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2.
Clin Infect Dis ; 2021 Oct 05.
Article in English | MEDLINE | ID: covidwho-1769226

ABSTRACT

BACKGROUND: The longitudinal antigen-specific immunity in COVID-19 convalescents is crucial for long-term protection upon individual re-exposure to SARS-CoV-2, and even more pivotal for ultimately achieving population-level immunity. To better understand the features of immune memory in individuals with different disease severities at one year post-disease onset we conducted this cohort study. METHODS: We conducted a systematic antigen-specific immune evaluation in 101 COVID-19 convalescents, who had asymptomatic, mild, moderate, or severe disease, through two visits at months 6 and 12 post-disease onset. The SARS-CoV-2-specific antibodies, comprising NAb, IgG, and IgM, were assessed by mutually corroborated assays, i.e. neutralization, enzyme-linked immunosorbent assay (ELISA), and microparticle chemiluminescence immunoassay (MCLIA). Meanwhile, the T-cell memory against SARS-CoV-2 spike, membrane and nucleocapsid proteins was tested through enzyme-linked immunospot assay (ELISpot), intracellular cytokine staining (ICS), and tetramer staining-based flow cytometry, respectively. RESULTS: SARS-CoV-2-specific IgG antibodies, and also NAb can persist among over 95% COVID-19 convalescents from 6 months to 12 months after disease onset. At least 19/71 (26%) of COVID-19 convalescents (double positive in ELISA and MCLIA) had detectable circulating IgM antibody against SARS-CoV-2 at 12m post-disease onset. Notably, the percentages of convalescents with positive SARS-CoV-2-specific T-cell responses (at least one of the SARS-CoV-2 antigen S1, S2, M and N protein) were 71/76 (93%) and 67/73 (92%) at 6m and 12m, respectively. Furthermore, both antibody and T-cell memory levels of the convalescents were positively associated with their disease severity. CONCLUSIONS: SARS-CoV-2-specific cellular and humoral immunities are durable at least until one year after disease onset.

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-329581

ABSTRACT

Emerging in December 2019, coronavirus disease 2019 (COVID-19) eventually became a pandemic and has posed a tremendous threat to global public health. However, the origins of SARS-CoV-2, the causative agent of COVID-19, remain to be determined. It has reported that a certain number of the early case clusters had a contact history with Huanan Seafood Market. Therefore, surveillance of SARS-CoV-2 within the market is of vital importance. Herein, we presented the SARS-CoV-2 detection results of 1380 samples collected from the environment and the animals within the market in early 2020. By SARS-CoV-2-specific RT-qPCR, 73 environmental samples tested positive for SARS-CoV-2 and three live viruses were successfully isolated. The viruses from the market shared nucleotide identity of 99.980% to 99.993% with the human isolate HCoV/Wuhan/IVDC-HB-01. In contrast, no virus was detected in the animal swabs covering 18 species of animals in the market. The SARS-COV-2 nucleic acids in the positive environmental samples showed significant correlation of abundance of Homo sapiens with SARS-CoV-2. In summary, this study provided convincing evidence of the prevalence of SARS-CoV-2 in the Huanan Seafood Market during the early stage of COVID-19 outbreak.

4.
Nat Immunol ; 23(3): 423-430, 2022 03.
Article in English | MEDLINE | ID: covidwho-1713201

ABSTRACT

The global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic requires effective therapies against coronavirus disease 2019 (COVID-19), and neutralizing antibodies are a promising therapy. A noncompeting pair of human neutralizing antibodies (B38 and H4) blocking SARS-CoV-2 binding to its receptor, ACE2, have been described previously. Here, we develop bsAb15, a bispecific monoclonal antibody (bsAb) based on B38 and H4. bsAb15 has greater neutralizing efficiency than these parental antibodies, results in less selective pressure and retains neutralizing ability to most SARS-CoV-2 variants of concern (with more potent neutralizing activity against the Delta variant). We also selected for escape mutants of the two parental mAbs, a mAb cocktail and bsAb15, demonstrating that bsAb15 can efficiently neutralize all single-mAb escape mutants. Furthermore, prophylactic and therapeutic application of bsAb15 reduced the viral titer in infected nonhuman primates and human ACE2 transgenic mice. Therefore, this bsAb is a feasible and effective strategy to treat and prevent severe COVID-19.


