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2.
Sci Rep ; 11(1): 23223, 2021 12 01.
Article in English | MEDLINE | ID: covidwho-1553757

ABSTRACT

Low pathogenic avian influenza viruses (LPAIVs) have been widespread in poultry and wild birds throughout the world for many decades. LPAIV infections are usually asymptomatic or cause subclinical symptoms. However, the genetic reassortment of LPAIVs may generate novel viruses with increased virulence and cross-species transmission, posing potential risks to public health. To evaluate the epidemic potential and infection landscape of LPAIVs in Guangxi Province, China, we collected and analyzed throat and cloacal swab samples from chickens, ducks and geese from the live poultry markets on a regular basis from 2016 to 2019. Among the 7,567 samples, 974 (12.87%) were LPAIVs-positive, with 890 single and 84 mixed infections. Higher yearly isolation rates were observed in 2017 and 2018. Additionally, geese had the highest isolation rate, followed by ducks and chickens. Seasonally, spring had the highest isolation rate. Subtype H3, H4, H6 and H9 viruses were detected over prolonged periods, while H1 and H11 viruses were detected transiently. The predominant subtypes in chickens, ducks and geese were H9, H3, and H6, respectively. The 84 mixed infection samples contained 22 combinations. Most mixed infections involved two subtypes, with H3 + H4 as the most common combination. Our study provides important epidemiological data regarding the isolation rates, distributions of prevalent subtypes and mixed infections of LPAIVs. These results will improve our knowledge and ability to control epidemics, guide disease management strategies and provide early awareness of newly emerged AIV reassortants with pandemic potential.


Subject(s)
Influenza A virus/isolation & purification , Influenza in Birds/epidemiology , Influenza in Birds/virology , Poultry/virology , Animals , Chickens/virology , China/epidemiology , Ducks/virology , Epidemiological Monitoring , Geese/virology , Influenza A virus/genetics
3.
Viruses ; 13(11)2021 11 15.
Article in English | MEDLINE | ID: covidwho-1538547

ABSTRACT

2014 marked the first emergence of avian influenza A(H5N8) in Jeonbuk Province, South Korea, which then quickly spread worldwide. In the midst of the 2020-2021 H5N8 outbreak, it spread to domestic poultry and wild waterfowl shorebirds, leading to the first human infection in Astrakhan Oblast, Russia. Despite being clinically asymptomatic and without direct human-to-human transmission, the World Health Organization stressed the need for continued risk assessment given the nature of Influenza to reassort and generate novel strains. Given its promiscuity and easy cross to humans, the urgency to understand the mechanisms of possible species jumping to avert disastrous pandemics is increasing. Addressing the epidemiology of H5N8, its mechanisms of species jumping and its implications, mutational and reassortment libraries can potentially be built, allowing them to be tested on various models complemented with deep-sequencing and automation. With knowledge on mutational patterns, cellular pathways, drug resistance mechanisms and effects of host proteins, we can be better prepared against H5N8 and other influenza A viruses.


Subject(s)
Influenza A Virus, H5N8 Subtype/genetics , Influenza in Birds/virology , Poultry Diseases/virology , Animals , Birds/virology , Humans , Influenza in Birds/epidemiology , Pandemics/veterinary , Phylogeny , Poultry/virology , Poultry Diseases/epidemiology , Republic of Korea/epidemiology , Russia/epidemiology
5.
J Med Virol ; 93(10): 5998-6007, 2021 10.
Article in English | MEDLINE | ID: covidwho-1432442

ABSTRACT

In the context of the coronavirus disease 2019 pandemic, we investigated the epidemiological and clinical characteristics of a young patient infected by avian influenza A (H5N6) virus in Anhui Province, East China, and analyzed genomic features of the pathogen in 2020. Through the cross-sectional investigation of external environment monitoring (December 29-31, 2020), 1909 samples were collected from Fuyang City. It was found that the positive rate of H5N6 was higher than other areas obviously in Tianma poultry market, where the case appeared. In addition, dual coinfections were detected with a 0.057% polymerase chain reaction positive rate the surveillance years. The virus was the clade 2.3.4.4, which was most likely formed by genetic reassortment between H5N6 and H9N2 viruses. This study found that the evolution rates of the hemagglutinin and neuraminidase genes of the virus were higher than those of common seasonal influenza viruses. The virus was still highly pathogenic to poultry and had a preference for avian receptor binding.


