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1.
American journal of translational research ; 14(4):2655-2667, 2022.
Article in English | EuropePMC | ID: covidwho-1837264

ABSTRACT

Purpose: To investigate changes in the production of IgM and IgG antibodies and the negative transformation of viral nucleic acids in COVID-19 patients after convalescent plasma therapy, and also to discuss the clinical therapeutic effect, so as to provide a basis for the treatment of COVID-19 using specific antibodies. Methods: The convalescent plasma of recovered patients from COVID-19 was used to treat other patients, and the levels of antibodies IgM and IgG and the nucleic acid genes ORF1ab and N in the patients were tested regularly for statistical comparison and analysis. Results: In general, the Ct value and concentration of IgM and IgG antibodies in the plasma infusion group were significantly higher (1-3 times higher) than those in the non-plasma infusion group, respectively, but these differences were not significant (P>0.05). However, the content of antibodies in severe patients in the plasma transfusion group was significantly higher than those in the non-plasma transfusion group at discharge, the results being statistically significant (P<0.05). Conclusions: The application of convalescent plasma significantly increases the antibody content in severe and critical inpatients, effectively enhances immune function, accelerates the clearance of virus and the nucleic acid negative conversion rate, and significantly promotes early improvement in COVID-19 patients.

2.
Open Forum Infect Dis ; 9(5): ofac142, 2022 May.
Article in English | MEDLINE | ID: covidwho-1788525

ABSTRACT

Background: Population-based seroprevalence studies offer comprehensive characterization of coronavirus disease 2019 (COVID-19) spread, but barriers exist and marginalized populations may not be captured. We assessed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody seroprevalence among decedents in Maryland over 6 months in 2020. Methods: Data were collected on decedents undergoing forensic postmortem examination in Maryland from 24 May through 30 November 2020 from whom a blood specimen could be collected. Those with available blood specimens were tested with the CoronaCHEK lateral flow antibody assay. We assessed monthly seroprevalence compared to the statewide estimated number of cases and proportion of positive test results (testing positivity). We used Poisson regression with robust variance to estimate adjusted prevalence ratios (aPRs) with 95% confidence intervals (CIs) for associations of demographic characteristics, homelessness, and manner of death with SARS-CoV-2 antibodies. Results: Among 1906 decedents, 305 (16%) were positive for SARS-CoV-2 antibodies. Monthly seroprevalence increased from 11% to 22% over time and was consistently higher than state-level estimates of testing positivity. Hispanic ethnicity was associated with 2- to 3.2-fold higher seropositivity (P < .05) irrespective of sex. Deaths due to motor vehicle crash were associated with 62% increased seropositivity (aPR, 1.62 [95% CI, 1.15-2.28]) vs natural manner of death. Though seroprevalence was lower in decedents of illicit drug overdose vs nonoverdose in early months, this shifted, and seroprevalence was comparable by November 2020. Conclusions: Decedents undergoing forensic postmortem examination, especially those dying due to motor vehicle trauma, may be a sentinel population for COVID-19 spread in the general population and merits exploration in other states/regions.

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-333139

ABSTRACT

Introduction: The COVID-19 pandemic has resulted in a global crisis in public health, however, there are still no safe and effective drugs to resist COVID-19 until now. We will use network meta-analysis to analysis available evidence from RCTs to compare the safety and efficacy of four antiviral drugs (including Ribavirin, Arbidol, Chloroquine Phosphate and Interferon) alone or in combination, in patients with COVID-19 on the basis of standard treatment, to reveal the robustness and strength of evidence for relative efficacy against COVID-19, which will provide better evidence for future clinical decision-making. Methods Using English and Chinese search strategies to search 8 databases including PubMed, Web of Science, Embase, the Cochrane Library, CNKI, CBM, WANFANG Database and VIP. In addition, manual search for references in publications has been supplemented by electronic search. To enhance the effectiveness of this study, only randomized controlled trials of four antiviral drugs (Ribavirin, Arbidol, Chloroquine Phosphate, Interferon) used alone or in combination with the primary therapy shall be included.   Analysis The nucleic acid turning negative, complete absorption of lung inflammation, adverse reactions, aggravation and death shall be the primary outcome measures;whereas temperature return to normal, hospitalization, and positive rate after discharge will be the secondary outcomes. To ensure the quality of the systematic evaluation of this study, study screening, data extraction and quality evaluation will be carried out independently by two reviewers, and any differences will be resolved through consultation between them or by a third reviewer. Ethics and dissemination This systematic review will evaluate the efficacy of four antiviral drugs (Ribavirin, Arbidol, Chloroquine Phosphate and Interferon) for Covid-19 in adults. Since all included data will be obtained from published articles, it does not require ethical approval and will be published in a peer-reviewed journal. PROSPERO registration number: CRD42022300104.

