16 results on '"Yifei Xu"'
Search Results
2. Novel highly pathogenic avian influenza A(H5N6) virus in the Netherlands, December 2017
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Yifei Xu
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0301 basic medicine ,Microbiology (medical) ,Letter ,Epidemiology ,Highly pathogenic ,Reassortment ,lcsh:Medicine ,Biology ,medicine.disease_cause ,influenza virus ,lcsh:Infectious and parasitic diseases ,Birds ,respiratory infections ,03 medical and health sciences ,medicine ,Animals ,viruses ,lcsh:RC109-216 ,highly pathogenic avian influenza ,clade 2.3.4.4 H5Nx ,Letters to the Editor ,Poultry Diseases ,Netherlands ,Novel Highly Pathogenic Avian Influenza A(H5N6) Virus in the Netherlands ,the Netherlands ,lcsh:R ,Virology ,H5N6 ,Influenza A virus subtype H5N1 ,zoonoses ,030104 developmental biology ,Infectious Diseases ,Influenza A virus ,Influenza in Birds ,reassortment ,influenza - Published
- 2019
3. A quantitative RT-PCR assay for rapid detection of Eurasian-lineage H10 subtype influenza A virus
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Thomas J. DeLiberto, Xiu-Feng Wan, Yi Zhang, Hailiang Sun, Yifei Xu, Lanny W. Pace, John A. Baroch, Jianli Xue, Guoliang Hu, and Elizabeth Bailey
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0301 basic medicine ,medicine.medical_specialty ,Lineage (genetic) ,030106 microbiology ,Immunology ,Biology ,medicine.disease_cause ,Virology ,Rapid detection ,Article ,03 medical and health sciences ,030104 developmental biology ,Medical microbiology ,Real-time polymerase chain reaction ,medicine ,Influenza A virus ,Molecular Medicine - Abstract
Quantitative RT-PCR (qRT-PCR) has been commonly used for IAV detection in influenza surveillance and disease diagnosis because of its high sensitivity, specificity, and high throughput. A number of HA subtype specific qRT-PCR methods have been developed, including H5, H7, and H9 (Monne et al., 2008). However, there is still lack of a specific qRT-PCR method for detecting the emerging H10N8 IAVs. In this study, a Eurasian-lineage H10 specific qRT-PCR is developed and validated.
- Published
- 2016
4. Dynamics of virus shedding and antibody responses in influenza A virus-infected feral swine
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Brandon S. Schmit, Jim Cooley, Yifei Xu, Li-Ping Long, Katie C. Hanson-Dorr, Xui-Feng Wan, Fred L. Cunningham, Richard G. Jarman, Hailiang Sun, Tao Li, Paul B. Fioranelli, Kerri Pedersen, Mark W. Lutman, Jillian Harris, John A. Baroch, Xiaoxu Lin, and Thomas J. DeLiberto
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Swine Diseases ,biology ,Swine ,Inoculation ,Influenza A Virus, H3N2 Subtype ,animal diseases ,Animals, Wild ,Context (language use) ,Antibodies, Viral ,medicine.disease_cause ,Virology ,Standard ,Virus ,Virus Shedding ,Nucleoprotein ,Serology ,Orthomyxoviridae Infections ,biology.protein ,Influenza A virus ,medicine ,Animals ,Antibody ,Viral shedding - Abstract
Given their free-ranging habits, feral swine could serve as reservoirs or spatially dynamic ‘mixing vessels’ for influenza A virus (IAV). To better understand virus shedding patterns and antibody response dynamics in the context of IAV surveillance amongst feral swine, we used IAV of feral swine origin to perform infection experiments. The virus was highly infectious and transmissible in feral swine, and virus shedding patterns and antibody response dynamics were similar to those in domestic swine. In the virus-inoculated and sentinel groups, virus shedding lasted ≤ 6 and ≤ 9 days, respectively. Antibody titres in inoculated swine peaked at 1 : 840 on day 11 post-inoculation (p.i.), remained there until 21 days p.i. and dropped to