Subject(s)
COVID-19/epidemiology , Influenza A virus/isolation & purification , Influenza in Birds/virology , Influenza, Human/virology , Animals , Child, Preschool , China , Female , Genome, Viral/genetics , Humans , Influenza A virus/classification , Influenza A virus/genetics , Influenza, Human/diagnosis , Mutation , Phylogeny , Poultry/virology , Reassortant Viruses/classification , Reassortant Viruses/genetics , Reassortant Viruses/isolation & purification , SARS-CoV-2 , Viral Proteins/genetics
6.
Infect Genet Evol ; 93: 104993, 2021 09.
Article in English | MEDLINE | ID: covidwho-1373190

ABSTRACT

Avian influenza virus (AIV) H7N9 that emerged in 2013 in eastern China is a novel zoonotic agent mainly circulating in poultry without clinical signs but causing severe disease with high fatality in humans in more than 5 waves. Since the emergence of highly pathogenic (HP) H7N9 variants in 2016, it has induced heavy losses in the poultry industry leading to the implementation of an intensive nationwide vaccination program at the end of wave 5 (September 2017). To characterize the ongoing evolution of H7N9 AIV, we conducted analyses of H7N9 glycoprotein genes obtained from 2013 to 2019. Bayesian analyses revealed a decreasing population size of HP H7N9 variants post wave 5. Phylogenetic topologies revealed that two novel small subclades were formed and carried several fixed amino acid mutations that were along HA and NA phylogenetic trees since wave 5. Some of the mutations were located at antigenic sites or receptor binding sites. The antigenic analysis may reveal a significant antigenic drift evaluated by hemagglutinin inhibition (HI) assay and the antigenicity of H7N9 AIV might evolute in large leaps in wave 7. Molecular simulations found that the mutations (V135T, S145P, and L226Q) around the HA receptor pocket increased the affinity to α2,3-linked sialic acid (SIA) while decreased to α2,6-linked SIA. Altered affinity may suggest that HP H7N9 variations aggravate the pathogenicity to poultry but lessen the threat to public health. Selection analyses showed that the HP H7N9 AIV experienced an increasing selection pressure since wave 5, and the national implementation of vaccination might intensify the role of natural selection during the evolution waves 6 and 7. In summary, our data provide important insights about the genetic and antigenic diversity of circulating HP H7N9 viruses from 2017 to 2019. Enhanced surveillance is urgently warranted to understand the current situation of HP H7N9 AIV.


Subject(s)
Antigenic Variation/immunology , Birds , Genetic Variation , Influenza A Virus, H7N9 Subtype/genetics , Influenza in Birds/virology , Animals , China , Influenza A Virus, H7N9 Subtype/immunology , Phylogeny
8.
Nanomedicine ; 37: 102438, 2021 10.
Article in English | MEDLINE | ID: covidwho-1306447

ABSTRACT

Highly pathogenic avian influenza viruses (HPAIVs) pose a significant threat to human health, with high mortality rates, and require effective vaccines. We showed that, harnessed with novel RNA-mediated chaperone function, hemagglutinin (HA) of H5N1 HPAIV could be displayed as an immunologically relevant conformation on self-assembled chimeric nanoparticles (cNP). A tri-partite monomeric antigen was designed including: i) an RNA-interaction domain (RID) as a docking tag for RNA to enable chaperna function (chaperna: chaperone + RNA), ii) globular head domain (gd) of HA as a target antigen, and iii) ferritin as a scaffold for 24 mer-assembly. The immunization of mice with the nanoparticles (~46 nm) induced a 25-30 fold higher neutralizing capacity of the antibody and provided cross-protection from homologous and heterologous lethal challenges. This study suggests that cNP assembly is conducive to eliciting antibodies against the conserved region in HA, providing potent and broad protective efficacy.


