressing cells for assessing antibodies and inhibitors against 12 representative coronaviruses from six subgenera, most of which lacking known receptors. Notably, a pan-sarbecovirus CVR supported entry of various sarbecoviruses, as well as amplification of a replicable HKU3 pseudovirus and the authentic strain RsHuB2019A. Through combining an HKU5-specific CVR with reverse genetics, we successfully rescued and cultured wild-type and fluorescence protein-incorporated HKU5, a receptor-unidentified merbecovirus. Our study demonstrated the great potential of CVR strategy in establishing native receptor-independent infection models, paving the way for studying various viruses that are challenging to culture due to the lack of susceptible cells.

3.
researchsquare; 2024.
Preprint Dans Anglais | PREPRINT-RESEARCHSQUARE | ID: ppzbmed-10.21203.rs.3.rs-4011023.v1

Résumé

Coronaviruses display versatile receptor usage, yet in-depth characterization of coronaviruses lacking known receptor identities has been impeded by the absence of feasible infection models1,2. Here, we developed an innovative strategy to engineer functional customized viral receptors (CVRs). The modular design relies on building receptor frameworks comprising various function modules and generating specific epitope-targeting viral binding domains. We showed the key factors for CVRs to efficiently facilitate spike cleavage, membrane fusion, pseudovirus entry, and authentic virus propagation for various coronaviruses, resembling their native receptors. Applying this strategy, we delineated the accessible receptor binding epitopes for functional SARS-CoV-2 CVR design and elucidated the mechanism of entry supported by an amino-terminus domain (NTD) targeting S2L20-CVR. Furthermore, we created CVR-expressing cells for assessing antibodies and inhibitors against 12 representative coronaviruses from six subgenera, most of which lacking known receptors. Notably, a pan-sarbecovirus CVR supported entry of various sarbecoviruses, as well as propagation of a replicable HKU3 pseudovirus and the authentic strain RsHuB2019A3. Through combining an HKU5-specific CVR with reverse genetics, we successfully rescued and cultured wild-type and fluorescence protein-incorporated HKU5, a receptor-unidentified merbecovirus. Our study demonstrated the great potential of CVR strategy in establishing native receptor-independent infection models, paving the way for studying various viruses that are challenging to culture due to the lack of susceptible cells.

4.
researchsquare; 2024.
Preprint Dans Anglais | PREPRINT-RESEARCHSQUARE | ID: ppzbmed-10.21203.rs.3.rs-3880692.v1

Résumé

While clinical instances of cytotoxic lesions of the corpus callosum (CLOCCs) are well-documented, international reports specific to COVID-19-related cases remain limited. This paper presents the case of a 40-year-old female patient admitted due to "sudden dizziness and poor limb coordination for 7 weeks following fever." She tested positive for COVID-19 and experienced symptoms like dizziness, temporary confusion, nausea, vomiting, cerebellar speech issues, and ataxia after fever onset. Later, she developed pyramidal tract symptoms and behavioral abnormalities. Head MRI revealed abnormal high signal in the splenium of the corpus callosum and abnormal signals in the left cerebellar peduncle on DWI. With no significant medical history and exclusion of other causes during treatment (including steroid therapy and two doses of intravenous immunoglobulin), a follow-up MRI after one month showed the lesions had disappeared. However, clinical recovery was slow, with residual symptoms persisting for almost a year, including involuntary tremors in the upper limbs and head. Phenytoin, gabapentin, and pregabalin showed limited effectiveness in treatment, but Arotinolol and donepezil led to slight improvement in involuntary tremors. This case suggests that COVID-19-associated CLOCCs might have a protracted course and severe symptoms, demanding differentiation from ischemic cerebrovascular diseases, particularly in early stages.


Sujets)
Fièvre , Nausée , Troubles mentaux , Sensation vertigineuse , Lésions traumatiques cérébrovasculaires , Tremblement , Effets secondaires indésirables des médicaments , Vomissement , COVID-19 , Ataxie , Confusion
5.
arxiv; 2023.
Preprint Dans Anglais | PREPRINT-ARXIV | ID: ppzbmed-2311.01372v2