Subject(s)
Antibodies, Bispecific/immunology , Antibodies, Monoclonal/immunology , Antibodies, Viral/immunology , SARS-CoV-2/immunology , Animals , Antibodies, Bispecific/chemistry , Antibodies, Bispecific/genetics , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/genetics , Antibodies, Neutralizing/genetics , Antibodies, Neutralizing/immunology , Antibodies, Viral/chemistry , Antibodies, Viral/genetics , COVID-19/immunology , COVID-19/pathology , COVID-19/prevention & control , COVID-19/virology , Cloning, Molecular , Disease Models, Animal , Dose-Response Relationship, Immunologic , Epitopes , Humans , Macaca mulatta , Mice , Neutralization Tests , Protein Engineering/methods , Structure-Activity Relationship
5.
Science ; 375(6584): 1048-1053, 2022 03 04.
Article in English | MEDLINE | ID: covidwho-1673339

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant has become the dominant infective strain. We report the structures of the Omicron spike trimer on its own and in complex with angiotensin-converting enzyme 2 (ACE2) or an anti-Omicron antibody. Most Omicron mutations are located on the surface of the spike protein and change binding epitopes to many current antibodies. In the ACE2-binding site, compensating mutations strengthen receptor binding domain (RBD) binding to ACE2. Both the RBD and the apo form of the Omicron spike trimer are thermodynamically unstable. An unusual RBD-RBD interaction in the ACE2-spike complex supports the open conformation and further reinforces ACE2 binding to the spike trimer. A broad-spectrum therapeutic antibody, JMB2002, which has completed a phase 1 clinical trial, maintains neutralizing activity against Omicron. JMB2002 binds to RBD differently from other characterized antibodies and inhibits ACE2 binding.


Subject(s)
Angiotensin-Converting Enzyme 2/chemistry , Antibodies, Neutralizing/chemistry , Antibodies, Viral/chemistry , SARS-CoV-2/chemistry , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/metabolism , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/immunology , Antibodies, Viral/metabolism , Binding Sites , Cryoelectron Microscopy , Epitopes , Humans , Immunoglobulin Fab Fragments/chemistry , Immunoglobulin Fab Fragments/immunology , Immunoglobulin Fab Fragments/metabolism , Models, Molecular , Mutation , Protein Binding , Protein Conformation , Protein Domains , Protein Interaction Domains and Motifs , Protein Multimerization , Protein Subunits/chemistry , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Thermodynamics
6.
iScience ; 25(1): 103720, 2022 Jan 21.
Article in English | MEDLINE | ID: covidwho-1665029

ABSTRACT

It is unknown whether antibody-mediated enhancement (ADE) contributes to the pathogenesis of COVID-19, and the conditions for ADE needs to be elucidated. We demonstrated that without inducing an ACE2-independent ADE on Raji cells, the neutralizing antibody CB6, a mouse anti-S1 serum and convalescent plasma, induced ADE on cells expressing FcγRIIA/CD32A and low levels of endogenous ACE2. ADE occurred at sub-neutralizing antibody concentrations, indicating that unneutralized S protein was required for ADE. The enhanced infectivity of 614G variant was higher than that of 614D wildtype in the presence of antibodies, further suggesting that ADE may be influenced by virus strains with different ACE2-binding affinity. Finally, knockdown of ACE2 or treatment with a fusion-inhibition peptide EK1C4 significantly reduced ADE. In conclusion, we identified an ADE mechanism mediated by neutralizing antibodies against SARS-CoV-2. ACE2 may act as a secondary receptor required for the antibody- and FcγR-mediated enhanced entry of SARS-CoV-2.