Subject(s)
Hemagglutinin Glycoproteins, Influenza Virus/immunology , Influenza A Virus, H5N1 Subtype/drug effects , Influenza Vaccines/immunology , Influenza in Birds/immunology , RNA/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/immunology , Antibodies, Viral/therapeutic use , Birds/virology , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Hemagglutinin Glycoproteins, Influenza Virus/therapeutic use , Humans , Influenza A Virus, H5N1 Subtype/immunology , Influenza A Virus, H5N1 Subtype/pathogenicity , Influenza Vaccines/chemistry , Influenza Vaccines/therapeutic use , Influenza in Birds/prevention & control , Influenza in Birds/virology , Mice , Nanoparticles/chemistry , Nanoparticles/therapeutic use , Pandemics , RNA/genetics , RNA/therapeutic use
9.
J Med Virol ; 93(10): 5998-6007, 2021 10.
Article in English | MEDLINE | ID: covidwho-1298504

ABSTRACT

In the context of the coronavirus disease 2019 pandemic, we investigated the epidemiological and clinical characteristics of a young patient infected by avian influenza A (H5N6) virus in Anhui Province, East China, and analyzed genomic features of the pathogen in 2020. Through the cross-sectional investigation of external environment monitoring (December 29-31, 2020), 1909 samples were collected from Fuyang City. It was found that the positive rate of H5N6 was higher than other areas obviously in Tianma poultry market, where the case appeared. In addition, dual coinfections were detected with a 0.057% polymerase chain reaction positive rate the surveillance years. The virus was the clade 2.3.4.4, which was most likely formed by genetic reassortment between H5N6 and H9N2 viruses. This study found that the evolution rates of the hemagglutinin and neuraminidase genes of the virus were higher than those of common seasonal influenza viruses. The virus was still highly pathogenic to poultry and had a preference for avian receptor binding.


Subject(s)
COVID-19/epidemiology , Influenza A virus/isolation & purification , Influenza in Birds/virology , Influenza, Human/virology , Animals , Child, Preschool , China , Female , Genome, Viral/genetics , Humans , Influenza A virus/classification , Influenza A virus/genetics , Influenza, Human/diagnosis , Mutation , Phylogeny , Poultry/virology , Reassortant Viruses/classification , Reassortant Viruses/genetics , Reassortant Viruses/isolation & purification , SARS-CoV-2 , Viral Proteins/genetics
10.
Life Sci Alliance ; 4(6)2021 06.
Article in English | MEDLINE | ID: covidwho-1170604

ABSTRACT

Infection of certain influenza viruses is triggered when its HA is cleaved by host cell proteases such as proprotein convertases and type II transmembrane serine proteases (TTSP). HA with a monobasic motif is cleaved by trypsin-like proteases, including TMPRSS2 and HAT, whereas the multibasic motif found in high pathogenicity avian influenza HA is cleaved by furin, PC5/6, or MSPL. MSPL belongs to the TMPRSS family and preferentially cleaves [R/K]-K-K-R↓ sequences. Here, we solved the crystal structure of the extracellular region of human MSPL in complex with an irreversible substrate-analog inhibitor. The structure revealed three domains clustered around the C-terminal α-helix of the SPD. The inhibitor structure and its putative model show that the P1-Arg inserts into the S1 pocket, whereas the P2-Lys and P4-Arg interacts with the Asp/Glu-rich 99-loop that is unique to MSPL. Based on the structure of MSPL, we also constructed a homology model of TMPRSS2, which is essential for the activation of the SARS-CoV-2 spike protein and infection. The model may provide the structural insight for the drug development for COVID-19.


Subject(s)
Influenza in Birds/virology , Membrane Proteins/chemistry , Orthomyxoviridae/pathogenicity , Serine Endopeptidases/chemistry , Animals , Birds , Crystallography, X-Ray , Humans , Protein Conformation
11.
Trends Microbiol ; 29(7): 573-581, 2021 07.
Article in English | MEDLINE | ID: covidwho-1130313

ABSTRACT

Emerging zoonotic diseases exert a significant burden on human health and have considerable socioeconomic impact worldwide. In Asia, live animals as well as animal products are commonly sold in informal markets. The interaction of humans, live domestic animals for sale, food products, and wild and scavenging animals, creates a risk for emerging infectious diseases. Such markets have been in the spotlight as sources of zoonotic viruses, for example, avian influenza viruses and coronaviruses, Here, we bring data together on the global impact of live and wet markets on the emergence of zoonotic diseases. We discuss how benefits can be maximized and risks minimized and conclude that current regulations should be implemented or revised, to mitigate the risk of new diseases emerging in the future.


