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1.
Microb Cell Fact ; 20(1): 95, 2021 May 05.
Article in English | MEDLINE | ID: covidwho-1216899

ABSTRACT

BACKGROUND: The global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlights the need to develop safe and effective vaccines with a top priority. Multiple vaccine candidates are under development, and several vaccines are currently available. Efforts need to be undertaken to counter the threat of the global COVID-19 pandemic. RESULTS: We generated a Saccharomyces cerevisiae (S. cerevisiae)-based SARS-CoV-2 vaccine, EBY100/pYD1-RBD, in which the full-length receptor binding domain (RBD) of the spike protein of SARS-CoV-2 was expressed on the surface of yeast. Mice vaccinated orally with unadjuvanted EBY100/pYD1-RBD could produce significant humoral and mucosal responses as well as robust cellular immune responses. Notably, EBY100/pYD1-RBD elicited a mixed Th1/Th2-type cellular immune response with a Th1-biased immune response in a mouse model. CONCLUSIONS: Our findings highlight the importance of the RBD as a key target to design and develop vaccines against SARS-CoV-2 and provide evidence of oral administration of a S. cerevisiae-based SARS-CoV-2 vaccine eliciting significant immune responses. Most importantly, the S. cerevisiae surface display system can serve as a universal technology platform and be applied to develop other oral viral or bacterial vaccines.


Subject(s)
/immunology , Immunity, Cellular , Saccharomyces cerevisiae , Spike Glycoprotein, Coronavirus/immunology , Administration, Oral , Animals , Binding Sites , /administration & dosage , Female , Immunity, Humoral , Immunity, Mucosal , Mice , Mice, Inbred BALB C
3.
Preprint | SciFinder | ID: ppcovidwho-3912

ABSTRACT

A review Since the occurrence of coronavirus disease 2019, the epidemic has progressed rapidly and seriously that threatened people's health At present, there is no specific drug for its treatment in clinic, and most of them are symptomatic treatment, mainly to delay the body damage caused by the new coronavirus, and it is urgent to find a safe and effective drug Chalcone and its derivatives have a wide range of pharmacol effects, such as antiviral, antibacterial, and anti-inflammatory, antioxidant, anti-fibrosis The pharmacol action and mechanism of chalcone and its derivatives are mainly summarized, and the feasibility of its application in the prevention and treatment of coronavirus disease 2019 is discussed, which may provide reference for clin treatment

4.
Infect Dis Ther ; 9(4): 1003-1015, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-917172

ABSTRACT

BACKGROUND: Metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) has the potential to improve the pathogen identification in severe community-acquired pneumonia (SCAP). METHODS: In this 1.5-year, multicenter, prospective study, we investigated the usefulness of mNGS of BALF for identifying pathogens of SCAP in hospitalized adults, comparing it with other laboratory methods. RESULTS: Of 329 SCAP adults, a microbial etiology was established in 304 cases (92.4%). The overall microbial yield was 90.3% for mNGS versus 39.5% for other methods (P < 0.05). The most frequently detected pathogens in immunocompetent patients were Streptococcus pneumoniae (14.8%), rhinovirus (9.8%), Haemophilus influenzae (9.1%), Staphylococcus aureus (8.7%), and Chlamydia psittaci (8.0%), while in immunocompromised patients they were Pneumocystis jirovecii (44.6%), Klebsiella pneumoniae (18.5%), Streptococcus pneumoniae (15.4%), Haemophilus influenzae (13.8%), and Pseudomonas aeruginosa (13.8%). Notably, novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified from two patients solely by mNGS in January 2020; uncommon pathogens including Orientia tsutsugamushi and Nocardia otitidiscaviarum were identified from one patient, respectively. Furthermore, mixed infections were detected in 56.8% of the patients. CONCLUSIONS: A high microbial detection rate was achieved in SCAP adults using mNGS testing of BALF. The most frequently detected pathogens of SCAP differed between immunocompetent and immunocompromised patients. mNGS testing may be an powerful tool for early identification of potential pathogens for SCAP to initiate a precise antimicrobial therapy.

5.
Ann Med ; 53(1): 34-42, 2021 12.
Article in English | MEDLINE | ID: covidwho-720886

ABSTRACT

BACKGROUND: Studies have demonstrated the diagnostic efficiency of antibody testing in COVID-19 infection. There is limited data on the IgM/IgG changes in asymptomatic and discharged patients with reoccurring positive nucleic acid test (RPNAT). This study aims to investigate these IgM/IgG changes. METHODS: There were 111 patients with positive nucleic acid test (NAT) and 40 suspected patients enrolled in the study. The serum SARS-CoV-2 specific IgM/IgG antibody levels were retrospectively analysed with the disease progress in asymptomatic and RPNAT patients. RESULTS: The best overall performance was found by combining the IgM, IgG, and CT; 95.1% sensitivity and 75% specificity. This was tested in 111 RT-PCR positive cases. The median IgM and IgG levels were lower in the asymptomatic group compared to the symptomatic group (p < .01). Among 15 RPNAT cases, the IgM levels of the RPNAT group at the time of discharge (IgM2.79, IQR: 0.95-5.37) and retest (IgM 2.35, IQR: 0.88-8.65) were significantly higher than those of the non-reoccurring positive nucleic acid test group (Non-RPNAT) (IgM on discharge: 0.59, IQR: 0.33-1.22, IgG on retest: 0.92, IQR: 0.51-1.58). CONCLUSION: Serum SARS-CoV-2 specific IgM/IgG antibody levels remained at a low level during hospitalisation for asymptomatic patients. Elevated IgM levels may have implications in the identification of RPNAT patients before discharge. Key messages This study determined the IgM/IgG changes in asymptomatic and RPNAT patients. The rate of serum SARS-CoV-2 specific IgM/IgG antibody levels increase in the asymptomatic group was lower than in the symptomatic group during hospitalisation. The IgM level did not decrease significantly at discharge in the RPNAT patients, and was higher than that of the Non-RPNAT group on discharge. These results highlight the importance of timely monitoring of IgM levels to identify RPNAT patients before discharge.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/isolation & purification , Coronavirus Infections/immunology , Immunoglobulin G/blood , Immunoglobulin M/blood , Pneumonia, Viral/immunology , Case-Control Studies , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Female , Humans , Immunoenzyme Techniques/methods , Male , Pandemics , Retrospective Studies
6.
Nature ; 582(7812): 389-394, 2020 06.
Article in English | MEDLINE | ID: covidwho-147207

ABSTRACT

Sudden, large-scale and diffuse human migration can amplify localized outbreaks of disease into widespread epidemics1-4. Rapid and accurate tracking of aggregate population flows may therefore be epidemiologically informative. Here we use 11,478,484 counts of mobile phone data from individuals leaving or transiting through the prefecture of Wuhan between 1 January and 24 January 2020 as they moved to 296 prefectures throughout mainland China. First, we document the efficacy of quarantine in ceasing movement. Second, we show that the distribution of population outflow from Wuhan accurately predicts the relative frequency and geographical distribution of infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) until 19 February 2020, across mainland China. Third, we develop a spatio-temporal 'risk source' model that leverages population flow data (which operationalize the risk that emanates from epidemic epicentres) not only to forecast the distribution of confirmed cases, but also to identify regions that have a high risk of transmission at an early stage. Fourth, we use this risk source model to statistically derive the geographical spread of COVID-19 and the growth pattern based on the population outflow from Wuhan; the model yields a benchmark trend and an index for assessing the risk of community transmission of COVID-19 over time for different locations. This approach can be used by policy-makers in any nation with available data to make rapid and accurate risk assessments and to plan the allocation of limited resources ahead of ongoing outbreaks.


Subject(s)
Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Disease Outbreaks/statistics & numerical data , Pneumonia, Viral/epidemiology , Pneumonia, Viral/transmission , Population Dynamics/statistics & numerical data , Spatio-Temporal Analysis , Travel/statistics & numerical data , China/epidemiology , Cities/epidemiology , Coronavirus Infections/diagnosis , Datasets as Topic , Geographic Mapping , Humans , Mobile Applications , Models, Biological , Pandemics , Pneumonia, Viral/diagnosis , Public Health/statistics & numerical data
7.
J Evid Based Med ; 13(1): 3-7, 2020 Feb.
Article in English | MEDLINE | ID: covidwho-707

ABSTRACT

OBJECTIVES: To estimate the basic reproduction number of the Wuhan novel coronavirus (2019-nCoV). METHODS: Based on the susceptible-exposed-infected-removed (SEIR) compartment model and the assumption that the infectious cases with symptoms occurred before 26 January, 2020 are resulted from free propagation without intervention, we estimate the basic reproduction number of 2019-nCoV according to the reported confirmed cases and suspected cases, as well as the theoretical estimated number of infected cases by other research teams, together with some epidemiological determinants learned from the severe acute respiratory syndrome (SARS). RESULTS: The basic reproduction number fall between 2.8 and 3.3 by using the real-time reports on the number of 2019-nCoV-infected cases from People's Daily in China and fall between 3.2 and 3.9 on the basis of the predicted number of infected cases from international colleagues. CONCLUSIONS: The early transmission ability of 2019-nCoV is close to or slightly higher than SARS. It is a controllable disease with moderate to high transmissibility. Timely and effective control measures are needed to prevent the further transmissions.


Subject(s)
Basic Reproduction Number , Betacoronavirus , Coronavirus Infections , Pneumonia, Viral , China/epidemiology , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/transmission , Forecasting , Humans , Models, Theoretical , Pneumonia, Viral/epidemiology , Pneumonia, Viral/prevention & control , Pneumonia, Viral/transmission
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