- Published
- 2015
5. Identification of the source of A (H10N8) virus causing human infection
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Li-Ping Long, Richard J. Webby, Sook-San Wong, Ming Liao, Yifei Xu, Yibo Zong, Guangfu Deng, Jianli Xue, Xiu-Feng Wan, Yulong Zhao, Xiaoshan Fu, Hailiang Sun, Nan Zhao, Huabin Cao, Guoliang Hu, George F. Gao, Qi Wang, Hongyan Liu, Jing Zhu, Brigitte E. Martin, and Feng Wen
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Microbiology (medical) ,China ,viruses ,Biology ,medicine.disease_cause ,Microbiology ,H5N1 genetic structure ,Poultry ,Article ,Virus ,Influenza A Virus, H10N8 Subtype ,Influenza, Human ,Veterinary virology ,Pandemic ,Genetics ,medicine ,Influenza A virus ,Animals ,Humans ,Molecular Biology ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Virology ,Influenza A virus subtype H5N1 ,Infectious Diseases ,Influenza in Birds ,Human mortality from H5N1 ,Transmission and infection of H5N1 - Abstract
A novel H10N8 influenza A virus has been detected in three humans in China since December 2013. Although this virus was hypothesized to be a novel reassortant among influenza viruses from wild birds and domestic poultry, its evolutionary path leading to human infection is unknown. Sporadic surveillance at the live poultry market (LPM) suspected to be the source of infection for the first H10N8 patient has shown a gradual increase in influenza virus prevalence culminating with a predominance of H10N8 viruses. Influenza viruses detected in the LPM up to 8 months prior to human infection contributed genetic components to the zoonotic virus. These H10N8 viruses have continued to evolve within this LPM subsequent to the human infection, and continuous assessments of these H10N8 viruses will be necessary. Serological surveillance showed that the virus appears to have been present throughout the LPM system in Nanchang, China. Reduction of the influenza virus burden in LPMs is essential in preventing future emergence of novel influenza viruses with zoonotic and pandemic potential.
- Published
- 2015
6. Zoonotic Risk, Pathogenesis, and Transmission of Avian-Origin H3N2 Canine Influenza Virus
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Ratanaporn Tangwangvivat, Xiaoxu Lin, Jim Cooley, Yifei Xu, Larry A. Hanson, Richard G. Jarman, Guohua Yang, Xiu-Feng Wan, Hailiang Sun, Tao Li, Kaitlyn Waters, Lucy Senter, Richard J. Webby, Feng Wen, Daniel Shyu, and Sherry Blackmon
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0301 basic medicine ,viruses ,Canine influenza ,Immunology ,Reassortment ,Population ,Equine influenza ,Biology ,medicine.disease_cause ,Microbiology ,Virus ,Madin Darby Canine Kidney Cells ,03 medical and health sciences ,Mice ,Viral Proteins ,Dogs ,Influenza A Virus, H1N1 Subtype ,Orthomyxoviridae Infections ,Risk Factors ,Virology ,Zoonoses ,Reassortant Viruses ,medicine ,Influenza A virus ,Animals ,Dog Diseases ,education ,Lung ,education.field_of_study ,Mice, Inbred BALB C ,Influenza A Virus, H3N2 Subtype ,Ferrets ,virus diseases ,Influenza A virus subtype H5N1 ,030104 developmental biology ,Insect Science ,Female ,Erratum - Abstract
