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1.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-315306

ABSTRACT

The emergence of numerous variants of SARS-CoV-2, the causative agent of COVID-19, has presented new challenges to the global efforts to control the still ravaging COVID-19 pandemic. Here, we obtain two cross-neutralizing antibodies (7D6 and 6D6) that target Sarbecoviruses’ receptor binding domain (RBD) with sub-picomolar affinities and potently neutralize authentic SARS-CoV-2. Crystal structures show that both antibodies bind a cryptic site different from that recognized by existing antibodies and highly conserved across Sarbecovirus isolates. Binding of these two antibodies to the RBD clashes with the adjacent N-terminal domain and disrupts the viral spike. Significantly, both antibodies confer good mutation resistance to the currently circulating SARS-CoV-2 variants. Thus, our results have direct relevance to public health as options for passive antibody therapeutics and even active prophylactics, and can also inform the design of pan-sarbecovirus vaccines.

2.
Emerg Microbes Infect ; 9(1): 2105-2113, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-913100

ABSTRACT

The global pandemic of coronavirus disease 2019 (COVID-19) is a disaster for human society. A convenient and reliable neutralization assay is very important for the development of vaccines and novel drugs. In this study, a G protein-deficient vesicular stomatitis virus (VSVdG) bearing a truncated spike protein (S with C-terminal 18 amino acid truncation) was compared to that bearing the full-length spike protein of SARS-CoV-2 and showed much higher efficiency. A neutralization assay was established based on VSV-SARS-CoV-2-Sdel18 pseudovirus and hACE2-overexpressing BHK21 cells (BHK21-hACE2 cells). The experimental results can be obtained by automatically counting the number of EGFP-positive cells at 12 h after infection, making the assay convenient and high-throughput. The serum neutralizing titer measured by the VSV-SARS-CoV-2-Sdel18 pseudovirus assay has a good correlation with that measured by the wild type SARS-CoV-2 assay. Seven neutralizing monoclonal antibodies targeting the receptor binding domain (RBD) of the SARS-CoV-2 S protein were obtained. This efficient and reliable pseudovirus assay model could facilitate the development of new drugs and vaccines.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Betacoronavirus/immunology , Coronavirus Infections/diagnosis , Neutralization Tests/methods , Pneumonia, Viral/diagnosis , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 , Cell Line , Chlorocebus aethiops , Cricetinae , Pandemics , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , Vero Cells , Vesicular stomatitis Indiana virus/genetics , Vesicular stomatitis Indiana virus/immunology
3.
CAplus; 2020.
Preprint | CAplus | ID: ppcovidwho-2015

ABSTRACT

A review. The article listed some epidemiol. key concepts involved in the outbreak of novel coronavirus pneumonia (COVID-19) as well as some examples of epidemiol. terminol. understanding deviation in reports, news conferences and interviews from the authorities and social media in the period from 21st Jan. 2020 to 14th Feb.We corrected the errors in the examples and illustrated the concept of terminologies. The basic epidemiol. concepts and the importance of public health should be introduced to the public by the health authorities.

4.
Eur Respir J ; 56(2)2020 08.
Article in English | MEDLINE | ID: covidwho-744959

ABSTRACT

BACKGROUND: Timely diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a prerequisite for treatment and prevention. The serology characteristics and complement diagnosis value of the antibody test to RNA test need to be demonstrated. METHOD: Serial sera of 80 patients with PCR-confirmed coronavirus disease 2019 (COVID-19) were collected at the First Affiliated Hospital of Zhejiang University, Hangzhou, China. Total antibody (Ab), IgM and IgG antibodies against SARS-CoV-2 were detected, and the antibody dynamics during the infection were described. RESULTS: The seroconversion rates for Ab, IgM and IgG were 98.8%, 93.8% and 93.8%, respectively. The first detectible serology marker was Ab, followed by IgM and IgG, with a median seroconversion time of 15, 18 and 20 days post exposure (d.p.e.) or 9, 10 and 12 days post onset (d.p.o.), respectively. The antibody levels increased rapidly beginning at 6 d.p.o. and were accompanied by a decline in viral load. For patients in the early stage of illness (0-7 d.p.o), Ab showed the highest sensitivity (64.1%) compared with IgM and IgG (33.3% for both; p<0.001). The sensitivities of Ab, IgM and IgG increased to 100%, 96.7% and 93.3%, respectively, 2 weeks later. When the same antibody type was detected, no significant difference was observed between enzyme-linked immunosorbent assays and other forms of immunoassays. CONCLUSIONS: A typical acute antibody response is induced during SARS-CoV-2 infection. Serology testing provides an important complement to RNA testing in the later stages of illness for pathogenic-specific diagnosis and helpful information to evaluate the adapted immunity status of patients.


Subject(s)
Betacoronavirus , Clinical Laboratory Techniques , Coronavirus Infections/blood , Coronavirus Infections/diagnosis , Pneumonia, Viral/blood , Pneumonia, Viral/diagnosis , Adult , Aged , COVID-19 , COVID-19 Testing , China , Coronavirus Infections/complications , Female , Hospitalization , Humans , Infectious Disease Incubation Period , Male , Middle Aged , Pandemics , Pneumonia, Viral/complications , SARS-CoV-2 , Sensitivity and Specificity , Seroconversion , Symptom Assessment , Time Factors , Viral Load
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