Subject(s)
Commerce/standards , Communicable Diseases, Emerging/etiology , Food , Orthomyxoviridae Infections/transmission , Zoonoses/transmission , Animals , Asia , Birds/virology , COVID-19/transmission , COVID-19/virology , Commerce/legislation & jurisprudence , Commerce/methods , Communicable Diseases, Emerging/prevention & control , Communicable Diseases, Emerging/virology , Crowding , Humans , Influenza in Birds/transmission , Influenza in Birds/virology , Influenza, Human/virology , Orthomyxoviridae Infections/virology , Zoonoses/classification , Zoonoses/virology
12.
J Biol Chem ; 296: 100017, 2021.
Article in English | MEDLINE | ID: covidwho-910220

ABSTRACT

Through annual epidemics and global pandemics, influenza A viruses (IAVs) remain a significant threat to human health as the leading cause of severe respiratory disease. Within the last century, four global pandemics have resulted from the introduction of novel IAVs into humans, with components of each originating from avian viruses. IAVs infect many avian species wherein they maintain a diverse natural reservoir, posing a risk to humans through the occasional emergence of novel strains with enhanced zoonotic potential. One natural barrier for transmission of avian IAVs into humans is the specificity of the receptor-binding protein, hemagglutinin (HA), which recognizes sialic-acid-containing glycans on host cells. HAs from human IAVs exhibit "human-type" receptor specificity, binding exclusively to glycans on cells lining the human airway where terminal sialic acids are attached in the α2-6 configuration (NeuAcα2-6Gal). In contrast, HAs from avian viruses exhibit specificity for "avian-type" α2-3-linked (NeuAcα2-3Gal) receptors and thus require adaptive mutations to bind human-type receptors. Since all human IAV pandemics can be traced to avian origins, there remains ever-present concern over emerging IAVs with human-adaptive potential that might lead to the next pandemic. This concern has been brought into focus through emergence of SARS-CoV-2, aligning both scientific and public attention to the threat of novel respiratory viruses from animal sources. In this review, we summarize receptor-binding adaptations underlying the emergence of all prior IAV pandemics in humans, maintenance and evolution of human-type receptor specificity in subsequent seasonal IAVs, and potential for future human-type receptor adaptation in novel avian HAs.


Subject(s)
Hemagglutinin Glycoproteins, Influenza Virus/metabolism , Influenza A virus/metabolism , Influenza in Birds/epidemiology , Influenza, Human/epidemiology , Pandemics , Polysaccharides/chemistry , Receptors, Virus/metabolism , Adaptation, Physiological , Animals , Binding Sites , Biological Coevolution , Birds/virology , Hemagglutinin Glycoproteins, Influenza Virus/chemistry , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Humans , Influenza A virus/chemistry , Influenza A virus/genetics , Influenza in Birds/transmission , Influenza in Birds/virology , Influenza, Human/transmission , Influenza, Human/virology , Models, Molecular , Polysaccharides/metabolism , Protein Binding , Receptors, Virus/chemistry , Receptors, Virus/genetics , Respiratory System/virology , Sialic Acids/chemistry , Sialic Acids/metabolism , Species Specificity
13.
Sci Rep ; 10(1): 16631, 2020 10 06.
Article in English | MEDLINE | ID: covidwho-834914