7.
Hum Immunol ; 83(2): 119-129, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1499900

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the pandemic of coronavirus disease 2019 (COVID-19). Great international efforts have been put into the development of prophylactic vaccines and neutralizing antibodies. However, the knowledge about the B cell immune response induced by the SARS-CoV-2 virus is still limited. Here, we report a comprehensive characterization of the dynamics of immunoglobin heavy chain (IGH) repertoire in COVID-19 patients. By using next-generation sequencing technology, we examined the temporal changes in the landscape of the patient's immunological status and found dramatic changes in the IGH within the patient's immune system after the onset of COVID-19 symptoms. Although different patients have distinct immune responses to SARS-CoV-2 infection, by employing clonotype overlap, lineage expansion, and clonotype network analyses, we observed a higher clonotype overlap and substantial lineage expansion of B cell clones 2-3 weeks after the onset of illness, which is of great importance to B-cell immune responses. Meanwhile, for preferences of V gene usage during SARS-CoV-2 infection, IGHV3-74 and IGHV4-34, and IGHV4-39 in COVID-19 patients were more abundant than those of healthy controls. Overall, we present an immunological resource for SARS-CoV-2 that could promote both therapeutic development as well as mechanistic research.


Subject(s)
Antibodies, Viral/immunology , B-Lymphocytes/immunology , COVID-19/immunology , Receptors, Antigen, B-Cell/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged, 80 and over , Antibodies, Neutralizing/immunology , Female , Humans , Immunoglobulin Heavy Chains/immunology , Male , Middle Aged
8.
Clin Infect Dis ; 2021 Oct 05.
Article in English | MEDLINE | ID: covidwho-1450372

ABSTRACT

BACKGROUND: The longitudinal antigen-specific immunity in COVID-19 convalescents is crucial for long-term protection upon individual re-exposure to SARS-CoV-2, and even more pivotal for ultimately achieving population-level immunity. To better understand the features of immune memory in individuals with different disease severities at one year post-disease onset we conducted this cohort study. METHODS: We conducted a systematic antigen-specific immune evaluation in 101 COVID-19 convalescents, who had asymptomatic, mild, moderate, or severe disease, through two visits at months 6 and 12 post-disease onset. The SARS-CoV-2-specific antibodies, comprising NAb, IgG, and IgM, were assessed by mutually corroborated assays, i.e. neutralization, enzyme-linked immunosorbent assay (ELISA), and microparticle chemiluminescence immunoassay (MCLIA). Meanwhile, the T-cell memory against SARS-CoV-2 spike, membrane and nucleocapsid proteins was tested through enzyme-linked immunospot assay (ELISpot), intracellular cytokine staining (ICS), and tetramer staining-based flow cytometry, respectively. RESULTS: SARS-CoV-2-specific IgG antibodies, and also NAb can persist among over 95% COVID-19 convalescents from 6 months to 12 months after disease onset. At least 19/71 (26%) of COVID-19 convalescents (double positive in ELISA and MCLIA) had detectable circulating IgM antibody against SARS-CoV-2 at 12m post-disease onset. Notably, the percentages of convalescents with positive SARS-CoV-2-specific T-cell responses (at least one of the SARS-CoV-2 antigen S1, S2, M and N protein) were 71/76 (93%) and 67/73 (92%) at 6m and 12m, respectively. Furthermore, both antibody and T-cell memory levels of the convalescents were positively associated with their disease severity. CONCLUSIONS: SARS-CoV-2-specific cellular and humoral immunities are durable at least until one year after disease onset.