Two subtypes of influenza A virus (IAV), avian-origin canine influenza virus (CIV) H3N2 (CIV-H3N2) and equine-origin CIV H3N8 (CIV-H3N8), are enzootic in the canine population. Dogs have been demonstrated to seroconvert in response to diverse IAVs, and naturally occurring reassortants of CIV-H3N2 and the 2009 H1N1 pandemic virus (pdmH1N1) have been isolated. We conducted a thorough phenotypic evaluation of CIV-H3N2 in order to assess its threat to human health. Using ferret-generated antiserum, we determined that CIV-H3N2 is antigenically distinct from contemporary human H3N2 IAVs, suggesting that there may be minimal herd immunity in humans. We assessed the public health risk of CIV-H3N2 × pandemic H1N1 (pdmH1N1) reassortants by characterizing their in vitro genetic compatibility and in vivo pathogenicity and transmissibility. Using a luciferase minigenome assay, we quantified the polymerase activity of all possible 16 ribonucleoprotein (RNP) complexes (PB2, PB1, PA, NP) between CIV-H3N2 and pdmH1N1, identifying some combinations that were more active than either parental virus complex. Using reverse genetics and fixing the CIV-H3N2 hemagglutinin (HA), we found that 51 of the 127 possible reassortant viruses were viable and able to be rescued. Nineteen of these reassortant viruses had high-growth phenotypes in vitro , and 13 of these replicated in mouse lungs. A single reassortant with the NP and HA gene segments from CIV-H3N2 was selected for characterization in ferrets. The reassortant was efficiently transmitted by contact but not by the airborne route and was pathogenic in ferrets. Our results suggest that CIV-H3N2 reassortants may pose a moderate risk to public health and that the canine host should be monitored for emerging IAVs. IMPORTANCE IAV pandemics are caused by the introduction of novel viruses that are capable of efficient and sustained transmission into a human population with limited herd immunity. Dogs are a a potential mixing vessel for avian and mammalian IAVs and represent a human health concern due to their susceptibility to infection, large global population, and close physical contact with humans. Our results suggest that humans are likely to have limited preexisting immunity to CIV-H3N2 and that CIV-H3N2 × pdmH1N1 reassortants have moderate genetic compatibility and are transmissible by direct contact in ferrets. Our study contributes to the increasing evidence that surveillance of the canine population for IAVs is an important component of pandemic preparedness.
- Published
- 2017
7. Influenza A Subtype H3 Viruses in Feral Swine, United States, 2011–2012
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Fred L. Cunningham, Brandon S. Schmit, Mark W. Lutman, Kerri Pedersen, Thomas J. DeLiberto, Xiu-Feng Wan, John A. Baroch, Yifei Xu, Andrew S. Bowman, Zhixin Feng, and Li-Ping Long
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Male ,Microbiology (medical) ,Serotype ,medicine.medical_specialty ,Swine ,Epidemiology ,animal diseases ,viruses ,Prevalence ,lcsh:Medicine ,Biology ,medicine.disease_cause ,History, 21st Century ,lcsh:Infectious and parasitic diseases ,Serology ,swine influenza virus ,Orthomyxoviridae Infections ,feral swine ,Public health surveillance ,Influenza, Human ,serologic assay ,medicine ,Influenza A virus ,Animals ,Humans ,influenza A virus ,Seroprevalence ,Public Health Surveillance ,lcsh:RC109-216 ,Serotyping ,seropositive ,Swine Diseases ,Geography ,H3N2v ,business.industry ,Influenza A Virus, H3N2 Subtype ,Public health ,lcsh:R ,Dispatch ,Virology ,United States ,H3 ,Infectious Diseases ,Female ,Livestock ,business - Abstract
To determine whether, and to what extent, influenza A subtype H3 viruses were present in feral swine in the United States, we conducted serologic and virologic surveillance during October 2011–September 2012. These animals were periodically exposed to and infected with A(H3N2) viruses, suggesting they may threaten human and animal health.