ABSTRACT

The aim of this study was to test in vitro the ability of a mixture of citrus extract, maltodextrin, sodium chloride, lactic acid and citric acid (AuraShield L) to inhibit the virulence of infectious bronchitis, Newcastle disease, avian influenza, porcine reproductive and respiratory syndrome (PRRS) and bovine coronavirus viruses. Secondly, in vivo, we have investigated its efficacy against infectious bronchitis using a broiler infection model. In vitro, these antimicrobials had expressed antiviral activity against all five viruses through all phases of the infection process of the host cells. In vivo, the antimicrobial mixture reduced the virus load in the tracheal and lung tissue and significantly reduced the clinical signs of infection and the mortality rate in the experimental group E2 receiving AuraShield L. All these effects were accompanied by a significant reduction in the levels of pro-inflammatory cytokines and an increase in IgA levels and short chain fatty acids (SCFAs) in both trachea and lungs. Our study demonstrated that mixtures of natural antimicrobials, such AuraShield L, can prevent in vitro viral infection of cell cultures. Secondly, in vivo, the efficiency of vaccination was improved by preventing secondary viral infections through a mechanism involving significant increases in SCFA production and increased IgA levels. As a consequence the clinical signs of secondary infections were significantly reduced resulting in recovered production performance and lower mortality rates in the experimental group E2.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus Infections/drug therapy , Coronavirus, Bovine/drug effects , Epithelial Cells/drug effects , Infectious bronchitis virus/drug effects , Influenza A Virus, H9N2 Subtype/drug effects , Newcastle disease virus/drug effects , Porcine respiratory and reproductive syndrome virus/drug effects , Poultry Diseases/drug therapy , Animals , Cell Line , Chick Embryo , Chickens , Coronavirus Infections/virology , Disease Models, Animal , Epithelial Cells/virology , Humans , Influenza in Birds/metabolism , Influenza in Birds/virology , Influenza, Human/metabolism , Influenza, Human/virology , Newcastle Disease/metabolism , Newcastle Disease/virology , Porcine Reproductive and Respiratory Syndrome/metabolism , Porcine Reproductive and Respiratory Syndrome/virology , Poultry Diseases/virology , Swine
14.
Avian Pathol ; 49(1): 21-28, 2020 Feb.
Article in English | MEDLINE | ID: covidwho-822641

ABSTRACT

Since the emergence of low pathogenic avian influenza (LPAI) H9N2 viruses in Morocco in 2016, severe respiratory problems have been encountered in the field. Infectious bronchitis virus (IBV) is often detected together with H9N2, suggesting disease exacerbation in cases of co-infections. This hypothesis was therefore tested and confirmed in laboratory conditions using specific-pathogen-free chickens. Most common field vaccine programmes were then tested to compare their efficacies against these two co-infecting agents. IBV γCoV/chicken/Morocco/I38/2014 (Mor-IT02) and LPAI virus A/chicken/Morocco/SF1/2016 (Mor-H9N2) were thus inoculated to commercial chickens. We showed that vaccination with two heterologous IBV vaccines (H120 at day one and 4/91 at day 14 of age) reduced the severity of clinical signs as well as macroscopic lesions after simultaneous experimental challenge. In addition, LPAI H9N2 vaccination was more efficient at day 7 than at day 1 in limiting disease post simultaneous challenge.RESEARCH HIGHLIGHTS Simultaneous challenge with IBV and AIV H9N2 induced higher pathogenicity in SPF birds than inoculation with IBV or AIV H9N2 alone.Recommended vaccination programme in commercial broilers to counter Mor-IT02 IBV and LPAIV H9N2 simultaneous infections: IB live vaccine H120 (d1), AIV H9N2 inactivated vaccine (d7), IB live vaccine 4-91 (d14).


Subject(s)
Chickens , Coinfection/veterinary , Coronavirus Infections/veterinary , Infectious bronchitis virus , Influenza A Virus, H9N2 Subtype , Influenza in Birds/virology , Animals , Antibodies, Viral/blood , Chick Embryo , Coinfection/prevention & control , Coinfection/virology , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Influenza in Birds/prevention & control , Lung/pathology , Morocco , Oropharynx/virology , Pilot Projects , Poultry Diseases/prevention & control , Poultry Diseases/virology , RNA, Viral/chemistry , RNA, Viral/isolation & purification , Real-Time Polymerase Chain Reaction/veterinary , Specific Pathogen-Free Organisms , Trachea/pathology , Vaccination/veterinary , Vaccines, Attenuated , Viral Vaccines , Virus Shedding
15.
Cytokine ; 127: 154961, 2020 03.
Article in English | MEDLINE | ID: covidwho-822511

ABSTRACT

Some of the respiratory viral infections in chickens pose a significant threat to the poultry industry and public health. In response to viral infections, host innate responses provide the first line of defense against viruses, which often act even before the establishment of the infection. Host cells sense the presence of viral components through germinal encoded pattern recognition receptors (PRRs). The engagement of PRRs with pathogen-associated molecular patterns leads to the induction of pro-inflammatory and interferon productions. Induced antiviral responses play a critical role in the outcome of the infections. In order to improve current strategies for control of viral infections or to advance new strategies aimed against viral infections, a deep understanding of host-virus interaction and induction of antiviral responses is required. In this review, we summarized recent progress in understanding innate antiviral responses in chickens with a focus on the avian influenza virus and infectious bronchitis virus.