4.
Open forum infectious diseases ; 9(5), 2022.
Article in English | EuropePMC | ID: covidwho-1781870

ABSTRACT

Background Population-based seroprevalence studies offer comprehensive characterization of coronavirus disease 2019 (COVID-19) spread, but barriers exist and marginalized populations may not be captured. We assessed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody seroprevalence among decedents in Maryland over 6 months in 2020. Methods Data were collected on decedents undergoing forensic postmortem examination in Maryland from 24 May through 30 November 2020 from whom a blood specimen could be collected. Those with available blood specimens were tested with the CoronaCHEK lateral flow antibody assay. We assessed monthly seroprevalence compared to the statewide estimated number of cases and proportion of positive test results (testing positivity). We used Poisson regression with robust variance to estimate adjusted prevalence ratios (aPRs) with 95% confidence intervals (CIs) for associations of demographic characteristics, homelessness, and manner of death with SARS-CoV-2 antibodies. Results Among 1906 decedents, 305 (16%) were positive for SARS-CoV-2 antibodies. Monthly seroprevalence increased from 11% to 22% over time and was consistently higher than state-level estimates of testing positivity. Hispanic ethnicity was associated with 2- to 3.2-fold higher seropositivity (P < .05) irrespective of sex. Deaths due to motor vehicle crash were associated with 62% increased seropositivity (aPR, 1.62 [95% CI, 1.15–2.28]) vs natural manner of death. Though seroprevalence was lower in decedents of illicit drug overdose vs nonoverdose in early months, this shifted, and seroprevalence was comparable by November 2020. Conclusions Decedents undergoing forensic postmortem examination, especially those dying due to motor vehicle trauma, may be a sentinel population for COVID-19 spread in the general population and merits exploration in other states/regions. SARS-CoV-2 antibody seroprevalence was 16% among Maryland decedents undergoing forensic postmortem examination (May–November 2020). Hispanic ethnicity and motor vehicle deaths were associated with seropositivity. Estimates in decedents exemplify feasible/real-time data for disease spread and potential sentinel surveillance meriting exploration.

5.
JAMA Neurol ; 79(6): 544-553, 2022 Jun 01.
Article in English | MEDLINE | ID: covidwho-1782548

ABSTRACT

Importance: Loss of smell is an early and common presentation of COVID-19 infection. Although it has been speculated that viral infection of olfactory neurons may be the culprit, it is unclear whether viral infection causes injuries in the olfactory bulb region. Objective: To characterize the olfactory pathology associated with COVID-19 infection in a postmortem study. Design, Setting, and Participants: This multicenter postmortem cohort study was conducted from April 7, 2020, to September 11, 2021. Deceased patients with COVID-19 and control individuals were included in the cohort. One infant with congenital anomalies was excluded. Olfactory bulb and tract tissue was collected from deceased patients with COVID-19 and appropriate controls. Histopathology, electron microscopy, droplet digital polymerase chain reaction, and immunofluorescence/immunohistochemistry studies were performed. Data analysis was conducted from February 7 to October 19, 2021. Main Outcomes and Measures: (1) Severity of degeneration, (2) losses of olfactory axons, and (3) severity of microvasculopathy in olfactory tissue. Results: Olfactory tissue from 23 deceased patients with COVID-19 (median [IQR] age, 62 [49-69] years; 14 men [60.9%]) and 14 control individuals (median [IQR] age, 53.5 [33.25-65] years; 7 men [50%]) was included in the analysis. The mean (SD) axon pathology score (range, 1-3) was 1.921 (0.569) in patients with COVID-19 and 1.198 (0.208) in controls (P < .001), whereas axon density was 2.973 (0.963) × 104/mm2 in patients with COVID-19 and 3.867 (0.670) × 104/mm2 in controls (P = .002). Concomitant endothelial injury of the microvasculature was also noted in olfactory tissue. The mean (SD) microvasculopathy score (range, 1-3) was 1.907 (0.490) in patients with COVID-19 and 1.405 (0.233) in control individuals (P < .001). Both the axon and microvascular pathology was worse in patients with COVID-19 with smell alterations than those with intact smell (mean [SD] axon pathology score, 2.260 [0.457] vs 1.63 [0.426]; P = .002; mean [SD] microvasculopathy score, 2.154 [0.528] vs 1.694 [0.329]; P = .02) but was not associated with clinical severity, timing of infection, or presence of virus. Conclusions and Relevance: This study found that COVID-19 infection is associated with axon injuries and microvasculopathy in olfactory tissue. The striking axonal pathology in some cases indicates that olfactory dysfunction in COVID-19 infection may be severe and permanent.