9.
Lancet Infect Dis ; 22(2): 196-208, 2022 02.
Article in English | MEDLINE | ID: covidwho-1414105

ABSTRACT

BACKGROUND: Although SARS-CoV-2 infection often causes milder symptoms in children and adolescents, young people might still play a key part in SARS-CoV-2 transmission. An efficacious vaccine for children and adolescents could therefore assist pandemic control. For further evaluation of the inactivated COVID-19 vaccine candidate BBIBP-CorV, we assessed the safety and immunogenicity of BBIBP-CorV in participants aged 3-17 years. METHODS: A randomised, double-blind, controlled, phase 1/2 trial was done at Shangqiu City Liangyuan District Center for Disease Control and Prevention in Henan, China. In phases 1 and 2, healthy participants were stratified according to age (3-5 years, 6-12 years, or 13-17 years) and dose group. Individuals with a history of SARS-CoV-2 or SARS-CoV infection were excluded. All participants were randomly assigned, using stratified block randomisation (block size eight), to receive three doses of 2 µg, 4 µg, or 8 µg of vaccine or control (1:1:1:1) 28 days apart. The primary outcome, safety, was analysed in the safety set, which consisted of participants who had received at least one vaccination after being randomly assigned, and had any safety evaluation information. The secondary outcomes were geometric meant titre (GMT) of the neutralising antibody against infectious SARS-CoV-2 and were analysed based on the full analysis set. This study is registered with www.chictr.org.cn, ChiCTR2000032459, and is ongoing. FINDINGS: Between Aug 14, 2020, and Sept 24, 2020, 445 participants were screened, and 288 eligible participants were randomly assigned to vaccine (n=216, 24 for each dose level [2/4/8 µg] in each of three age cohorts [3-5, 6-12, and 13-17 years]) or control (n=72, 24 for each age cohort [3-5, 6-12, and 13-17 years]) in phase 1. In phase 2, 810 participants were screened and 720 eligible participants were randomly assigned and allocated to vaccine (n=540, 60 for each dose level [2/4/8 µg] in each of three age cohorts [3-5, 6-12, and 13-17 years]) or control (n=180, 60 for each age cohort [3-5, 6-12, and 13-17 years]). The most common injection site adverse reaction was pain (ten [4%] 251 participants in all vaccination groups of the 3-5 years cohort; 23 [9·1%] of 252 participants in all vaccination groups and one [1·2%] of 84 in the control group of the 6-12 years cohort; 20 [7·9%] of 252 participants in all vaccination groups of the 13-17 years cohort). The most common systematic adverse reaction was fever (32 [12·7%] of 251 participants in all vaccination groups and six [7·1%] of 84 participants in the control group of the 3-5 years cohort; 13 [5·2%] of 252 participants in the vaccination groups and one [1·2%] of 84 in the control group of the 6-12 years cohort; 26 [10·3%] of 252 participants in all vaccination groups and eight [9·5%] of 84 in the control group of the 13-17 years cohort). Adverse reactions were mostly mild to moderate in severity. The neutralising antibody GMT against the SARS-CoV-2 virus ranged from 105·3 to 180·2 in the 3-5 years cohort, 84·1 to 168·6 in the 6-12 years cohort, and 88·0 to 155·7 in the 13-17 years cohort on day 28 after the second vaccination; and ranged from 143·5 to 224·4 in the 3-5 years cohort, 127 to 184·8 in the 6-12 years cohort, and 150·7 to 199 in the 13-17 years cohort on day 28 after the third vaccination. INTERPRETATION: The inactivated COVID-19 vaccine BBIBP-CorV is safe and well tolerated at all tested dose levels in participants aged 3-17 years. BBIBP-CorV also elicited robust humoral responses against SARS-CoV-2 infection after two doses. Our findings support the use of a 4 µg dose and two-shot regimen BBIBP-CorV in phase 3 trials in the population younger than 18 years to further ascertain its safety and protection efficacy against COVID-19. FUNDING: National Program on Key Research Project of China, National Mega projects of China for Major Infectious Diseases, National Mega Projects of China for New Drug Creation, and Beijing Science and Technology Plan. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19 Vaccines/standards , COVID-19/prevention & control , Adolescent , COVID-19 Vaccines/administration & dosage , Child , Child, Preschool , Cohort Studies , Double-Blind Method , Female , Humans , Male , Vaccines, Inactivated/immunology , Vaccines, Inactivated/standards
10.
Appl Phys Lett ; 119(9): 090601, 2021 Aug 30.
Article in English | MEDLINE | ID: covidwho-1392984

ABSTRACT

A variety of pathogens can cause people to suffer from serious diseases, and the transmission of COVID-19 through the cold chain has once again attracted people's attention to cold chain disinfection. Unfortunately, there is no mature cold chain disinfection technique yet. In this study, a low-temperature plasma disinfection technique for a cold chain is proposed. The disinfection effect of plasma generated by surface dielectric barrier discharge on Escherichia coli in ice at cryogenic temperature is studied, and the possible disinfection mechanism is discussed. It is found that the O3 mode and the NOx mode also exist in the surface dielectric barrier discharge at cryogenic temperature, just as at room temperature. The disinfection effect of both modes is weak in 5 min plasma treatment, but in 60 min post-treatment, the NOx mode shows a stronger disinfection effect, with 4.45 log reduction. It is speculated that gaseous H2O2 and NOx can be adsorbed on the ice surface in the NOx mode and then converted into peroxynitrite, which is a powerful bactericidal species. In conclusion, a low-temperature plasma is a promising technique for cold chain disinfection, which is of great significance for ensuring people's health.