Subject(s)
Antiviral Agents/pharmacology , Chickens/virology , Coronavirus Infections/drug therapy , Infectious bronchitis virus/drug effects , Influenza A virus/drug effects , Influenza in Birds/drug therapy , Respiratory Tract Infections/drug therapy , Animals , Coronavirus Infections/virology , Humans , Influenza in Birds/virology , Respiratory Tract Infections/virology
16.
Front Immunol ; 11: 552909, 2020.
Article in English | MEDLINE | ID: covidwho-803900

ABSTRACT

The 2019 novel coronavirus (SARS-CoV-2) pandemic has caused a global health emergency. The outbreak of this virus has raised a number of questions: What is SARS-CoV-2? How transmissible is SARS-CoV-2? How severely affected are patients infected with SARS-CoV-2? What are the risk factors for viral infection? What are the differences between this novel coronavirus and other coronaviruses? To answer these questions, we performed a comparative study of four pathogenic viruses that primarily attack the respiratory system and may cause death, namely, SARS-CoV-2, severe acute respiratory syndrome (SARS-CoV), Middle East respiratory syndrome (MERS-CoV), and influenza A viruses (H1N1 and H3N2 strains). This comparative study provides a critical evaluation of the origin, genomic features, transmission, and pathogenicity of these viruses. Because the coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 is ongoing, this evaluation may inform public health administrators and medical experts to aid in curbing the pandemic's progression.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/epidemiology , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H3N2 Subtype/genetics , Influenza, Human/epidemiology , Middle East Respiratory Syndrome Coronavirus/genetics , Pneumonia, Viral/epidemiology , SARS Virus/genetics , Severe Acute Respiratory Syndrome/epidemiology , Animals , Betacoronavirus/pathogenicity , Birds/virology , COVID-19 , Coronavirus Infections/transmission , Coronavirus Infections/virology , Genome, Viral , Humans , Influenza A Virus, H1N1 Subtype/pathogenicity , Influenza A Virus, H3N2 Subtype/pathogenicity , Influenza in Birds/epidemiology , Influenza in Birds/transmission , Influenza in Birds/virology , Influenza, Human/transmission , Influenza, Human/virology , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Pandemics , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , SARS Virus/pathogenicity , SARS-CoV-2 , Severe Acute Respiratory Syndrome/transmission , Severe Acute Respiratory Syndrome/virology , Virulence/immunology
17.
Avian Pathol ; 49(6): 529-531, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-726975

ABSTRACT

COVID-19 should be a "call to arms" for the poultry industry to reassess containment of the H9N2 subtype of low pathogenicity avian influenza viruses. Strains of this virus are a human pandemic threat and a severe economic burden on poultry production. Over the past 20 years they have spread throughout Asia, Africa, Middle East and parts of Europe. As a global industry, a critical need is to re-imagine production and marketing chains, especially in low and middle-income countries, where the structure of much of the industry facilitates virus transmission, especially, but not only, in improperly managed live poultry markets and related value chains. Better, appropriately matched vaccines are needed to support this process but such vaccines cannot, alone, overcome the existing defects in biosecurity, including high farm densities. None of this will occur unless the threat posed by this virus to global health security is recognized.


Subject(s)
Betacoronavirus , Coronavirus Infections/epidemiology , Influenza A Virus, H9N2 Subtype , Influenza in Birds/virology , Influenza, Human/virology , Pneumonia, Viral/epidemiology , Animals , Birds , COVID-19 , Coronavirus Infections/virology , Global Health , Humans , Influenza in Birds/epidemiology , Influenza in Birds/prevention & control , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Pandemics , Pneumonia, Viral/virology , Poultry/virology , SARS-CoV-2
18.
Biomed J ; 43(4): 375-387, 2020 08.
Article in English | MEDLINE | ID: covidwho-549109