Subject(s)
COVID-19 , Olfaction Disorders , Cohort Studies , Humans , Male , Middle Aged , Olfaction Disorders/etiology , SARS-CoV-2 , Smell/physiology
7.
Sustainability ; 14(7):4290, 2022.
Article in English | MDPI | ID: covidwho-1776341

ABSTRACT

Enterprises performing complex product servitization are more vulnerable to the 2019 coronavirus disease (COVID-19) pandemic because of their large number of suppliers and wide coverage, among other things. The present research focuses on how to promote the sustainable innovation of complex product servitization. We investigate complex products and sustainable innovation-factors influencing the sustainable innovation of complex product servitization-based on the characteristics of product servitization and by combining the definitions of product servitization. We find that inadequate innovation ability and poor technical research and development (R&D) competence are the primary concerns in the sustainable innovation of complex product servitization. Specific to innovation ability improvement, the sustainable innovation of complex product servitization must follow an innovation-driven development strategy, a hard power cultivation strategy, and a soft power cultivation strategy. In terms of technical R&D competence enhancement, technological innovation strategies, integrated outsourcing of technical R&D competence, and independent improvement of technical R&D competence must be implemented to facilitate the sustainable innovation of complex product servitization.

8.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-331882

ABSTRACT

Background: As COVID-19 evolved into a global pandemic. Increasing numbers of reports have linked obesity to more severe COVID-19 illness and death (1-3). However, almost all the studies focused on the proportion of people entering the ICU or mortality. Is obesity also associated with severity of pneumonia in common pneumonia patients? How about underweight patients? The answer is lack. So, our research below will answer the question. Methods: We collected and analyzed epidemiological, demographic, clinical, and laboratory data from 193 confirmed cases of COVID-19 at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology in Wuhan, China, between January 1, 2020, and March 13, 2020. They were followed up until April 15, 2020. Results: Among these patients, 5.70% were underweight, 58.03% were normal weight, 27.98% were overweight and 8.29% were obese. underweight patients were more likely to have headache (P=0.029) Obese patients were more likely to experience a decline in lymphocyte counts(P=0.042), an increase in CRP(P=0.020), bilateral multiple mottling and groundglass opacity (P=0.008). Besides, the proportion of patients receiving human immunoglobulin+systematic corticosteroids treatment is the highest among the obese group compared with other BMI groups. After adjusting for potential confounders, Underweight patients had 6.483-fold higher(P=0.012),and obesity patients showed 5.965-fold higher odds developing acute lung injury(ALI) than normal weight patients(P=0.022). Underweight patients were 3.255 times more likely than normal-weight patients to develop secondary infections (P=0.041). Conclusions: Our study shows that in patients with common pneumonia, both underweight and obese people tend to develop ALI compared with normal weight patients.

9.
Mamm Genome ; 33(1): 143-156, 2022 03.
Article in English | MEDLINE | ID: covidwho-1767484

ABSTRACT

Mouse models are essential for dissecting disease mechanisms and defining potential drug targets. There are more than 18,500 mouse strains available for research communities in National Resource Center for Mutant Mice (NRCMM) of China, affiliated with Model Animal Research Center of Nanjing University and Gempharmatech Company. In 2019, Gempharmatech launched the Knockout All Project (KOAP) aiming to generate null mutants and gene floxed strains for all protein-coding genes in mouse genome within 5 years. So far, KOAP has generated 8,004 floxed strains and 9,769 KO (knockout) strains (updated to Oct, 2021). NRCMM also created hundreds of Cre transgenic lines, mutant knock-in models, immuno-deficient models, and humanized mouse models. As a member of the international mouse phenotyping consortium (IMPC), NRCMM provides comprehensive phenotyping services for mouse models. In summary, NRCMM will continue to support biomedical community with new mouse models as well as related services.