Résumé

With the increasing pursuit of objective reports, automatically understanding media bias has drawn more attention in recent research. However, most of the previous work examines media bias from Western ideology, such as the left and right in the political spectrum, which is not applicable to Chinese outlets. Based on the previous lexical bias and informational bias structure, we refine it from the Chinese perspective and go one step further to craft data with 7 fine-grained labels. To be specific, we first construct a dataset with Chinese news reports about COVID-19 which is annotated by our newly designed system, and then conduct substantial experiments on it to detect media bias. However, the scale of the annotated data is not enough for the latest deep-learning technology, and the cost of human annotation in media bias, which needs a lot of professional knowledge, is too expensive. Thus, we explore some context enrichment methods to automatically improve these problems. In Data-Augmented Context Enrichment (DACE), we enlarge the training data; while in Retrieval-Augmented Context Enrichment (RACE), we improve information retrieval methods to select valuable information and integrate it into our models to better understand bias. Extensive experiments are conducted on both our dataset and an English dataset BASIL. Our results show that both methods outperform our baselines, while the RACE methods are more efficient and have more potential.


Sujets)
COVID-19
8.
Inventions ; 8(2):63, 2023.
Article Dans Anglais | ProQuest Central | ID: covidwho-2305626

Résumé

The popularity of the online teaching model increased during the COVID-19, and virtual reality online education is now firmly established as a future trend in educational growth. Human–computer interaction and collaboration between virtual models and physical entities, as well as virtual multi-sensory cognition, have become the focus of research in the field of online education. In this paper, we analyze the mapping form of teaching information and cue information on users' cognition through an experimental system and investigate the effects of the presentation form of online virtual teaching information, the length of the material, users' memory of the information, and the presentation form of information cues on users' cognitive performance. The experimental results show that different instructional information and cue presentation designs have significant effects on users' learning performance, with relatively longer instructional content being more effective and users being more likely to mechanically remember the learning materials. By studying the impact of multi-sensory information presentation on users' cognition, the output design of instructional information can be optimized, cognitive resources can be reasonably allocated, and learning effectiveness can be ensured, which is of great significance for virtual education research in digital twins.

9.
Sci China Life Sci ; 2023 Apr 14.
Article Dans Anglais | MEDLINE | ID: covidwho-2297189

Résumé

Protein-biomolecule interactions play pivotal roles in almost all biological processes. For a biomolecule of interest, the identification of the interacting protein(s) is essential. For this need, although many assays are available, highly robust and reliable methods are always desired. By combining a substrate-based proximity labeling activity from the pupylation pathway of Mycobacterium tuberculosis and the streptavidin (SA)-biotin system, we developed the Specific Pupylation as IDEntity Reporter (SPIDER) method for identifying protein-biomolecule interactions. Using SPIDER, we validated the interactions between the known binding proteins of protein, DNA, RNA, and small molecule. We successfully applied SPIDER to construct the global protein interactome for m6A and mRNA, identified a variety of uncharacterized m6A binding proteins, and validated SRSF7 as a potential m6A reader. We globally identified the binding proteins for lenalidomide and CobB. Moreover, we identified SARS-CoV-2-specific receptors on the cell membrane. Overall, SPIDER is powerful and highly accessible for the study of protein-biomolecule interactions.

10.
Journal of infection and public health ; 2023.
Article Dans Anglais | EuropePMC | ID: covidwho-2288881

Résumé

Background Millions of COVID-19 pediatric survivors are facing the risk of long COVID after recovery from acute COVID-19. The primary objective of this study was to systematically review the available literature and determine the pooled prevalence of, and risk factors for long COVID among the pediatric survivors. Methods Studies that assessed the prevalence of, or risk factors associated with long COVID among pediatric COVID-19 survivors were systematically searched in PubMed, Embase, Cochrane Library, medRxiv and bioRxiv up to December 11th, 2022. Random effects model was performed to estimate the pooled prevalence of long COVID among pediatric COVID-19 patients. Subgroup analyses and meta-regression on the estimated prevalence of long COVID were performed by stratification with follow-up duration, mean age, sex ratio, percentage of multisystem inflammatory syndrome, hospitalization rate at baseline, and percentage of severe illness. Results Based on 40 studies with 12,424 individuals, the pooled prevalence of any long COVID was 23.36% ([95% CI 15.27-32.53]). The generalized symptom (19.57%, [95% CI 9.85-31.52]) was reported most commonly, followed by respiratory (14.76%, [95% CI 7.22-24.27]), neurologic (13.51%, [95% CI 6.52-22.40]), and psychiatric (12.30%, [95% CI 5.38-21.37]). Dyspnoea (22.75%, [95% CI 9.38-39.54]), fatigue (20.22%, [95% CI 9.19-34.09]), and headache (15.88%, [95% CI 6.85-27.57]) were most widely reported specific symptoms. The prevalence of any symptom during 3-6, 6-12, and >12 months were 26.41% ([95% CI 14.33-40.59]), 20.64% ([95% CI 17.06-24.46]), and 14.89% ([95% CI 6.09-26.51]), respectively. Individuals with aged over ten years, multisystem inflammatory syndrome, or had severe clinical symptoms exhibited higher prevalence of long COVID in multi-systems. Factors such as older age, female, poor physical or mental health, or had severe infection or more symptoms were more likely to have long COVID in pediatric survivors. Conclusions Nearly one quarter of pediatric survivors suffered multisystem long COVID, even at 1 year after infection. Ongoing monitoring, comprehensive prevention and intervention is warranted for pediatric survivors, especially for individuals with high risk factors.

11.
J Infect Public Health ; 16(5): 660-672, 2023 May.
Article Dans Anglais | MEDLINE | ID: covidwho-2288882

Résumé

BACKGROUND: Millions of COVID-19 pediatric survivors are facing the risk of long COVID after recovery from acute COVID-19. The primary objective of this study was to systematically review the available literature and determine the pooled prevalence of, and risk factors for long COVID among the pediatric survivors. METHODS: Studies that assessed the prevalence of, or risk factors associated with long COVID among pediatric COVID-19 survivors were systematically searched in PubMed, Embase, and Cochrane Library up to December 11th, 2022. Random effects model was performed to estimate the pooled prevalence of long COVID among pediatric COVID-19 patients. Subgroup analyses and meta-regression on the estimated prevalence of long COVID were performed by stratification with follow-up duration, mean age, sex ratio, percentage of multisystem inflammatory syndrome, hospitalization rate at baseline, and percentage of severe illness. RESULTS: Based on 40 studies with 12,424 individuals, the pooled prevalence of any long COVID was 23.36 % ([95 % CI 15.27-32.53]). The generalized symptom (19.57 %, [95 % CI 9.85-31.52]) was reported most commonly, followed by respiratory (14.76 %, [95 % CI 7.22-24.27]), neurologic (13.51 %, [95 % CI 6.52-22.40]), and psychiatric (12.30 %, [95% CI 5.38-21.37]). Dyspnea (22.75 %, [95% CI 9.38-39.54]), fatigue (20.22 %, [95% CI 9.19-34.09]), and headache (15.88 %, [95 % CI 6.85-27.57]) were most widely reported specific symptoms. The prevalence of any symptom during 3-6, 6-12, and> 12 months were 26.41 % ([95 % CI 14.33-40.59]), 20.64 % ([95 % CI 17.06-24.46]), and 14.89 % ([95 % CI 6.09-26.51]), respectively. Individuals with aged over ten years, multisystem inflammatory syndrome, or had severe clinical symptoms exhibited higher prevalence of long COVID in multi-systems. Factors such as older age, female, poor physical or mental health, or had severe infection or more symptoms were more likely to have long COVID in pediatric survivors. CONCLUSIONS: Nearly one quarter of pediatric survivors suffered multisystem long COVID, even at 1 year after infection. Ongoing monitoring, comprehensive prevention and intervention is warranted for pediatric survivors, especially for individuals with high risk factors.


Sujets)
COVID-19 , Adolescent , Sujet âgé , Enfant , Femelle , Humains , COVID-19/épidémiologie , , Prévalence , Facteurs de risque
12.
Heliyon ; 9(4): e15051, 2023 Apr.
Article Dans Anglais | MEDLINE | ID: covidwho-2287890

Résumé

Background: Although current studies have identified sleep disorders as an independent risk factor for suicide, the relationship between sleep disorders and suicide risk has not been well established. This study explored whether anxiety and depressive symptoms are used as mediators to participate in the impact of sleep quality on suicide risk. Methods: This is a cross-sectional study. We administered a psychological questionnaire to the participants, using a combination of self-assessment and psychiatrist assessment.Sleep quality, suicide risk, level of anxiety and depressive symptoms were assessed by PSQI, NGASR, SAS and SDS.The study subjects were 391 hospitalized COVID-19 patients from Wuhan hospitals. We used model 6 in the PROCESS (version 3.5) plug-in of SPSS software to conduct mediation test with sleep quality as the independent variable, suicide risk as the dependent variable, level of anxiety and depressive symptoms as intermediate variables. Results: The severity of anxiety and depressive symptoms and the risk of suicide in the sleep disorder group (63.15 ± 13.71, 59.85 ± 13.38, 6.52 ± 3.67) were higher than those in the non-sleep disorder group (49.83 ± 13.14, 44.87 ± 10.19, 2.87 ± 3.26) (P < 0.001). The mediation model works well, The total indirect effect was 0.22 (95%CI = [0.17, 0.28]), and the direct effect was 0.16 (95%CI = [0.08, 0.24]). Limitations: This study used a self-assessment scale. Conclusions: Anxiety and depressive symptoms played a chain mediating role between sleep quality and suicide risk.