11.
J Virol ; 95(22): e0117321, 2021 10 27.
Article in English | MEDLINE | ID: covidwho-1371847

ABSTRACT

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has reignited global interest in animal coronaviruses and their potential for human transmission. While bats are thought to be the wildlife reservoir of SARS-CoV and SARS-CoV-2, the widespread human coronavirus OC43 is thought to have originated in rodents. Here, we sampled 297 rodents and shrews, representing eight species, from three municipalities of southern China. We report coronavirus prevalences of 23.3% and 0.7% in Guangzhou and Guilin, respectively, with samples from urban areas having significantly higher coronavirus prevalences than those from rural areas. We obtained three coronavirus genome sequences from Rattus norvegicus, including a Betacoronavirus (rat coronavirus [RCoV] GCCDC3), an Alphacoronavirus (RCoV-GCCDC5), and a novel Betacoronavirus (RCoV-GCCDC4). Recombination analysis suggests that there was a potential recombination event involving RCoV-GCCDC4, murine hepatitis virus (MHV), and Longquan Rl rat coronavirus (LRLV). Furthermore, we uncovered a polybasic cleavage site, RARR, in the spike (S) protein of RCoV-GCCDC4, which is dominant in RCoV. These findings provide further information on the potential for interspecies transmission of coronaviruses and demonstrate the value of a One Health approach to virus discovery. IMPORTANCE Surveillance of viruses among rodents in rural and urban areas of South China identified three rodent coronaviruses, RCoV-GCCDC3, RCoV-GCCDC4, and RCoV-GCCDC5, one of which was identified as a novel potentially recombinant coronavirus with a polybasic cleavage site in the spike (S) protein. Through reverse transcription-PCR (RT-PCR) screening of coronaviruses, we found that coronavirus prevalence in urban areas is much higher than that in rural areas. Subsequently, we obtained three coronavirus genome sequences by deep sequencing. After different method-based analyses, we found that RCoV-GCCDC4 was a novel potentially recombinant coronavirus with a polybasic cleavage site in the S protein, dominant in RCoV. This newly identified coronavirus RCoV-GCCDC4 with its potentially recombinant genome and polybasic cleavage site provides a new insight into the evolution of coronaviruses. Furthermore, our results provide further information on the potential for interspecies transmission of coronaviruses and demonstrate the necessity of a One Health approach for zoonotic disease surveillance.


Subject(s)
Coronavirus Infections/veterinary , Coronavirus/genetics , Recombination, Genetic , Rodentia/virology , Spike Glycoprotein, Coronavirus/genetics , Amino Acid Sequence , Animals , China/epidemiology , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Evolution, Molecular , Genome, Viral/genetics , Humans , Phylogeny , Prevalence , Shrews/virology
12.
Biosafety and Health ; 2021.
Article in English | ScienceDirect | ID: covidwho-1370453

ABSTRACT

Mink has been identified as an animal with susceptibility to SARS-CoV-2 and also as the only animal with evidence to transmit the virus back to humans. Thus, the surveillance of viruses among high-density farmed minks has a significant meaning for the control of zoonotic emerging diseases in humans. Within anal swabs of minks that died of unknown causes in a mink farm, mink calicivirus (MCV) and mammalian reovirus (MRV) were detected and simultaneously observed within MDCK cell culture from the sample of the same lethal mink. The parallel isolation was successfully performed by utilizing cell lines from different host sources with distinct viral sensitivities, i.e. Mv.1.Lu and Vero-E6 and the two viruses were independently separated. The prevalence of the virus among the minks and its genomic characteristics were investigated through deep sequencing technology. Phylogenetic analysis of the viral genome showed a close relationship of the newly isolated MCV-GCCDC8-2020 with MCV strains belonging to the genus Vesivirus, but with unique mutations derived from the major structural protein (VP1). The reovirus MRV-GCCDC9-2020 isolated from the same mink belongs to serotype 3 mammalian reovirus and genome analysis showed a potential reassortment derived from reoviruses in different species. This study provides a beneficial reference on viral co-infection within disease investigation in farmed minks and raises the concern for the virus surveillance among the high-density fed animal farms.