- Published
- 2014
8. Low-Pathogenic Influenza A Viruses in North American Diving Ducks Contribute to the Emergence of a Novel Highly Pathogenic Influenza A(H7N8) Virus
- Author
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Mia Kim Torchetti, Andrew M. Ramey, Richard J. Webby, Thomas J. DeLiberto, Xiu-Feng Wan, David E. Stallknecht, Andrew B. Reeves, Yifei Xu, Jacqueline M. Nolting, Mary Lea Killian, Andrew S. Bowman, and Scott Krauss
- Subjects
0301 basic medicine ,Turkeys ,viruses ,030106 microbiology ,Immunology ,Reassortment ,Animals, Wild ,Genome, Viral ,Biology ,medicine.disease_cause ,Microbiology ,H5N1 genetic structure ,Virus ,Disease Outbreaks ,Evolution, Molecular ,03 medical and health sciences ,Virology ,Flyway ,medicine ,Animals ,Phylogeny ,Poultry Diseases ,Recombination, Genetic ,Base Sequence ,Transmission (medicine) ,Sequence Analysis, RNA ,Outbreak ,virus diseases ,biology.organism_classification ,Influenza A virus subtype H5N1 ,030104 developmental biology ,Diving duck ,Ducks ,Genetic Diversity and Evolution ,Influenza A virus ,Insect Science ,Influenza in Birds ,human activities - Abstract
Introductions of low-pathogenic avian influenza (LPAI) viruses of subtypes H5 and H7 into poultry from wild birds have the potential to mutate to highly pathogenic avian influenza (HPAI) viruses, but such viruses' origins are often unclear. In January 2016, a novel H7N8 HPAI virus caused an outbreak in turkeys in Indiana, USA. To determine the virus's origin, we sequenced the genomes of 441 wild-bird origin influenza A viruses (IAVs) from North America and subjected them to evolutionary analyses. The results showed that the H7N8 LPAI virus most likely circulated among diving ducks in the Mississippi flyway during autumn 2015 and was subsequently introduced to Indiana turkeys, in which it evolved high pathogenicity. Preceding the outbreak, an isolate with six gene segments (PB2, PB1, PA, HA, NA, and NS) sharing >99% sequence identity with those of H7N8 turkey isolates was recovered from a diving duck sampled in Kentucky, USA. H4N8 IAVs from other diving ducks possessed five H7N8-like gene segments (PB2, PB1, NA, MP, and NS; >98% sequence identity). Our findings suggest that viral gene constellations circulating among diving ducks can contribute to the emergence of IAVs that affect poultry. Therefore, diving ducks may serve an important and understudied role in the maintenance, diversification, and transmission of IAVs in the wild-bird reservoir. IMPORTANCE In January 2016, a novel H7N8 HPAI virus caused a disease outbreak in turkeys in Indiana, USA. To determine the origin of this virus, we sequenced and analyzed 441 wild-bird origin influenza virus strains isolated from wild birds inhabiting North America. We found that the H7N8 LPAI virus most likely circulated among diving ducks in the Mississippi flyway during autumn 2015 and was subsequently introduced to Indiana turkeys, in which it evolved high pathogenicity. Our results suggest that viral gene constellations circulating among diving ducks can contribute to the emergence of IAVs that affect poultry. Therefore, diving ducks may play an important and understudied role in the maintenance, diversification, and transmission of IAVs in the wild-bird reservoir. Our study also highlights the importance of a coordinated, systematic, and collaborative surveillance for IAVs in both poultry and wild-bird populations.
- Published
- 2016
9. Mutation from arginine to lysine at the position 189 of hemagglutinin contributes to the antigenic drift in H3N2 swine influenza viruses
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Fred L. Cunningham, Jianqiang Ye, Yifei Xu, Jillian Harris, Andrew S. Bowman, Xiu-Feng Wan, Richard D. Slemons, Kyoung-Jin Yoon, Hailiang Sun, and Carol J. Cardona
- Subjects
Antigenic drift ,Swine ,Orthomyxoviridae ,Mutation, Missense ,Hemagglutinin (influenza) ,Hemagglutinin Glycoproteins, Influenza Virus ,R189K ,Cross Reactions ,medicine.disease_cause ,Antibodies, Viral ,Arginine ,Epitope ,Article ,Virology ,Reassortant Viruses ,Influenza A virus ,medicine ,Animals ,Humans ,Serological assay ,Antigens, Viral ,biology ,H3N2v ,Influenza A Virus, H3N2 Subtype ,Lysine ,Genetic Drift ,Ferrets ,Antigenic shift ,Antigenic variant ,H3N2 ,biology.organism_classification ,Reverse Genetics ,United States ,Mutation (genetic algorithm) ,biology.protein ,Antigenic cartography - Abstract
Two distinct antigenic clusters were previously identified among the H3N2 swine influenza A viruses (IAVs) and were designated H3N2SIV-alpha and H3N2SIV-beta ( Feng et al., 2013. Journal of Virology 87 (13), 7655–7667 ). A consistent mutation was observed at the position 189 of hemagglutinin (R189K) between H3N2SIV-alpha and H3N2SIV-beta fair isolates. To evaluate the contribution of R189K mutation to the antigenic drift from H3N2SIV-alpha to H3N2SIV-beta, four reassortant viruses with 189R or 189K were generated. The antigenic cartography demonstrated that the R189K mutation in the hemagglutinin of H3N2 IAV contributed to the antigenic drift, separating these viruses into H3N2SIV-alpha to H3N2SIV-beta. This R189K mutation was also found to contribute to the cross-reaction with several ferret sera raised against historical human IAVs with hemagglutinin carrying 189K. This study suggests that the R189K mutation plays a vital role in the antigenicity of swine and human H3N2 IAVs and identification of this antigenic determinant will help us rapidly identify antigenic variants in influenza surveillance.
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- 2013
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10. Limited Antigenic Diversity in Contemporary H7 Avian-Origin Influenza A Viruses from North America
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Li-Ping Long, Richard G. Jarman, John A. Baroch, Hui Wang, Tao Li, Thomas J. DeLiberto, Xiu-Feng Wan, Elizabeth Bailey, Erica Spackman, Xiaoxu Lin, Fred L. Cunningham, and Yifei Xu
- Subjects
0301 basic medicine ,animal diseases ,030106 microbiology ,Hemagglutinin (influenza) ,Hemagglutinin Glycoproteins, Influenza Virus ,Chick Embryo ,Culling ,Biology ,medicine.disease_cause ,Article ,Influenza A Virus, H7N3 Subtype ,03 medical and health sciences ,Antigenic Diversity ,Genotype ,Influenza A virus ,medicine ,Antigenic variation ,Waterfowl ,Animals ,Humans ,Antigens, Viral ,Gene ,Multidisciplinary ,virus diseases ,biology.organism_classification ,Antigenic Variation ,Virology ,3. Good health ,030104 developmental biology ,Influenza in Birds ,North America ,biology.protein ,Chickens - Abstract
Subtype H7 avian–origin influenza A viruses (AIVs) have caused at least 500 confirmed human infections since 2003 and culling of >75 million birds in recent years. Here we antigenically and genetically characterized 93 AIV isolates from North America (85 from migratory waterfowl [1976–2010], 7 from domestic poultry [1971–2012], and 1 from a seal [1980]). The hemagglutinin gene of these H7 viruses are separated from those from Eurasia. Gradual accumulation of nucleotide and amino acid substitutions was observed in the hemagglutinin of H7 AIVs from waterfowl and domestic poultry. Genotype characterization suggested that H7 AIVs in wild birds form diverse and transient internal gene constellations. Serologic analyses showed that the 93 isolates cross-reacted with each other to different extents. Antigenic cartography showed that the average antigenic distance among them was 1.14 units (standard deviation [SD], 0.57 unit) and that antigenic diversity among the H7 isolates we tested was limited. Our results suggest that the continuous genetic evolution has not led to significant antigenic diversity for H7 AIVs from North America. These findings add to our understanding of the natural history of IAVs and will inform public health decision-making regarding the threat these viruses pose to humans and poultry.
- Published
- 2016
11. Predicting Influenza Vaccine Effectiveness With Hemagglutinin Sequences Is Not Enough
- Author
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Jianqiang Ye and Yifei Xu
- Subjects
0301 basic medicine ,Microbiology (medical) ,biology ,Influenza vaccine ,business.industry ,030106 microbiology ,Hemagglutinin (influenza) ,medicine.disease_cause ,Virology ,Epitope ,03 medical and health sciences ,0302 clinical medicine ,Infectious Diseases ,biology.protein ,Influenza A virus ,medicine ,030212 general & internal medicine ,Medical science ,business - Published
- 2018
12. H3N2 Mismatch of 2014–15 Northern Hemisphere Influenza Vaccines and Head-to-head Comparison between Human and Ferret Antisera derived Antigenic Maps
- Author
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Meng-Jung Chiang, Yangqing Zhao, Anding Zhang, Ewan P. Plant, Toshiaki Kawano, Xianghong Jing, Yanhong Zhu, Courtney Finch, Hang Xie, Xiu-Feng Wan, Nan Zhao, Xing Li, Zhengshi Lin, Olga Zoueva, Yifei Xu, and Zhiping Ye
- Subjects
Adult ,Models, Molecular ,Influenza vaccine ,Biology ,Cross Reactions ,medicine.disease_cause ,Virus ,Article ,Serology ,03 medical and health sciences ,0302 clinical medicine ,Antigen ,Lectins ,Influenza, Human ,Influenza A virus ,medicine ,Animals ,Humans ,030212 general & internal medicine ,Child ,Antigens, Viral ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,Hemagglutination assay ,Immune Sera ,Influenza A Virus, H3N2 Subtype ,Vaccination ,Ferrets ,Hemagglutination Inhibition Tests ,Virology ,3. Good health ,Protein Structure, Tertiary ,Titer ,Influenza Vaccines - Abstract
The poor performance of 2014–15 Northern Hemisphere (NH) influenza vaccines was attributed to mismatched H3N2 component with circulating epidemic strains. Using human serum samples collected from 2009–10, 2010–11 and 2014–15 NH influenza vaccine trials, we assessed their cross-reactive hemagglutination inhibition (HAI) antibody responses against recent H3 epidemic isolates. All three populations (children, adults and older adults) vaccinated with the 2014–15 NH egg- or cell-based vaccine, showed >50% reduction in HAI post-vaccination geometric mean titers against epidemic H3 isolates from those against egg-grown H3 vaccine strain A/Texas/50/2012 (TX/12e). The 2014–15 NH vaccines, regardless of production type, failed to further extend HAI cross-reactivity against H3 epidemic strains from previous seasonal vaccines. Head-to-head comparison between ferret and human antisera derived antigenic maps revealed different antigenic patterns among representative egg- and cell-grown H3 viruses characterized. Molecular modeling indicated that the mutations of epidemic H3 strains were mainly located in antibody-binding sites A and B as compared with TX/12e. To improve vaccine strain selection, human serologic testing on vaccination-induced cross-reactivity need be emphasized along with virus antigenic characterization by ferret model.
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- 2015
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13. Potency, efficacy, and antigenic mapping of H7 avian influenza virus vaccines against the 2012 H7N3 highly pathogenic avian influenza virus from Mexico
- Author
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Darrell R. Kapczynski, Xiu-Feng Wan, David L. Suarez, Mary J. Pantin-Jackwood, Yifei Xu, Erica Spackman, and David E. Swayne
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Hemagglutinin Glycoproteins, Influenza Virus ,Biology ,medicine.disease_cause ,Antibodies, Viral ,Microbiology ,Influenza A Virus, H7N3 Subtype ,Food Animals ,Influenza A virus ,medicine ,Potency ,Animals ,Mexico ,Poultry Diseases ,Hemagglutination assay ,General Immunology and Microbiology ,Vaccination ,Outbreak ,Hemagglutination Inhibition Tests ,Vaccine efficacy ,Virology ,Influenza A virus subtype H5N1 ,Vaccine Potency ,Influenza Vaccines ,Influenza in Birds ,Animal Science and Zoology ,Chickens ,Epitope Mapping - Abstract
In the spring of 2012 an outbreak of H7N3 highly pathogenic (HP) avian influenza virus (AIV) occurred in poultry in Mexico. Vaccination was implemented as a control measure, along with increased biosecurity and surveillance. At that time there was no commercially available H7 AIV vaccine in North America; therefore, a recent H7N3 wild bird isolate of low pathogenicity from Mexico (A/cinnamon teal/Mexico/2817/2006 H7N3) was selected and utilized as the vaccine seed strain. In these studies, the potency and efficacy of this vaccine strain was evaluated in chickens against challenge with the 2012 Jalisco H7N3 HPAIV. Although vaccine doses of 256 and 102 hemagglutinating units (HAU) per bird decreased morbidity and mortality significantly compared to sham vaccinates, a dose of 512 HAU per bird was required to prevent mortality and morbidity completely. Additionally, the efficacy of 11 other H7 AIV vaccines and an antigenic map of hemagglutination inhibition assay data with all the vaccines and challenge viruses were evaluated, both to identify other potential vaccine strains and to characterize the relationship between genetic and antigenic distance with protection against this HPAIV. Several other isolates provided adequate protection against the 2012 Jalisco H7N3 lineage, but antigenic and genetic differences were not clear indicators of protection because the immunogenicity of the vaccine seed strain was also a critical factor.
