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Petro-Turnquist E, Madapong A, Steffen D, Weaver EA. Immunogenicity and Protective Efficacy of Dose-Sparing Epigraph Vaccine against H3 Swine Influenza A Virus. Vaccines (Basel) 2024; 12:943. [PMID: 39204066 PMCID: PMC11359338 DOI: 10.3390/vaccines12080943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2024] [Revised: 08/16/2024] [Accepted: 08/19/2024] [Indexed: 09/03/2024] Open
Abstract
Swine influenza A virus (IAV-S) is a highly prevalent and transmissible pathogen infecting worldwide swine populations. Our previous work has shown that the computationally derived vaccine platform, Epigraph, can induce broadly cross-reactive and durable immunity against H3 IAV-S in mice and swine. Therefore, in this study, we assess the immunogenicity and protective efficacy of the Epigraph vaccine at increasingly lower doses to determine the minimum dose required to maintain protective immunity against three genetically divergent H3 IAV-S. We assessed both antibody and T cell responses and then challenged with three H3N2 IAV-S derived from either Cluster IV(A), Cluster I, or the 2010.1 "human-like" cluster and assessed protection through reduced pathology, reduced viral load in the lungs, and reduced viral shedding from nasal swabs. Overall, we observed a dose-dependent effect where the highest dose of Epigraph protected against all three challenges, the middle dose of Epigraph protected against more genetically similar IAV-S, and the lowest dose of Epigraph only protected against genetically similar IAV-S. The results of these studies can be used to continue developing a broadly protective and low-dose vaccine against H3 IAV-S.
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Affiliation(s)
- Erika Petro-Turnquist
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; (E.P.-T.); (A.M.)
| | - Adthakorn Madapong
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; (E.P.-T.); (A.M.)
| | - David Steffen
- Nebraska Veterinary Diagnostics Center, Lincoln, NE 68583, USA;
| | - Eric A. Weaver
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; (E.P.-T.); (A.M.)
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Petro-Turnquist E, Pekarek MJ, Weaver EA. Swine influenza A virus: challenges and novel vaccine strategies. Front Cell Infect Microbiol 2024; 14:1336013. [PMID: 38633745 PMCID: PMC11021629 DOI: 10.3389/fcimb.2024.1336013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 03/21/2024] [Indexed: 04/19/2024] Open
Abstract
Swine Influenza A Virus (IAV-S) imposes a significant impact on the pork industry and has been deemed a significant threat to global public health due to its zoonotic potential. The most effective method of preventing IAV-S is vaccination. While there are tremendous efforts to control and prevent IAV-S in vulnerable swine populations, there are considerable challenges in developing a broadly protective vaccine against IAV-S. These challenges include the consistent diversification of IAV-S, increasing the strength and breadth of adaptive immune responses elicited by vaccination, interfering maternal antibody responses, and the induction of vaccine-associated enhanced respiratory disease after vaccination. Current vaccination strategies are often not updated frequently enough to address the continuously evolving nature of IAV-S, fail to induce broadly cross-reactive responses, are susceptible to interference, may enhance respiratory disease, and can be expensive to produce. Here, we review the challenges and current status of universal IAV-S vaccine research. We also detail the current standard of licensed vaccines and their limitations in the field. Finally, we review recently described novel vaccines and vaccine platforms that may improve upon current methods of IAV-S control.
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Affiliation(s)
- Erika Petro-Turnquist
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, United States
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Matthew J. Pekarek
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, United States
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Eric A. Weaver
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE, United States
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
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3
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Zeller MA, Ma J, Wong FY, Tum S, Hidano A, Holt H, Chhay T, Sorn S, Koeut D, Seng B, Chao S, Ng GGK, Yan Z, Chou M, Rudge JW, Smith GJD, Su YCF. The genomic landscape of swine influenza A viruses in Southeast Asia. Proc Natl Acad Sci U S A 2023; 120:e2301926120. [PMID: 37552753 PMCID: PMC10438389 DOI: 10.1073/pnas.2301926120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 06/07/2023] [Indexed: 08/10/2023] Open
Abstract
Swine are a primary source for the emergence of pandemic influenza A viruses. The intensification of swine production, along with global trade, has amplified the transmission and zoonotic risk of swine influenza A virus (swIAV). Effective surveillance is essential to uncover emerging virus strains; however gaps remain in our understanding of the swIAV genomic landscape in Southeast Asia. More than 4,000 nasal swabs were collected from pigs in Cambodia, yielding 72 IAV-positive samples by RT-qPCR and 45 genomic sequences. We unmasked the cocirculation of multiple lineages of genetically diverse swIAV of pandemic concern. Genomic analyses revealed a novel European avian-like H1N2 swIAV reassortant variant with North American triple reassortant internal genes, that emerged approximately seven years before its first detection in pigs in 2021. Using phylogeographic reconstruction, we identified south central China as the dominant source of swine viruses disseminated to other regions in China and Southeast Asia. We also identified nine distinct swIAV lineages in Cambodia, which diverged from their closest ancestors between two and 15 B.P., indicating significant undetected diversity in the region, including reverse zoonoses of human H1N1/2009 pandemic and H3N2 viruses. A similar period of cryptic circulation of swIAVs occurred in the decades before the H1N1/2009 pandemic. The hidden diversity of swIAV observed here further emphasizes the complex underlying evolutionary processes present in this region, reinforcing the importance of genomic surveillance at the human-swine interface for early warning of disease emergence to avoid future pandemics.
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Affiliation(s)
- Michael A. Zeller
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore169857, Singapore
| | - Jordan Ma
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore169857, Singapore
| | - Foong Ying Wong
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore169857, Singapore
| | - Sothyra Tum
- National Animal Health and Production Research Institute, General Directorate of Animal Health and Production, Phnom Penh120608, Cambodia
| | - Arata Hidano
- Department of Global Health and Development, London School of Hygiene & Tropical Medicine, LondonWC1E 7HT, United Kingdom
| | - Hannah Holt
- Department of Global Health and Development, London School of Hygiene & Tropical Medicine, LondonWC1E 7HT, United Kingdom
| | - Ty Chhay
- Livestock Development for Community Livelihood, Phnom Penh120108, Cambodia
| | - San Sorn
- National Animal Health and Production Research Institute, General Directorate of Animal Health and Production, Phnom Penh120608, Cambodia
| | - Dina Koeut
- National Animal Health and Production Research Institute, General Directorate of Animal Health and Production, Phnom Penh120608, Cambodia
| | - Bunnary Seng
- National Animal Health and Production Research Institute, General Directorate of Animal Health and Production, Phnom Penh120608, Cambodia
| | - Sovanncheypo Chao
- National Animal Health and Production Research Institute, General Directorate of Animal Health and Production, Phnom Penh120608, Cambodia
| | - Giselle G. K. Ng
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore169857, Singapore
| | - Zhuang Yan
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore169857, Singapore
| | - Monidarin Chou
- University of Health Sciences, Phnom Penh120210, Cambodia
| | - James W. Rudge
- Department of Global Health and Development, London School of Hygiene & Tropical Medicine, LondonWC1E 7HT, United Kingdom
| | - Gavin J. D. Smith
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore169857, Singapore
- Centre for Outbreak Preparedness, Duke-NUS Medical School, Singapore169857, Singapore
- SingHealth Duke-NUS Global Health Institute,SingHealth Duke-NUS Academic Medical Centre, Singapore169857, Singapore
- Duke Global Health Institute, Duke University, Durham, NC27708
| | - Yvonne C. F. Su
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore169857, Singapore
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Kumari S, Chaudhari J, Huang Q, Gauger P, De Almeida MN, Liang Y, Ly H, Vu HLX. Immunogenicity and Protective Efficacy of a Recombinant Pichinde Viral-Vectored Vaccine Expressing Influenza Virus Hemagglutinin Antigen in Pigs. Vaccines (Basel) 2022; 10:vaccines10091400. [PMID: 36146478 PMCID: PMC9505097 DOI: 10.3390/vaccines10091400] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 11/26/2022] Open
Abstract
Influenza A virus of swine (IAV-S) is an economically important swine pathogen. The IAV-S hemagglutinin (HA) surface protein is the main target for vaccine development. In this study, we evaluated the feasibility of using the recombinant tri-segmented Pichinde virus (rPICV) as a viral vector to deliver HA antigen to protect pigs against IAV-S challenge. Four groups of weaned pigs (T01–T04) were included in the study. T01 was injected with PBS to serve as a non-vaccinated control. T02 was inoculated with rPICV expressing green fluorescence protein (rPICV-GFP). T03 was vaccinated with rPICV expressing the HA antigen of the IAV-S H3N2 strain (rPICV-H3). T04 was vaccinated with the recombinant HA protein antigen of the same H3N2 strain. Pigs were vaccinated twice at day 0 and day 21 and challenged at day 43 by intra-tracheal inoculation with the homologous H3N2 IAV-S strain. After vaccination, all pigs in T03 and T04 groups were seroconverted and exhibited high titers of plasma neutralizing antibodies. After challenge, high levels of IAV-S RNA were detected in the nasal swabs and bronchioalveolar lavage fluid of pigs in T01 and T02 but not in the T03 and T04 groups. Similarly, lung lesions were observed in T01 and T02, but not in the T03 and T04 groups. No significant difference in terms of protection was observed between the T03 and T04 group. Collectively, our results demonstrate that the rPICV-H3 vectored vaccine elicited protective immunity against IAV-S challenge. This study shows that rPICV is a promising viral vector for the development of vaccines against IAV-S.
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Affiliation(s)
- Sushmita Kumari
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Jayeshbhai Chaudhari
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Qinfeng Huang
- Veterinary & Biomedical Sciences Department, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN 55108, USA
| | - Phillip Gauger
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Marcelo Nunes De Almeida
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Yuying Liang
- Veterinary & Biomedical Sciences Department, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN 55108, USA
| | - Hinh Ly
- Veterinary & Biomedical Sciences Department, College of Veterinary Medicine, University of Minnesota, Twin Cities, MN 55108, USA
- Correspondence: (H.L.); (H.L.X.V.); Tel.: +1-612-625-3358 (H.L.); +1-402-472-4528 (H.L.X.V.)
| | - Hiep L. X. Vu
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
- Department of Animals Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
- Correspondence: (H.L.); (H.L.X.V.); Tel.: +1-612-625-3358 (H.L.); +1-402-472-4528 (H.L.X.V.)
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Zeller MA, Saxena A, Anderson TK, Vincent AL, Gauger PC. Use of the ISU FLUture multisequence identity tool for rapid interpretation of swine influenza A virus sequences in the United States. J Vet Diagn Invest 2022; 34:874-878. [PMID: 35879873 PMCID: PMC9446310 DOI: 10.1177/10406387221111128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Rapid and reliable identification of the hemagglutinin (HA) and neuraminidase (NA) genetic clades of an influenza A virus (IAV) sequence from swine can inform control measures and multivalent vaccine composition. Current approaches to genetically characterize HA or NA sequences are based on nucleotide similarity or phylogenetic analyses. Public databases exist to acquire IAV genetic sequences for comparison, but personnel at the diagnostic or production level have difficulty in adequately updating and maintaining relevant sequence datasets for IAV in swine. Further, phylogenetic analyses are time intensive, and inference drawn from these methods is impacted by input sequence data and associated metadata. We describe here the use of the IAV multisequence identity tool as an integrated public webpage located on the Iowa State University Veterinary Diagnostic Laboratory (ISU-VDL) FLUture website: https://influenza.cvm.iastate.edu/. The multisequence identity tool uses sequence data derived from IAV-positive cases sequenced at the ISU-VDL, employs a BLAST algorithm that identifies sequences that are genetically similar to submitted query sequences, and presents a tabulation and visualization of the most genetically similar IAV sequence and associated metadata from the FLUture database. Our tool removes bioinformatic barriers and allows clients, veterinarians, and researchers to rapidly classify and identify IAV sequences similar to their own sequences to augment interpretation of results.
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Affiliation(s)
- Michael A Zeller
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.,Current address: Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Anugrah Saxena
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Tavis K Anderson
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
| | - Amy L Vincent
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
| | - Phillip C Gauger
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
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6
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Wang Y, Tang CY, Wan XF. Antigenic characterization of influenza and SARS-CoV-2 viruses. Anal Bioanal Chem 2022; 414:2841-2881. [PMID: 34905077 PMCID: PMC8669429 DOI: 10.1007/s00216-021-03806-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/21/2021] [Accepted: 11/24/2021] [Indexed: 12/24/2022]
Abstract
Antigenic characterization of emerging and re-emerging viruses is necessary for the prevention of and response to outbreaks, evaluation of infection mechanisms, understanding of virus evolution, and selection of strains for vaccine development. Primary analytic methods, including enzyme-linked immunosorbent/lectin assays, hemagglutination inhibition, neuraminidase inhibition, micro-neutralization assays, and antigenic cartography, have been widely used in the field of influenza research. These techniques have been improved upon over time for increased analytical capacity, and some have been mobilized for the rapid characterization of the SARS-CoV-2 virus as well as its variants, facilitating the development of highly effective vaccines within 1 year of the initially reported outbreak. While great strides have been made for evaluating the antigenic properties of these viruses, multiple challenges prevent efficient vaccine strain selection and accurate assessment. For influenza, these barriers include the requirement for a large virus quantity to perform the assays, more than what can typically be provided by the clinical samples alone, cell- or egg-adapted mutations that can cause antigenic mismatch between the vaccine strain and circulating viruses, and up to a 6-month duration of vaccine development after vaccine strain selection, which allows viruses to continue evolving with potential for antigenic drift and, thus, antigenic mismatch between the vaccine strain and the emerging epidemic strain. SARS-CoV-2 characterization has faced similar challenges with the additional barrier of the need for facilities with high biosafety levels due to its infectious nature. In this study, we review the primary analytic methods used for antigenic characterization of influenza and SARS-CoV-2 and discuss the barriers of these methods and current developments for addressing these challenges.
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Affiliation(s)
- Yang Wang
- MU Center for Influenza and Emerging Infectious Diseases (CIEID), University of Missouri, Columbia, MO, USA
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Cynthia Y Tang
- MU Center for Influenza and Emerging Infectious Diseases (CIEID), University of Missouri, Columbia, MO, USA
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Institute for Data Science and Informatics, University of Missouri, Columbia, MO, USA
| | - Xiu-Feng Wan
- MU Center for Influenza and Emerging Infectious Diseases (CIEID), University of Missouri, Columbia, MO, USA.
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, USA.
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA.
- Institute for Data Science and Informatics, University of Missouri, Columbia, MO, USA.
- Department of Electrical Engineering & Computer Science, College of Engineering, University of Missouri, Columbia, MO, USA.
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Abstract
In 2017, the Iowa State University Veterinary Diagnostic Laboratory detected a reverse-zoonotic transmission of a human seasonal H3 influenza A virus into swine (IAV-S) in Oklahoma. Pairwise comparison between the recently characterized human seasonal H3 IAV-S (H3.2010.2) hemagglutinin (HA) sequences detected in swine and the most similar 2016-2017 human seasonal H3 revealed 99.9% nucleotide identity. To elucidate the origin of H3.2010.2 IAV-S, 45 HA and 27 neuraminidase (NA) sequences from 2017 to 2020 as well as 11 whole-genome sequences (WGS) were genetically characterized. Time to most recent common human ancestor was estimated between August and September 2016. The N2 NA was of human origin in all but one strain from diagnostic submissions with NA sequences, and the internal gene segments from WGS consisted of matrix genes originating from the 2009 pandemic H1N1 and another 5 internal genes of triple reassortant swine origin (TTTTPT). Pigs experimentally infected with H3.2010.2 demonstrated efficient nasal shedding and replication in the lungs, mild pneumonia, and minimal microscopic lung lesions and transmitted the virus to indirect contact swine. Antigenically, H3.2010.2 viruses were closer to a human seasonal vaccine strain, A/Hong Kong/4801/2014, than to the H3.2010.1 human seasonal H3 viruses detected in swine in 2012. This was the second sustained transmission of a human seasonal IAV into swine from the 2010 decade after H3.2010.1. Monitoring the spillover and detection of novel IAV from humans to swine may help vaccine antigen selection and could impact pandemic preparedness. IMPORTANCE H3.2010.2 is a new phylogenetic clade of H3N2 circulating in swine that became established after the spillover of a human seasonal H3N2 from the 2016-2017 influenza season. The novel H3.2010.2 transmitted and adapted to the swine host and demonstrated reassortment with internal genes from strains endemic to pigs, but it maintained human-like HA and NA. It is genetically and antigenically distinct from the H3.2010.1 H3N2 introduced earlier in the 2010 decade. Human seasonal IAV spillovers into swine become established in the population through adaptation and sustained transmission and contribute to the genetic and antigenic diversity of IAV circulating in swine. Continued IAV surveillance is necessary to detect emergence of novel strains in swine and assist with vaccine antigen selection to improve the ability to prevent respiratory disease in swine as well as the risk of zoonotic transmission.
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Antigenic distance between North American swine and human seasonal H3N2 influenza A viruses as an indication of zoonotic risk to humans. J Virol 2021; 96:e0137421. [PMID: 34757846 DOI: 10.1128/jvi.01374-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Human-to-swine transmission of influenza A virus (IAV) repeatedly occurs, leading to sustained transmission and increased diversity in swine; human seasonal H3N2 introductions occurred in the 1990s and 2010s and were maintained in North American swine. Swine H3N2 were subsequently associated with zoonotic infections, highlighting the need to understand the risk of endemic swine IAV to humans. We quantified antigenic distances between swine H3N2 and human seasonal vaccine strains from 1973 to 2014 using a panel of monovalent antisera raised in pigs in hemagglutination inhibition (HI) assays. Swine H3N2 lineages retained closest antigenic similarity to human vaccine strains from the decade of incursion. Swine lineages from the 1990s were antigenically more similar to human vaccine strains of the mid-1990s but had substantial distance from recent human vaccine strains. In contrast, lineages from the 2010s were closer to human vaccine strains from 2011 and 2014 and most antigenically distant from human vaccine strains prior to 2007. HI assays using ferret antisera demonstrated that swine lineages from the 1990s and 2010s had significant fold-reduction compared with the homologous HI titer of the nearest pandemic preparedness candidate vaccine virus (CVV) or seasonal vaccine strain. The assessment of post-infection and post-vaccination human sera cohorts demonstrated limited cross-reactivity to swine H3N2 from the 1990s, especially in older adults born before 1970s. We identified swine strains to which humans are likely to lack population immunity or are not protected against by a current human seasonal vaccine or CVV to use in prioritizing future human CVV strain selection. IMPORTANCE Human H3N2 influenza A viruses spread to pigs in North America in the 1990s and more recently in the 2010s. These cross-species events led to sustained circulation and increased H3N2 diversity in pig populations. Evolution of H3N2 in swine led to a reduced similarity with human seasonal H3N2 and the vaccine strains used to protect human populations. We quantified the antigenic phenotypes and found that North American swine H3N2 lineages retained more antigenic similarity to historical human vaccine strains from the decade of incursion but had substantial difference compared with recent human vaccine strains. Additionally, pandemic preparedness vaccine strains demonstrated a loss in similarity with contemporary swine strains. Lastly, human sera revealed that although these adults had antibodies against human H3N2 strains, many had limited immunity to swine H3N2, especially older adults born before 1970. Antigenic assessment of swine H3N2 provides critical information for pandemic preparedness and candidate vaccine development.
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9
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Zeller MA, Chang J, Vincent AL, Gauger PC, Anderson TK. Spatial and Temporal Coevolution of N2 Neuraminidase and H1 and H3 Hemagglutinin Genes of Influenza A Virus in United States Swine. Virus Evol 2021; 7:veab090. [PMID: 35223081 PMCID: PMC8864744 DOI: 10.1093/ve/veab090] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 09/14/2021] [Accepted: 10/07/2021] [Indexed: 11/12/2022] Open
Abstract
Abstract
The neuraminidase (NA) and hemagglutinin (HA) are essential surface glycoproteins of influenza A virus (IAV). In this study, the evolution of subtype N2 NA paired with H1 and H3 subtype HA in swine was evaluated to understand if genetic diversity of HA and NA were linked. Using time-scaled Bayesian phylodynamic analyses, the relationships of paired swine N2 with H1 or H3 from 2009 to 2018 were evaluated. These data demonstrated increased relative genetic diversity within the major N2 clades circulating in swine in the United States (N2.1998 between 2014-2017 and N2.2002 between 2010-2016). Preferential pairing was observed among specific NA and HA genetic clades. Gene reassortment between cocirculating influenza A strains resulted in novel pairings that persisted. The changes of genetic diversity in the NA gene were quantified using Bayesian phylodynamic analyses and increases in diversity were observed subsequent to novel NA-HA reassortment events. The rate of evolution among NA-N2 clades and HA-H1 and HA-H3 clades were similar. Bayesian phylodynamic analyses demonstrated strong spatial patterns in N2 genetic diversity, but frequent interstate movement of rare N2 clades provided opportunity for reassortment and emergence of new N2-HA pairings. The frequent regional movement of pigs and their influenza viruses is an explanation for the documented patterns of reassortment and subsequent changes in gene diversity. The reassortment and evolution of NA and linked HA evolution may result in antigenic drift of both major surface glycoproteins, reducing vaccine efficacy, with subsequent impact on animal health.
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Affiliation(s)
- Michael A Zeller
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
- Bioinformatics and Computational Biology Program, Iowa State University, Ames, IA 50011, USA
| | - Jennifer Chang
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA 50010, USA
| | - Amy L Vincent
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA 50010, USA
| | - Phillip C Gauger
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Tavis K Anderson
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA 50010, USA
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Kaplan BS, Anderson TK, Chang J, Santos J, Perez D, Lewis N, Vincent AL. Evolution and Antigenic Advancement of N2 Neuraminidase of Swine Influenza A Viruses Circulating in the United States following Two Separate Introductions from Human Seasonal Viruses. J Virol 2021; 95:e0063221. [PMID: 34379513 PMCID: PMC8475526 DOI: 10.1128/jvi.00632-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/15/2021] [Indexed: 12/15/2022] Open
Abstract
Two separate introductions of human seasonal N2 neuraminidase genes were sustained in U.S. swine since 1998 (N2-98) and 2002 (N2-02). Herein, we characterized the antigenic evolution of the N2 of swine influenza A virus (IAV) across 2 decades following each introduction. The N2-98 and N2-02 expanded in genetic diversity, with two statistically supported monophyletic clades within each lineage. To assess antigenic drift in swine N2 following the human-to-swine spillover events, we generated a panel of swine N2 antisera against representative N2 and quantified the antigenic distance between wild-type viruses using enzyme-linked lectin assay and antigenic cartography. The antigenic distance between swine and human N2 was smallest between human N2 circulating at the time of each introduction and the archetypal swine N2. However, sustained circulation and evolution in swine of the two N2 lineages resulted in significant antigenic drift, and the N2-98 and N2-02 swine N2 lineages were antigenically distinct. Although intralineage antigenic diversity was observed, the magnitude of antigenic drift did not consistently correlate with the observed genetic differences. These data represent the first quantification of the antigenic diversity of neuraminidase of IAV in swine and demonstrated significant antigenic drift from contemporary human seasonal strains as well as antigenic variation among N2 detected in swine. These data suggest that antigenic mismatch may occur between circulating swine IAV and vaccine strains. Consequently, consideration of the diversity of N2 in swine IAV for vaccine selection may likely result in more effective control and aid public health initiatives for pandemic preparedness. IMPORTANCE Antibodies inhibiting the neuraminidase (NA) of IAV reduce clinical disease, virus shedding, and transmission, particularly in the absence of neutralizing immunity against hemagglutinin. To understand antibody recognition of the genetically diverse NA in U.S. swine IAV, we characterized the antigenic diversity of N2 from swine and humans. N2 detected in swine IAV were derived from two distinct human-to-swine spillovers that persisted, are antigenically distinct, and underwent antigenic drift. These findings highlight the need for continued surveillance and vaccine development in swine with increased focus on the NA. Additionally, human seasonal N2 isolated after 2005 were poorly inhibited by representative swine N2 antisera, suggesting a lack of cross-reactive NA antibody-mediated immunity between contemporary swine and human N2. Bidirectional transmission between humans and swine represents a One Health challenge, and determining the correlates of immunity to emerging IAV strains is critical to mitigating zoonotic and reverse-zoonotic transmission.
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Affiliation(s)
- Bryan S. Kaplan
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, USA
| | - Tavis K. Anderson
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, USA
| | - Jennifer Chang
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, USA
| | - Jefferson Santos
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Daniel Perez
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Nicola Lewis
- Department of Pathobiology and Population Sciences, The Royal Veterinary College, University of London, London, Hertfordshire, UK
| | - Amy L. Vincent
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, USA
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11
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Anderson TK, Chang J, Arendsee ZW, Venkatesh D, Souza CK, Kimble JB, Lewis NS, Davis CT, Vincent AL. Swine Influenza A Viruses and the Tangled Relationship with Humans. Cold Spring Harb Perspect Med 2021; 11:cshperspect.a038737. [PMID: 31988203 PMCID: PMC7919397 DOI: 10.1101/cshperspect.a038737] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Influenza A viruses (IAVs) are the causative agents of one of the most important viral respiratory diseases in pigs and humans. Human and swine IAV are prone to interspecies transmission, leading to regular incursions from human to pig and vice versa. This bidirectional transmission of IAV has heavily influenced the evolutionary history of IAV in both species. Transmission of distinct human seasonal lineages to pigs, followed by sustained within-host transmission and rapid adaptation and evolution, represent a considerable challenge for pig health and production. Consequently, although only subtypes of H1N1, H1N2, and H3N2 are endemic in swine around the world, extensive diversity can be found in the hemagglutinin (HA) and neuraminidase (NA) genes, as well as the remaining six genes. We review the complicated global epidemiology of IAV in swine and the inextricably entangled implications for public health and influenza pandemic planning.
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Affiliation(s)
- Tavis K. Anderson
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa 50010, USA
| | - Jennifer Chang
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa 50010, USA
| | - Zebulun W. Arendsee
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa 50010, USA
| | - Divya Venkatesh
- Department of Pathology and Population Sciences, Royal Veterinary College, University of London, Hertfordshire AL9 7TA, United Kingdom
| | - Carine K. Souza
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa 50010, USA
| | - J. Brian Kimble
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa 50010, USA
| | - Nicola S. Lewis
- Department of Pathology and Population Sciences, Royal Veterinary College, University of London, Hertfordshire AL9 7TA, United Kingdom
| | - C. Todd Davis
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
| | - Amy L. Vincent
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa 50010, USA
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12
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Tabaszewski P, Gorecki P, Markin A, Anderson T, Eulenstein O. Consensus of All Solutions for Intractable Phylogenetic Tree Inference. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2021; 18:149-161. [PMID: 31613775 DOI: 10.1109/tcbb.2019.2947051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Solving median tree problems is a classic approach for inferring species trees from a collection of discordant gene trees. Median tree problems are typically NP-hard and dealt with by local search heuristics. Unfortunately, such heuristics generally lack provable correctness and precision. Algorithmic advances addressing this uncertainty have led to exact dynamic programming formulations suitable to solve a well-studied group of median tree problems for smaller phylogenetic analyses. However, these formulations allow computing only very few optimal species trees out of possibly many such trees, and phylogenetic studies often require the analysis of all optimal solutions through their consensus tree. Here, we describe a significant algorithmic modification of the dynamic programming formulations that compute the cluster counts of all optimal species trees from which various types of consensus trees can be efficiently computed. Through experimental studies, we demonstrate that our parallel implementation of the modified dynamic programming formulation is more efficient than a previous implementation of the original formulation. Finally, we show that the parallel implementation can rapidly identify novel reassorted influenza A viruses potentially facilitating pandemic preparedness efforts.
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13
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Chauhan RP, Gordon ML. A Systematic Review Analyzing the Prevalence and Circulation of Influenza Viruses in Swine Population Worldwide. Pathogens 2020; 9:pathogens9050355. [PMID: 32397138 PMCID: PMC7281378 DOI: 10.3390/pathogens9050355] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/02/2020] [Accepted: 04/09/2020] [Indexed: 01/04/2023] Open
Abstract
The global anxiety and a significant threat to public health due to the current COVID-19 pandemic reiterate the need for active surveillance for the zoonotic virus diseases of pandemic potential. Influenza virus due to its wide host range and zoonotic potential poses such a significant threat to public health. Swine serve as a “mixing vessel” for influenza virus reassortment and evolution which as a result may facilitate the emergence of new strains or subtypes of zoonotic potential. In this context, the currently available scientific data hold a high significance to unravel influenza virus epidemiology and evolution. With this objective, the current systematic review summarizes the original research articles and case reports of all the four types of influenza viruses reported in swine populations worldwide. A total of 281 articles were found eligible through screening of PubMed and Google Scholar databases and hence were included in this systematic review. The highest number of research articles (n = 107) were reported from Asia, followed by Americas (n = 97), Europe (n = 55), Africa (n = 18), and Australia (n = 4). The H1N1, H1N2, H3N2, and A(H1N1)pdm09 viruses were the most common influenza A virus subtypes reported in swine in most countries across the globe, however, few strains of influenza B, C, and D viruses were also reported in certain countries. Multiple reports of the avian influenza virus strains documented in the last two decades in swine in China, the United States, Canada, South Korea, Nigeria, and Egypt provided the evidence of interspecies transmission of influenza viruses from birds to swine. Inter-species transmission of equine influenza virus H3N8 from horse to swine in China expanded the genetic diversity of swine influenza viruses. Additionally, numerous reports of the double and triple-reassortant strains which emerged due to reassortments among avian, human, and swine strains within swine further increased the genetic diversity of swine influenza viruses. These findings are alarming hence active surveillance should be in place to prevent future influenza pandemics.
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14
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Sharma A, Zeller MA, Li G, Harmon KM, Zhang J, Hoang H, Anderson TK, Vincent AL, Gauger PC. Detection of live attenuated influenza vaccine virus and evidence of reassortment in the U.S. swine population. J Vet Diagn Invest 2020; 32:301-311. [PMID: 32100644 DOI: 10.1177/1040638720907918] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Influenza vaccines historically have been multivalent, whole virus inactivated products. The first bivalent, intranasal, live attenuated influenza vaccine (LAIV; Ingelvac Provenza), with H1N1 and H3N2 subtypes, has been approved for use in swine. We investigated the LAIV hemagglutinin (HA) sequences in diagnostic cases submitted to the Iowa State University Veterinary Diagnostic Laboratory and potential vaccine virus reassortment with endemic influenza A virus (IAV) in swine. From January 3 to October 11, 2018, IAV HA sequences demonstrating 99.5-99.9% nucleotide homology to the H1 HA or 99.4-100% nucleotide homology to the H3 HA parental strains in the LAIV were detected in 58 of 1,116 (5.2%) porcine respiratory cases (H1 HA A/swine/Minnesota/37866/1999[H1N1; MN99]; H3 HA A/swine/Texas/4199-2/1998[H3N2; TX98]). Nine cases had co-detection of HA genes from LAIV and wild-type IAV in the same specimen. Thirty-five cases had associated epidemiologic information that indicated they were submitted from 11 states representing 31 individual sites and 17 production systems in the United States. Whole genome sequences from 11 cases and another subset of 2 plaque-purified IAV were included in our study. Ten whole genome sequences, including 1 plaque-purified IAV, contained at least one internal gene from endemic IAV detected within the past 3 y. Phylogenetic analysis of whole genome sequences indicated that reassortment occurred between vaccine virus and endemic field strains circulating in U.S. swine. Our data highlight the need and importance of continued IAV surveillance to detect emerging IAV with LAIV genes in the swine population.
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Affiliation(s)
- Aditi Sharma
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA (Sharma, Zeller, Li, Harmon, