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1.
Vaccines (Basel) ; 8(2)2020 Mar 29.
Article in English | MEDLINE | ID: covidwho-1726034

ABSTRACT

In December 2019, the outbreak of pneumonia caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a serious pandemic in China and other countries worldwide. So far, more than 460,000 confirmed cases were diagnosed in nearly 190 countries, causing globally over 20,000 deaths. Currently, the epidemic is still spreading and there is no effective means to prevent the infection. Vaccines are proved to be the most effective and economical means to prevent and control infectious diseases. Several countries, companies, and institutions announced their programs and progress on vaccine development against the virus. While most of the vaccines are under design and preparation, there are some that have entered efficacy evaluation in animals and initial clinical trials. This review mainly focused on the progress and our prospects on field of vaccine development against SARS-CoV-2.

2.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-315360

ABSTRACT

The main protease (Mpro) is one of the best-characterized drug targets among coronaviruses. In the current study, we adopted a multiple cross-docking strategy against different crystal structures of SARS-CoV-2 Mpro to perform computer-based high-throughput virtual screening of possible inhibitors from a drug database using Autodock Vina and SeeSAR software, combined with our in-house automatic processing scripts. The KDs between screened candidates and Mpro were determined using Biacore. Seven drugs were found to fit the substrate-binding pocket of Mpro with a stable conformation, showing high KDs that ranged from 6.79E-7 M to 5.20E-5 M. Finally, mutagenesis studies confirmed that these drugs interact with Mpro specifically, suggesting that our method was reliable and convincing. Given the safety of these old drugs, they may serve as promising candidates to treat the infection of SARS-CoV-2. Our results also provide rational explanations for the behaviour of five drugs evaluated in clinical trials.

3.
Virol J ; 18(1): 209, 2021 10 21.
Article in English | MEDLINE | ID: covidwho-1484316

ABSTRACT

BACKGROUND: Porcine vesicular disease is caused by the Seneca Valley virus (SVV), it is a novel Picornaviridae, which is prevalent in several countries. However, the pathogenicity of SVV on 5-6 week old pigs and the transmission routes of SVV remain unknown. METHODS: This research mainly focuses on the pathogenicity of the CH-GX-01-2019 strain and the possible vector of SVV. In this study, 5-6 week old pigs infected with SVV (CH-GX-01-2019) and its clinical symptoms (including rectal temperatures and other clinical symptoms) were monitored, qRT-PCR were used to detect the viremia and virus distribution. Neutralization antibody assay was set up during this research. Mosquitoes and Culicoides were collected from pigsties after pigs challenge with SVV, and SVV detection within mosquitoes and Culicoides was done via RT-PCR. RESULTS: The challenged pigs presented with low fevers and mild lethargy on 5-8 days post infection. The viremia lasted more than 14 days. SVV was detected in almost all tissues on the 14th day following the challenge, and it was significantly higher in the hoofs (vesicles) and lymph nodes in comparison with other tissues. Neutralizing antibodies were also detected and could persist for more than 28 days, in addition neutralizing antibody titers ranged from 1:128 to 1:512. Mosquitoes and Culicoides were collected from the pigsty environments following SVV infection. Although SVV was not detected in the mosquitoes, it was present in the Culicoides, however SVV could not be isolated from the positive Culicoides. CONCLUSIONS: Our work has enriched the knowledge relating to SVV pathogenicity and possible transmission routes, which may lay the foundation for further research into the prevention and control of this virus.


Subject(s)
Ceratopogonidae , Picornaviridae Infections , Picornaviridae , Swine Diseases , Animals , Farms , Mosquito Vectors , Picornaviridae Infections/veterinary , Swine , Virulence
4.
Front Immunol ; 12: 757691, 2021.
Article in English | MEDLINE | ID: covidwho-1463478

ABSTRACT

The increase in confirmed COVID-19 cases and SARS-CoV-2 variants calls for the development of safe and broad cross-protective vaccines. The RBD of the spike protein was considered to be a safe and effective candidate antigen. However, the low immunogenicity limited its application in vaccine development. Herein, we designed and obtained an RBD heptamer (mHla-RBD) based on a carrier protein-aided assembly strategy. The molecular weight of mHla-RBD is up to 450 kDa, approximately 10 times higher than that of the RBD monomer. When formulated with alum adjuvant, mHla-RBD immunization significantly increased the immunogenicity of RBD, as indicated by increased titers of RBD-specific antibodies, neutralizing antibodies, Th2 cellular immune response, and pseudovirus neutralization activity, when compared to RBD monomer. Furthermore, we confirmed that RBD-specific antibodies predominantly target conformational epitopes, which was approximately 200 times that targeting linear epitopes. Finally, a pseudovirus neutralization assay revealed that neutralizing antibodies induced by mHla-RBD against different SARS-CoV-2 variants were comparable to those against the wild-type virus and showed broad-spectrum neutralizing activity toward different SARS-CoV-2 variants. Our results demonstrated that mHla-RBD is a promising candidate antigen for development of SARS-CoV-2 vaccines and the mHla could serve as a universal carrier protein for antigen design.


Subject(s)
Bacterial Proteins/metabolism , COVID-19 Vaccines/immunology , COVID-19/immunology , Carrier Proteins/metabolism , Hemolysin Proteins/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Th2 Cells/immunology , Animals , Antibodies, Neutralizing/metabolism , Antibodies, Viral/metabolism , Broadly Neutralizing Antibodies/metabolism , Cell Line , Escherichia coli Proteins , Humans , Lymphocyte Activation , Mice , Mice, Inbred BALB C , Protein Domains/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
6.
Signal Transduct Target Ther ; 5(1): 219, 2020 10 06.
Article in English | MEDLINE | ID: covidwho-834865

ABSTRACT

Convalescent plasma (CP) transfusion has been indicated as a promising therapy in the treatment for other emerging viral infections. However, the quality control of CP and individual variation in patients in different studies make it rather difficult to evaluate the efficacy and risk of CP therapy for coronavirus disease 2019 (COVID-19). We aimed to explore the potential efficacy of CP therapy, and to assess the possible factors associated with its efficacy. We enrolled eight critical or severe COVID-19 patients from four centers. Each patient was transfused with 200-400 mL of CP from seven recovered donors. The primary indicators for clinical efficacy assessment were the changes of clinical symptoms, laboratory parameters, and radiological image after CP transfusion. CP donors had a wide range of antibody levels measured by serology tests which were to some degree correlated with the neutralizing antibody (NAb) level. No adverse events were observed during and after CP transfusion. Following CP transfusion, six out of eight patients showed improved oxygen support status; chest CT indicated varying degrees of absorption of pulmonary lesions in six patients within 8 days; the viral load was decreased to a negative level in five patients who had the previous viremia; other laboratory parameters also tended to improve, including increased lymphocyte counts, decreased C-reactive protein, procalcitonin, and indicators for liver function. The clinical efficacy might be associated with CP transfusion time, transfused dose, and the NAb levels of CP. This study indicated that CP might be a potential therapy for severe patients with COVID-19.


Subject(s)
Antibodies, Neutralizing/administration & dosage , Antibodies, Viral/administration & dosage , Betacoronavirus/pathogenicity , Coronavirus Infections/therapy , Pneumonia, Viral/therapy , Adult , Aged , Antiviral Agents/therapeutic use , Betacoronavirus/immunology , Biomarkers/blood , C-Reactive Protein/metabolism , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Coronavirus Infections/diagnostic imaging , Coronavirus Infections/immunology , Coronavirus Infections/pathology , Disease Progression , Female , Humans , Immunization, Passive/methods , Liver Function Tests , Male , Middle Aged , Pandemics , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/immunology , Pneumonia, Viral/pathology , Procalcitonin/blood , SARS-CoV-2 , Severity of Illness Index , Tomography, X-Ray Computed , Viral Load
7.
Virus Res ; 278: 197869, 2020 03.
Article in English | MEDLINE | ID: covidwho-2388

ABSTRACT

Porcine deltacoronavirus (PDCoV) is the etiological agent of acute diarrhoea and vomiting in pigs, threatening the swine industry worldwide. Although several PDCoV studies have been conducted in China, more sequence information is needed to understand the molecular characterization of PDCoV. In this study, the partial ORF1a, spike protein (S) and nucleocapsid protein (N) were sequenced from Shandong Province between 2017 and 2018. The sequencing results for the S protein from 10 PDCoV strains showed 96.7 %-99.7 % nucleotide sequence identity with the China lineage strains, while sharing a lower level of nucleotide sequence identity, ranging from 95.7 to 96.8%, with the Vietnam/Laos/Thailand lineage strains. N protein sequencing analysis showed that these strains showed nucleotide homologies of 97.3%-99.3% with the reference strains. Phylogenetic analyses based on S protein sequences showed that these PDCoV strains were classified into the China lineage. The discontinuous 2 + 3 aa deletions at 400-401 and 758-760 were found in the Nsp2 and Nsp3 coding region in five strains, respectively, with similar deletions having been identified in Vietnam, Thailand, and Laos. Three novel patterns of deletion were observed for the first time in the Nsp2 and Nsp3 regions. Importantly, those findings suggest that PDCoV may have undergone a high degree of variation since PDCoV was first detected in China.


Subject(s)
Coronavirus Infections/veterinary , Deltacoronavirus/classification , Deltacoronavirus/genetics , Genome, Viral , Phylogeny , Animals , China/epidemiology , Coronavirus Infections/epidemiology , Diarrhea/virology , Feces/virology , Gene Deletion , Prevalence , Swine , Swine Diseases/virology , Viral Proteins/genetics
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