ABSTRACT

BACKGROUND: Highly pathogenic emerging and re-emerging viruses continuously threaten lives worldwide. In order to provide prophylactic prevention from the emerging and re-emerging viruses, vaccine is suggested as the most efficient way to prevent individuals from the threat of viral infection. Nonetheless, the highly pathogenic viruses need to be handled in a high level of biosafety containment, which hinders vaccine development. To shorten the timeframe of vaccine development, the pseudovirus system has been widely applied to examine vaccine efficacy or immunogenicity in the emerging and re-emerging viruses. METHODS: We developed pseudovirus systems for emerging SARS coronavirus 2 (SARS-CoV-2) and re-emerging avian influenza virus H5 subtypes which can be handled in the biosafety level 2 facility. Through the generated pseudovirus of SARS-CoV-2 and avian influenza virus H5 subtypes, we successfully established a neutralization assay to quantify the neutralizing activity of antisera against the viruses. RESULTS: The result of re-emerging avian influenza virus H5Nx pseudoviruses provided valuable information for antigenic evolution and immunogenicity analysis in vaccine candidate selection. Together, our study assessed the potency of pseudovirus systems in vaccine efficacy, antigenic analysis, and immunogenicity in the vaccine development of emerging and re-emerging viruses. CONCLUSION: Instead of handling live highly pathogenic viruses in a high biosafety level facility, using pseudovirus systems would speed up the process of vaccine development to provide community protection against emerging and re-emerging viral diseases with high pathogenicity.


Subject(s)
Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Influenza in Birds/drug therapy , Pneumonia, Viral/drug therapy , Viral Vaccines , Animals , Betacoronavirus/immunology , Betacoronavirus/pathogenicity , Birds , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/prevention & control , Drug Development/methods , Humans , Influenza A virus/immunology , Influenza in Birds/prevention & control , Influenza in Birds/virology , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , SARS-CoV-2
19.
BMC Infect Dis ; 20(1): 369, 2020 May 24.
Article in English | MEDLINE | ID: covidwho-343360

ABSTRACT

BACKGROUND: Previous studies have proven that the closure of live poultry markets (LPMs) was an effective intervention to reduce human risk of avian influenza A (H7N9) infection, but evidence is limited on the impact of scale and duration of LPMs closure on the transmission of H7N9. METHOD: Five cities (i.e., Shanghai, Suzhou, Shenzhen, Guangzhou and Hangzhou) with the largest number of H7N9 cases in mainland China from 2013 to 2017 were selected in this study. Data on laboratory-confirmed H7N9 human cases in those five cities were obtained from the Chinese National Influenza Centre. The detailed information of LPMs closure (i.e., area and duration) was obtained from the Ministry of Agriculture. We used a generalized linear model with a Poisson link to estimate the effect of LPMs closure, reported as relative risk reduction (RRR). We used classification and regression trees (CARTs) model to select and quantify the dominant factor of H7N9 infection. RESULTS: All five cities implemented the LPMs closure, and the risk of H7N9 infection decreased significantly after LPMs closure with RRR ranging from 0.80 to 0.93. Respectively, a long-term LPMs closure for 10-13 weeks elicited a sustained and highly significant risk reduction of H7N9 infection (RRR = 0.98). Short-time LPMs closure with 2 weeks in every epidemic did not reduce the risk of H7N9 infection (p > 0.05). Partially closed LPMs in some suburbs contributed only 35% for reduction rate (RRR = 0.35). Shenzhen implemented partial closure for first 3 epidemics (p > 0.05) and all closure in the latest 2 epidemic waves (RRR = 0.64). CONCLUSION: Our findings suggest that LPMs all closure in whole city can be a highly effective measure comparing with partial closure (i.e. only urban closure, suburb and rural remain open). Extend the duration of closure and consider permanently closing the LPMs will help improve the control effect. The effect of LPMs closure seems greater than that of meteorology on H7N9 transmission.


Subject(s)
Epidemics/prevention & control , Influenza A Virus, H7N9 Subtype , Influenza in Birds/epidemiology , Influenza in Birds/transmission , Influenza, Human/epidemiology , Poultry/virology , Animals , China/epidemiology , Cities/epidemiology , Humans , Humidity , Incidence , Influenza in Birds/virology , Influenza, Human/virology , Linear Models , Poisson Distribution , Risk Factors , Temperature , Urban Population
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