13.
biorxiv; 2023.
Preprint Dans Anglais | bioRxiv | ID: ppzbmed-10.1101.2023.03.24.534062

Résumé

Background: Our understanding of SARS-CoV-2 evolution and mutation rate is limited. The rate of SARS-CoV-2 evolution is minimized through a proofreading function encoded by NSP-14 and may be affected by patient comorbidity. Current understanding of SARS-CoV-2 mutational rate is through population based analysis while intra-host mutation rate remains poorly studied. Methods: Viral genome analysis was performed between paired samples and mutations quantified at allele frequencies (AF) [≥]0.25, [≥]0.5 and [≥]0.75. Mutation rate was determined employing F81 and JC69 evolution models and compared between isolates with ({Delta}NSP-14) and without (wtNSP-14) non-synonymous mutations in NSP-14 and by patient comorbidity. Results: Forty paired samples with median interval of 13 days [IQR 8.5-20] were analyzed. The estimated mutation rate by F81 modeling was 93.6 (95%CI:90.8-96.4], 40.7 (95%CI:38.9-42.6) and 34.7 (95%CI:33.0-36.4) substitutions/genome/year at AF [≥]0.25, [≥]0.5, [≥]0.75 respectively. Mutation rate in {Delta}NSP-14 were significantly elevated at AF>0.25 vs wtNSP-14. Patients with immune comorbidities had higher mutation rate at all allele frequencies. Discussion: Intra-host SARS-CoV-2 mutation rates are substantially higher than those reported through population analysis. Virus strains with altered NSP-14 have accelerated mutation rate at low AF. Immunosuppressed patients have elevated mutation rate at all AF. Understanding intra-host virus evolution will aid in current and future pandemic modeling.


Sujets)
COVID-19 , Surdité aux hautes fréquences
14.
researchsquare; 2023.
Preprint Dans Anglais | PREPRINT-RESEARCHSQUARE | ID: ppzbmed-10.21203.rs.3.rs-2659085.v1

Résumé

In patients with moderate to severe coronavirus disease 2019 (COVID-19), both proteinuria and high plasma levels of soluble urokinase receptor (suPAR) are commonly observed. Here we show a new type of proteinuria originating as part of a viral response. Inoculation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused increased suPAR levels and glomerulopathy in African Green Monkeys. We developed a unique mouse model whereby inhaled variants of the SARS-CoV-2 spike S1 protein elicited proteinuria with high levels of suPAR. This proteinuric response was prevented by either suPAR blockade or prior SARS-CoV-2 vaccination. We demonstrate biophysical and functional differences of spike S1 protein between various SARS-CoV-2 variants and their binding to regulatory podocyte integrins. In a cohort of 1991 COVID-19 patients, suPAR levels exhibited a stepwise association with proteinuria in non-Omicron, but not in Omicron infections. These findings suggest that viral proteins may cause proteinuria by elevating plasma suPAR levels and co-activating podocyte integrins, thus providing a basis for understanding viral-associated proteinuria syndromes.


Sujets)
Infections à coronavirus , Protéinurie , Maladies du rein , COVID-19
15.
J Chin Med Assoc ; 86(3): 274-281, 2023 03 01.
Article Dans Anglais | MEDLINE | ID: covidwho-2222868