15.
China CDC Wkly ; 3(30): 637-644, 2021 Jul 23.
Article in English | MEDLINE | ID: covidwho-1317436

ABSTRACT

What is already known about this topic? Though coronavirus disease 2019 (COVID-19) has largely been controlled in China, several outbreaks of COVID-19 have occurred from importation of cases or of suspected virus-contaminated products. Though several outbreaks have been traced to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolated on the outer packaging of cold chain products, live virus has not been obtained. What is added by this report? In September 2020, two dock workers were detected as having asymptomatic SARS-CoV-2 infection using throat swabs during routine screening in Qingdao, China. Epidemiological information showed that the two dock workers were infected after contact with contaminated outer packaging, which was confirmed by genomic sequencing. Compared to the Wuhan reference strain, the sequences from the dock workers and the package materials differed by 12-14 nucleotides. Furthermore, infectious virus from the cold chain products was isolated by cell culture, and typical SARS-CoV-2 particles were observed under electron microscopy. What are the implications for public health practice? The international community should pay close attention to SARS-CoV-2 transmission mode through cold chain, build international cooperative efforts in response, share relevant data, and call on all countries to take effective prevention and control measures to prevent virus contamination in cold-chain food production, marine fishing and processing, transportation, and other operations.

16.
MAbs ; 13(1): 1930636, 2021.
Article in English | MEDLINE | ID: covidwho-1258715

ABSTRACT

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease-2019 (COVID-19), interacts with the host cell receptor angiotensin-converting enzyme 2 (hACE2) via its spike 1 protein during infection. After the virus sequence was published, we identified two potent antibodies against the SARS-CoV-2 receptor binding domain (RBD) from antibody libraries using a phage-to-yeast (PtY) display platform in only 10 days. Our lead antibody JMB2002, now in a Phase 1 clinical trial (ChiCTR2100042150), showed broad-spectrum in vitro blocking activity against hACE2 binding to the RBD of multiple SARS-CoV-2 variants, including B.1.351 that was reportedly much more resistant to neutralization by convalescent plasma, vaccine sera and some clinical-stage neutralizing antibodies. Furthermore, JMB2002 has demonstrated complete prophylactic and potent therapeutic efficacy in a rhesus macaque disease model. Prophylactic and therapeutic countermeasure intervention of SARS-CoV-2 using JMB2002 would likely slow down the transmission of currently emerged SARS-CoV-2 variants and result in more efficient control of the COVID-19 pandemic.


Subject(s)
Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Antibodies, Neutralizing/pharmacology , Antiviral Agents/pharmacology , COVID-19/drug therapy , COVID-19/prevention & control , SARS-CoV-2/drug effects , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , Antibody Specificity , Binding Sites, Antibody , CHO Cells , COVID-19/immunology , COVID-19/metabolism , COVID-19/virology , Chlorocebus aethiops , Cricetulus , Disease Models, Animal , Epitopes , Macaca mulatta , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Vero Cells
17.
Int J Neurosci ; : 1-20, 2021 Mar 26.
Article in English | MEDLINE | ID: covidwho-1114761

ABSTRACT

Purpose: As of November 28, 2020, COVID-19 has been reported in 220 countries with 61,036,793 confirmed cases and 1,433,316 confirmed deaths; countries became vigilant around the world. In addition to SARS-CoV-2 causing pneumonia, many studies have reported ischemic stroke in patients with COVID-19. This article describes the effects and possible underlying mechanisms of SARS-CoV-2 on ischemic stroke.Materials and methods: A literature search was performed using PubMed, Web of Science, and other COVID-dedicated databases and the combination of the keywords 'SARS-CoV-2', 'COVID-19' and 'ischemic stroke' up to November 28, 2020.Results: SARS-CoV-2 invades the host through angiotensin converting enzyme 2 (ACE2). ACE2 is expressed not only in the lungs, but also in the brain and vascular endothelial cells. SARS-CoV-2 infection might cause direct vascular disease or enhance the immunogenic thrombosis environment through several mechanisms. SARS-CoV-2 infection can modulate the host immune response and can cause inflammation, coagulation disorders, renin angiotensin system disorders, hypoxia, and stress disorders, which may lead to the occurrence of ischemic stroke.Conclusions: Some patients with COVID-19 can develop ischemic stroke. Ischemic stroke has a high risk of causing disability and is associated with a high mortality rate. It is hoped that when medical staff treat patients with COVID-19, they would pay attention to the occurrence of ischemic stroke to improve the prognosis of patients with COVID-19.