Subject(s)
Genome , Animals , China , Disease Models, Animal , Humans , Mice , Mice, Knockout , Phenotype
10.
World journal of psychiatry ; 12(2):338-347, 2022.
Article in English | EuropePMC | ID: covidwho-1749852

ABSTRACT

BACKGROUND Frontline nurses in Wuhan directly fighting severe acute respiratory syndrome coronavirus-2 diseases are at a high risk of infection and are extremely susceptible to psychological stress, especially due to the global coronavirus disease 2019 (COVID-19) pandemic. The psychological after-effects of this public health emergency on frontline nurses will last for years. AIM To assess factors influencing post-traumatic stress disorder (PTSD) among frontline nurses in Wuhan 6 mo after the COVID-19 pandemic began. METHODS A total of 757 frontline nurses from five hospitals in Wuhan, China, participated in an online survey from July 27 to August 13, 2020. This cross-sectional online study used a demographic information questionnaire, the PTSD Checklist for the Diagnostic and Statistical Manual of Mental Disorders, the Connor-Davidson Resilience Scale, and the Patient Health Questionnaire-4. The chi-square test and logistic regression were used to analyze the association of demographics, COVID-19-related variables, and PTSD. Logistic regression was also conducted to investigate which variables were associated with PTSD outcomes. RESULTS A total of 13.5%, 24.3%, and 21.4% of the frontline nurses showed symptoms of PTSD, depression, and anxiety, respectively. The multivariate logistic regression analysis showed that the following factors were strongly associated with PTSD: Having a relative, friend, or colleague who died of COVID-19;experiencing stigma;or having psychological assistance needs, depressive symptoms or anxiety. Showing resilience and receiving praise after the COVID-19 outbreak were protective factors. CONCLUSION Frontline nurses still experienced PTSD (13.5%) six months after the COVID-19 outbreak began. Peer support, social support, official recognition, reward mechanisms, exercise, better sleep, and timely provision of information (such as vaccine research progress) by the government via social media, and adequate protective supplies could mitigate the level of PTSD among nurses responding to COVID-19. Stigmatization, depression, and anxiety might be associated with a greater risk of PTSD among nurses.

11.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-330227

ABSTRACT

Cytokine storm is a primary cause for multiple organ damage and death after severe infections, such as SARS-CoV-2. However, current single cytokine-targeted strategies display limited therapeutic efficacy. Here, we report that peritoneal M2 macrophages-derived extracellular vesicles (M2-EVs) are multi-target nanotherapeutics to resolve cytokine storm. In detail, primary peritoneal M2 macrophages exhibited superior anti-inflammatory potential than immobilized cell lines. Systemically administrated M2-EVs entered major organs and were taken up by phagocytes (e.g., macrophages). M2-EVs treatment effectively reduced excessive cytokine (e.g., TNF-α and IL-6) release in vitro and in vivo, thereby attenuated oxidative stress and multiple organ (lung, liver, spleen and kidney) damage in endotoxin-induced cytokine storm. Moreover, M2-EVs simultaneously inhibited multiple key proinflammatory pathways (e.g., NF-κB, JAK-STAT and p38 MAPK) by regulating complex miRNA-gene and gene-gene networks, and this effect was collectively mediated by many functional cargos (miRNAs and proteins) in EVs. In addition to the direct anti-inflammatory role, human peritoneal M2-EVs expressed angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2 spike protein, and thus could serve as nanodecoys to prevent SARS-CoV-2 pseudovirus infection in vitro. As cell-derived nanomaterials, the therapeutic index of M2-EVs can be further improved by genetic/chemical modification or loading with specific drugs. This study highlights that peritoneal M2-EVs are promising multifunctional nanotherapeutics to attenuate infectious diseases-related cytokine storm.

12.
Nat Commun ; 13(1): 915, 2022 02 17.
Article in English | MEDLINE | ID: covidwho-1703249

ABSTRACT

Quantitative or qualitative differences in immunity may drive clinical severity in COVID-19. Although longitudinal studies to record the course of immunological changes are ample, they do not necessarily predict clinical progression at the time of hospital admission. Here we show, by a machine learning approach using serum pro-inflammatory, anti-inflammatory and anti-viral cytokine and anti-SARS-CoV-2 antibody measurements as input data, that COVID-19 patients cluster into three distinct immune phenotype groups. These immune-types, determined by unsupervised hierarchical clustering that is agnostic to severity, predict clinical course. The identified immune-types do not associate with disease duration at hospital admittance, but rather reflect variations in the nature and kinetics of individual patient's immune response. Thus, our work provides an immune-type based scheme to stratify COVID-19 patients at hospital admittance into high and low risk clinical categories with distinct cytokine and antibody profiles that may guide personalized therapy.