Résumé

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a global pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). It has brought tremendous challenges to public health and medical systems around the world. The current strategy for drug repurposing has accumulated some evidence on the use of N -acetylcysteine (NAC) in treating patients with COVID-19. However, the evidence remains debated. METHODS: We performed the systematic review and meta-analysis that complies with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five databases and reference lists were searched from inception to May 14, 2022. Studies evaluating the efficacy of NAC in treating patients with COVID-19 were regarded as eligible. The review was registered prospectively on PROSPERO (CRD42022332791). RESULTS: Of 778 records identified from the preliminary search, four studies were enrolled in the final qualitative review and quantitative meta-analysis. A total of 355 patients were allocated into the NAC group and the control group. The evaluated outcomes included intubation rate, improvement, duration of intensive unit stay and hospital stay and mortality. The pooled results showed nonsignificant differences in intubation rate (OR, 0.55; 95% CI, 0.16-1.89; p = 0.34; I2 = 75%), improvement of oxygenation ([MD], 80.84; 95% CI, -38.16 to 199.84; p = 0.18; I2 = 98%), ICU stay (MD, -0.74; 95% CI, -3.19 to 1.71; p = 0.55; I2 = 95%), hospital stay (MD, -1.05; 95% CI, -3.02 to 0.92; p = 0.30; I2 = 90%), and mortality (OR, 0.58; 95% CI, 0.23-1.45; p = 0.24; I2 = 54%). Subsequent trial sequential analysis (TSA) showed conclusive nonsignificant results for mortality, while the TSA for the other outcomes suggested that a larger sample size is essential. CONCLUSIONS: The current evidence reveals NAC is not beneficial for treating patients with COVID- 19 with regard to respiratory outcome, mortality, duration of ICU stay and hospital stay.


Sujets)
COVID-19 , Humains , Acétylcystéine/usage thérapeutique , SARS-CoV-2 , Durée du séjour
16.
Atmospheric Chemistry and Physics ; 23(2):1511-1532, 2023.
Article Dans Anglais | ProQuest Central | ID: covidwho-2217339

Résumé

Gaseous pollutants at the ground level seriously threaten the urban air quality environment and public health. There are few estimates of gaseous pollutants that are spatially and temporally resolved and continuous across China. This study takes advantage of big data and artificial-intelligence technologies to generate seamless daily maps of three major ambient pollutant gases, i.e., NO2, SO2, and CO, across China from 2013 to 2020 at a uniform spatial resolution of 10 km. Cross-validation between our estimates and ground observations illustrated a high data quality on a daily basis for surface NO2, SO2, and CO concentrations, with mean coefficients of determination (root-mean-square errors) of 0.84 (7.99 µg m-3), 0.84 (10.7 µg m-3), and 0.80 (0.29 mg m-3), respectively. We found that the COVID-19 lockdown had sustained impacts on gaseous pollutants, where surface CO recovered to its normal level in China on around the 34th day after the Lunar New Year, while surface SO2 and NO2 rebounded more than 2 times slower due to more CO emissions from residents' increased indoor cooking and atmospheric oxidation capacity. Surface NO2, SO2, and CO reached their peak annual concentrations of 21.3 ± 8.8 µg m-3, 23.1 ± 13.3 µg m-3, and 1.01 ± 0.29 mg m-3 in 2013, then continuously declined over time by 12 %, 55 %, and 17 %, respectively, until 2020. The declining rates were more prominent from 2013 to 2017 due to the sharper reductions in anthropogenic emissions but have slowed down in recent years. Nevertheless, people still suffer from high-frequency risk exposure to surface NO2 in eastern China, while surface SO2 and CO have almost reached the World Health Organization (WHO) recommended short-term air quality guidelines (AQG) level since 2018, benefiting from the implemented stricter "ultra-low” emission standards. This reconstructed dataset of surface gaseous pollutants will benefit future (especially short-term) air pollution and environmental health-related studies.

17.
Radiology of Infectious Diseases ; 9(3):100-103, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-2202113

Résumé

The spread of severe acute respiratory syndrome coronavirus 2 worldwide has created a major threat to human life and safety. Antiviral drugs and antibiotics have poor therapeutic effects, and there is no specific treatment for this virus. Chest computed tomography (CT) plays an important role in the diagnosis and management of coronavirus disease 2019 (COVID-19). We report a patient who was critically ill with COVID-19 and recovered after receiving transfusions of convalescent plasma. To evaluate the efficacy of convalescent plasma in the treatment of COVID-19, we compared chest CT findings, clinical manifestations, and laboratory findings before and after treatment with convalescent plasma. After the transfusion of convalescent plasma, clinical manifestations and indicators of inflammation improved, accompanied by an increase in the partial pressure of oxygen and oxygen saturation. Chest CT showed some resolution of the lung lesions, and multiple viral nucleic acid tests were negative. Therefore, the patient's condition was improved after the transfusion of convalescent plasma, suggesting that it may be an effective treatment for patients who are critically ill with COVID-19.

18.
Transitions ; 6(1-2):3-26, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-2197216

Résumé

Impacted by the global COVID-19 crisis and its sociopolitical shockwaves, pre-existing physical mobility patterns and traditional study-abroad experiences have been thoroughly disrupted and transformed. US higher education institutions have utilized the practices of transnational hybrid learning to sustain the quality and progress of international higher education. This article focuses on a study programme that integrates online and offline learning in Shanghai, China, coordinated by a non-profit international higher education exchange agency in partnership with eight US universities and one Chinese university from August 2020 to June 2021. Through semi-structured interviews with 32 Chinese students, this article finds that transnational hybrid learning offers students greater geographical and time flexibility, room for self-paced learning and controls on health risks while ensuring face-to-face interactions and physical activities. In addition, the localization of international education might motivate Chinese students to consider their career development that balances their interests and career prospects in response to political and economic uncertainties. However, the communication and learning gaps, weakened intercultural communication, sustained sociocultural alienation and contradictions of two sociocultural contexts render the overall programme experience less desirable. In sum, this article identifies the potential of virtual mobility beyond geographical and policy constraints in transforming and reimagining the practices of transnational higher education in a post-pandemic world.

19.
medrxiv; 2023.
Preprint Dans Anglais | medRxiv | ID: ppzbmed-10.1101.2022.12.28.22283666

Résumé

BACKGROUND This study has assessed a new Anti-COVID-19 Monoclonal Antibody Nasal Spray (SA58) for post-exposure prophylaxis (PEP) against symptomatic coronavirus disease 2019 (COVID-19). METHODS We conducted an efficacy study in adults aged 18 years and older within three days of exposure to a SARS-CoV-2 infected individual. Recruited participants were randomized in a ratio of 3:1 to receive SA58 or placebo. Primary endpoints were laboratory-confirmed symptomatic COVID-19 within study period. FINDINGS A total of 1,222 participants were randomized and dosed (SA58, n=901; placebo, n=321). Median of follow-up was 2.25 days and 2.79 days for SA58 and placebo, respectively. Adverse events occurred in 221 of 901 (25%) and 72 of 321 (22%) participants with SA58 and placebo, respectively, with no significant difference (P=0.49). All adverse events were mild in severity. Laboratory-confirmed symptomatic COVID-19 developed in 7 of 824 participants (0.22 per 100 person-days) in the SA58 group vs 14 of 299 (1.17 per 100 person-days) in the placebo group, resulting in an estimated efficacy of 80.82% (95%CI 52.41%-92.27%). There were 32 SARS-CoV-2 RT-PCR positives (1.04 per 100 person-days) in the SA58 group vs 32 (2.80 per 100 person-days) in the placebo group, resulting in an estimated efficacy of 61.83% (95%CI 37.50%-76.69%). A total of 21 RT-PCR positive samples were sequenced. 21 lineages of SARS-CoV-2 variants were identified, and all were the Omicron variant BF.7. INTERPRETATION SA58 Nasal Spray showed favorable efficacy and safety in preventing SARS-CoV-2 infection or symptomatic COVID-19 in healthy adult workers who had exposure to SARS-CoV-2 within 72 hours.


Sujets)
COVID-19 , Syndrome respiratoire aigu sévère
20.
COVID ; 2(12):1787-1805, 2022.
Article Dans Anglais | MDPI | ID: covidwho-2163259

Résumé

At the end of 2019, COVID-19 outbreaks occurred one after another in countries worldwide. Managing the outbreak efficiently and stably is an essential public health issue facing countries worldwide. In this paper, based on the SEIR model, we propose a SCEIR model that incorporates close contacts (C) and self-protectors (P). Firstly, the epidemic data of China, the USA, and Italy are predicted and compared with the actual data. Secondly, sensitivity analysis of each parameter in the SCEIR model was conducted using Anylogic. The study shows that the SCEIR model established in this paper has a certain validity. The infection rate in contact with E (𝛽) etc., has positive effects on the basic regeneration number (R0);the self-isolation rate (phi) etc., has a negative effect on the basic regeneration number (R0). Emergency management measures are proposed according to the influencing factors corresponding to the model parameters. These can provide theoretical guidance for developing effective epidemic prevention and control measures in areas where the epidemic has not yet been controlled. It also provides some reference for formulating prevention and control policies for similar epidemics that may occur in the future.

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