18.
JCI Insight ; 6(4)2021 02 22.
Article in English | MEDLINE | ID: covidwho-1039950

ABSTRACT

The coronavirus disease 19 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become the worst public health crisis in a century. However, knowledge about the dynamics of antibody responses in patients with COVID-19 is still poorly understood. In this study, we performed a serological study with serum specimens collected at the acute and the convalescent phases from 104 patients with severe COVID-19 who were part of the first wave of COVID-19 cases in Wuhan, China. Our findings revealed that neutralizing antibodies to SARS-CoV-2 are persistent for at least 6 months in patients with severe COVID-19, despite that IgG levels against the receptor binding domain (RBD) and nucleocapsid protein (N) IgG declined from the acute to the convalescent phase. Moreover, we demonstrate that the level of RBD-IgG is capable of correlating with SARS-CoV-2-neutralizing activities in COVID-19 serum. In summary, our findings identify the magnitude, functionality, and longevity of antibody responses in patients with COVID-19, which sheds light on the humoral immune response to COVID-19 and would be beneficial for developing vaccines.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/isolation & purification , Antibodies, Viral/blood , Antibodies, Viral/isolation & purification , COVID-19/blood , COVID-19/diagnosis , COVID-19/virology , China , Cohort Studies , Female , Humans , Immune Sera , Immunity, Humoral , Immunoglobulin G/blood , Immunoglobulin G/isolation & purification , Male , Middle Aged , Survivors , Time Factors
19.
J Investig Med ; 69(3): 704-709, 2021 03.
Article in English | MEDLINE | ID: covidwho-999288

ABSTRACT

China has experienced an outbreak of COVID-19 since December 2019. This study investigated the differences between the imported and local cases of COVID-19 in Nanyang, China. In this study, a total of 129 COVID-19 confirmed cases with a clear epidemiological history admitted to hospitals in Nanyang from January 24 to February 26, 2020 were enrolled. Patients who had a travel history to or a residence history in Wuhan or in the surrounding areas in Hubei Province within 14 days before the illness onset were assigned to the imported group (n=70), and the others were assigned to the local group (n=59). The differences in epidemiological characteristics, clinical features, laboratory and imaging results, and prognosis were compared between the 2 groups. The early diagnosed cases were mainly imported cases, and the later diagnosed ones were mainly local cases. The most common first symptom was fever; moderate fever was commonly seen in imported cases whereas low fever was commonly seen in local cases. Lymphocyte counts in the imported group were lower than those in the local group. The imported group showed more advanced and severe abnormalities in the CT scan whereas the local group showed milder pulmonary abnormalities. The proportion of severe and critically severe patients in the imported group was higher than that in the local group. In conclusion, the imported cases have more severe or critically severe patients with a higher mortality rate than the local cases.


Subject(s)
COVID-19/epidemiology , Pandemics , SARS-CoV-2 , Adult , COVID-19/mortality , COVID-19/transmission , COVID-19 Testing , China/epidemiology , Cohort Studies , Female , Hospitalization , Humans , Male , Middle Aged , Prognosis , Retrospective Studies , Severity of Illness Index , Travel
20.
Biosaf Health ; 2(4): 199-201, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-932794

ABSTRACT

Coronavirus disease 2019 (COVID-19) pandemic has spread in 220 countries/regions to wreak havoc to human beings around the world. At present, the second wave of COVID-19 has begun in many European countries. The complete control of COVID-19 is very urgent. Although China quickly brought the virus under control, there have been eight sporadic outbreaks in China since then. Both in Xinfadi of Beijing and Dalian outbreak of COVID-19, environmental swab samples related to imported cold chain food were tested nucleic acid positive for SARS-CoV-2. In this outbreak in Qingdao, we directly isolated SARS-CoV-2 from the cod outer package's surface swab samples. This is the first time worldwide, SARS-CoV-2 were isolated from the imported frozen cod outer package's surface, which showed that imported frozen food industry could import SARS-CoV-2 virus.

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