Subject(s)
Antibodies, Viral/blood , COVID-19/pathology , Cytokines/blood , SARS-CoV-2/immunology , Severity of Illness Index , Aged , Coronavirus Nucleocapsid Proteins/immunology , Disease Progression , Female , Hospitalization , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Immunophenotyping/methods , Machine Learning , Male , Middle Aged , Phosphoproteins/immunology
13.
PLoS Comput Biol ; 18(2): e1009807, 2022 02.
Article in English | MEDLINE | ID: covidwho-1699463

ABSTRACT

Estimating the changes of epidemiological parameters, such as instantaneous reproduction number, Rt, is important for understanding the transmission dynamics of infectious diseases. Current estimates of time-varying epidemiological parameters often face problems such as lagging observations, averaging inference, and improper quantification of uncertainties. To address these problems, we propose a Bayesian data assimilation framework for time-varying parameter estimation. Specifically, this framework is applied to estimate the instantaneous reproduction number Rt during emerging epidemics, resulting in the state-of-the-art 'DARt' system. With DARt, time misalignment caused by lagging observations is tackled by incorporating observation delays into the joint inference of infections and Rt; the drawback of averaging is overcome by instantaneously updating upon new observations and developing a model selection mechanism that captures abrupt changes; the uncertainty is quantified and reduced by employing Bayesian smoothing. We validate the performance of DARt and demonstrate its power in describing the transmission dynamics of COVID-19. The proposed approach provides a promising solution for making accurate and timely estimation for transmission dynamics based on reported data.


Subject(s)
Basic Reproduction Number , Bayes Theorem , COVID-19/epidemiology , SARS-CoV-2/isolation & purification , Algorithms , COVID-19/transmission , COVID-19/virology , Humans , SARS-CoV-2/physiology
14.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-315253

ABSTRACT

This paper studies the spatial impact of COVID-19 pandemic through the lens of intra-city population and house rent changes in Beijing, China. Drawing on multiple geospatial data sets, we find that the pandemic has flattened the housing bid-rent curve in Beijing, which corroborates existing literature mainly based on cities in developed countries. Through regression analysis and spatial equilibrium modelling, we identify key mechanisms of the flattened bid-rent curve and the accompanying decentralisation of residents. First, workplace population change, particularly in central Beijing, seems to be the main factor contributing to the resident population and house rent changes. Second, we find no significant evidence on the spatial impact from remote working, as the share of remote working in Beijing appears low after about one year recovery. This finding contrasts to existing studies where remote working has been perceived as the main driver for urban spatial structure change in a developed country context. Third, through a novel method for quantifying locational preference changes, it is found that the observed decentralisation trend in Beijing, ceteris paribus, may also be associated with increased (decreased) preference for living in suburban (central) locations. However, the preference change for central locations is marginal, hence providing an early rebuttal of the ‘demise of centres’ proposition.

15.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327290

ABSTRACT

Major cell entry factors of SARS-CoV-2 are present in neurons;however, the neurotropism of SARS-CoV-2 and the phenotypes of infected neurons are still unclear. Acute neurological disorders occur in many patients, and one-third of COVID-19 survivors suffer from brain diseases. Here, we show that SARS-CoV-2 invades the brains of five patients with COVID-19 and Alzheimers, autism, frontotemporal dementia or no underlying condition by infecting neurons and other cells in the cortex. SARS-CoV-2 induces or enhances Alzheimers-like neuropathology with manifestations of beta-amyloid aggregation and plaque formation, tauopathy, neuroinflammation and cell death. SARS-CoV-2 infects mature but not immature neurons derived from inducible pluripotent stem cells from healthy and Alzheimers individuals through its receptor ACE2 and facilitator neuropilin-1. SARS-CoV-2 triggers Alzheimers-like gene programs in healthy neurons and exacerbates Alzheimers neuropathology. A gene signature defined as an Alzheimers infectious etiology is identified through SARS-CoV-2 infection, and silencing the top three downregulated genes in human primary neurons recapitulates the neurodegenerative phenotypes of SARS-CoV-2. Thus, SARS-CoV-2 invades the brain and activates an Alzheimers-like program.