- Published
- 2014
14. Error-prone pcr-based mutagenesis strategy for rapidly generating high-yield influenza vaccine candidates
- Author
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Jialiang Yang, G. Todd Pharr, Jianqiang Ye, Feng Wen, Xiu-Feng Wan, Richard J. Webby, Hailiang Sun, Nan Zhao, Li-Ping Long, Jim Cooley, and Yifei Xu
- Subjects
Influenza vaccine ,Mutagenesis (molecular biology technique) ,High-yield strain ,Biology ,medicine.disease_cause ,Polymerase Chain Reaction ,Virus ,Article ,Influenza A Virus, H1N1 Subtype ,Orthomyxoviridae Infections ,Virology ,Influenza A virus ,medicine ,Animals ,Technology, Pharmaceutical ,Mice, Inbred BALB C ,Error-prone PCR ,Strain (biology) ,Vaccine production ,Outbreak ,Survival Analysis ,Reverse genetics ,Reverse Genetics ,3. Good health ,Vaccination ,Disease Models, Animal ,Influenza Vaccines ,Mutagenesis ,Female ,Vaccine - Abstract
Vaccination is the primary strategy for the prevention and control of influenza outbreaks. However, the manufacture of influenza vaccine requires a high-yield seed strain, and the conventional methods for generating such strains are time consuming. In this study, we developed a novel method to rapidly generate high-yield candidate vaccine strains by integrating error-prone PCR, site-directed mutagenesis strategies, and reverse genetics. We used this method to generate seed strains for the influenza A(H1N1)pdm09 virus and produced six high-yield candidate strains. We used a mouse model to assess the efficacy of two of the six candidate strains as a vaccine seed virus: both strains provided complete protection in mice against lethal challenge, thus validating our method. Results confirmed that the efficacy of these candidate vaccine seed strains was not affected by the yield-optimization procedure.
- Published
- 2014
15. Detection of Avian H7N9 Influenza A Viruses in the Yangtze Delta Region of China During Early H7N9 Outbreaks
- Author
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Li Yin, Yao-Xing Liu, Xiao-Yan Liu, Richard J. Webby, Li-Ping Long, Chang-Hai Chen, Kong-Wang He, Xiu-Feng Wan, Dong-Min Zhao, Feng Fan, Kai-Kai Han, Jing Yang, Yuzhuo Liu, Xin-Mei Huang, Yifei Xu, Xingxing Xie, and You-Fa Zhang
- Subjects
China ,Veterinary medicine ,viruses ,Biosecurity ,Biology ,Influenza A Virus, H7N9 Subtype ,medicine.disease_cause ,Article ,Virus ,Disease Outbreaks ,Food Animals ,Pandemic ,Influenza A Virus, H9N2 Subtype ,Influenza A virus ,medicine ,Animals ,Phylogeny ,Poultry Diseases ,Epizootic ,General Immunology and Microbiology ,business.industry ,Outbreak ,Poultry farming ,medicine.disease ,Virology ,Influenza A virus subtype H5N1 ,Ducks ,Influenza in Birds ,Animal Science and Zoology ,business ,Chickens - Abstract
Since the first H7N9 human case in Shanghai, February 19, 2013, the emerging avian-origin H7N9 influenza A virus has become an epizootic virus in China, posing a potential pandemic threat to public health. From April 2 to April 28, 2013, some 422 oral-pharyngeal and cloacal swabs were collected from birds and environmental surfaces at five live poultry markets (LPMs) and 13 backyard poultry farms (BPFs) across three cities, Wuxi, Suzhou, and Nanjing, in the Yangtze Delta region. In total 22 isolates were recovered, and six were subtyped as H7N9, nine as H9N2, four as H7N9/H9N2, and three unsubtyped influenza A viruses. Genomic sequences showed that the HA and NA genes of the H7N9 viruses were similar to those of the H7N9 human isolates, as well as other avian-origin H7N9 isolates in the region, but the PB1, PA, NP, and MP genes of the sequenced viruses were more diverse. Among the four H7N9/H9N2 mixed infections, three were from LPM, whereas the other one was from the ducks at one BPF, which were H7N9 negative in serologic analyses. A survey of the bird trading records of the LPMs and BPFs indicates that trading was a likely route for virus transmission across these regions. Our results suggested that better biosecurity and more effective vaccination should be implemented in backyard farms, in addition to biosecurity management in LPMs.
- Published
- 2015
16. Zoonotic Risk, Pathogenesis, and Transmission of Avian-Origin H3N2 Canine Influenza Virus.
- Author
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Hailiang Sun, Blackmon, Sherry, Guohua Yang, Waters, Kaitlyn, Tao Li, Tangwangvivat, Ratanaporn, Yifei Xu, Daniel Shyu, Feng Wen, Jim Cooley, Senter, Lucy, Xiaoxu Lin, Jarman, Richard, Hanson, Larry, Webby, Richard, and Xiu-Feng Wan
- Subjects
- *
ZOONOSES , *INFLUENZA transmission , *PHENOTYPES , *NUCLEOPROTEINS , *HEMAGGLUTININ genetics , *INFLUENZA A virus, H1N1 subtype , *DISEASE risk factors - Abstract
Two subtypes of influenza A virus (IAV), avian-origin canine influenza virus (CIV) H3N2 (CIV-H3N2) and equine-origin CIV H3N8 (CIV-H3N8), are enzootic in the canine population. Dogs have been demonstrated to seroconvert in response to diverse IAVs, and naturally occurring reassortants of CIV-H3N2 and the 2009 H1N1 pandemic virus (pdmH1N1) have been isolated. We conducted a thorough phenotypic evaluation of CIV-H3N2 in order to assess its threat to human health. Using ferret-generated antiserum, we determined that CIV-H3N2 is antigenically distinct from contemporary human H3N2 IAVs, suggesting that there may be minimal herd immunity in humans. We assessed the public health risk of CIV-H3N2 × pandemic H1N1 (pdmH1N1) reassortants by characterizing their in vitro genetic compatibility and in vivo pathogenicity and transmissibility. Using a luciferase minigenome assay, we quantified the polymerase activity of all possible 16 ribonucleoprotein (RNP) complexes (PB2, PB1, PA, NP) between CIV-H3N2 and pdmH1N1, identifying some combinations that were more active than either parental virus complex. Using reverse genetics and fixing the CIV-H3N2 hemagglutinin (HA), we found that 51 of the 127 possible reassortant viruses were viable and able to be rescued. Nineteen of these reassortant viruses had high-growth phenotypes in vitro, and 13 of these replicated in mouse lungs. A single reassortant with the NP and HA gene segments from CIV-H3N2 was selected for characterization in ferrets. The reassortant was efficiently transmitted by contact but not by the airborne route and was pathogenic in ferrets. Our results suggest that CIV-H3N2 reassortants may pose a moderate risk to public health and that the canine host should be monitored for emerging IAVs. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
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