16.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-324518

ABSTRACT

In epidemiological modelling, the instantaneous reproduction number, R t , is important to understand the transmission dynamics of infectious diseases. Current R t estimates often suffer from problems such as lagging, averaging and uncertainties demoting the usefulness of R t . To address these problems, we propose a new method in the framework of sequential Bayesian inference where a Data Assimilation approach is taken for R t estimation, resulting in the state-of-the-art ‘DARt’ system for R t estimation. With DARt, the problem of time misalignment caused by lagging observations is tackled by incorporating observation delays into the joint inference of infections and R t ;the drawback of averaging is improved by instantaneous updating upon new observations and a model selection mechanism capturing abrupt changes caused by interventions;the uncertainty is quantified and reduced by employing Bayesian smoothing. We validate the performance of DARt through simulations and demonstrate its power in revealing the transmission dynamics of COVID-19.

17.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-324517

ABSTRACT

In epidemiological modelling, the instantaneous reproduction number, $R_t$, is important to understand the transmission dynamics of infectious diseases. Current $R_t$ estimates often suffer from problems such as lagging, averaging and uncertainties demoting the usefulness of $R_t$. To address these problems, we propose a new method in the framework of sequential Bayesian inference where a Data Assimilation approach is taken for $R_t$ estimation, resulting in the state-of-the-art 'DAR$_t$' system for $R_t$ estimation. With DAR$_t$, the problem of time misalignment caused by lagging observations is tackled by incorporating observation delays into the joint inference of infections and $R_t$;the drawback of averaging is improved by instantaneous updating upon new observations and a model selection mechanism capturing abrupt changes caused by interventions;the uncertainty is quantified and reduced by employing Bayesian smoothing. We validate the performance of DAR$_t$ through simulations and demonstrate its power in revealing the transmission dynamics of COVID-19.

18.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-323696

ABSTRACT

Epidemic models play a key role in understanding and responding to the emerging COVID-19 pandemic. Widely used compartmental models are static and are of limited use to evaluate intervention strategies with the emerging pandemic. Applying the technology of data assimilation, we propose a Bayesian updating approach for estimating epidemiological parameters using observable information for the purpose of assessing the impacts of different intervention strategies. We adopt a concise renewal model and propose new parameters by disentangling the reduction of instantaneous reproduction number Rt into mitigation and suppression factors for quantifying intervention impacts at a finer granularity. Then we developed a data assimilation framework for estimating these parameters including constructing an observation function and developing a Bayesian updating scheme. A statistical analysis framework is then built to quantify the impact of intervention strategies by monitoring the evolution of these estimated parameters. By Investigating the impacts of intervention measures of European countries, the United States and Wuhan with the framework, we reveal the effects of interventions in these countries and the resurgence risk in the USA.

20.
Zhongguo Bingdubing Zazhi = Chinese Journal of Viral Diseases ; - (6):438, 2021.
Article in English | ProQuest Central | ID: covidwho-1675353

ABSTRACT

:Objective To study the kinetics of IgM and IgG antibodies based on nucleocapsid(N) and spike(S) protein of SARS-Co V2-in COVID-19 patients. Methods Immunofluorescent kits were used to detect N and S protein specific IgM and IgG antibodies from Jan.21 to Feb.11, 2020 for the 60 hospitalized COVID-19 patients(48 mild, 12 severe cases) with a total of 290 plasma samples collected 9 weeks after the onset of the disease. Results The level of antibodies specific for S protein varied significantly with the course of disease(Ig M from 27.32 to 110.10 TU/ml, IgG from 56.85 to 135.00 TU/ml), but not for N protein.Higher level of Ig M/Ig G antibodies specific to S protein was observed during the 2-7 week than that to N protein.The seropositive rate of antibodies gradually increased during the early stage of disease.IgM/IgG antibodies specific to N protein changed from 12.50% at the first week to peak level(51.72% and 86.21% respectively) at the 4 th week and those for S protein from 25.00% and 14.58% to 100.00%, and then declined.The seropositive rate of Ig M antibody specific to S protein was higher than that for N protein during 2-8 th week and that for Ig G antibody at 2, 3, 4, 6 and 7 th week.The seropositive rate of Ig G antibody specific to N protein in severe patients at the third week was higher than that in mild patients(100.00% vs 59.52%,χ2=9.67, P=0.001 9), and the same as to Ig G antibody for S protein at the second week after disease onset(80.00% vs 46.58%, χ2=5.57, P=0.018 2). Conclusions SARS-Co V2-S protein can induc stronger antibody response than N protein, and the antibody level was related to the severity of the disease.

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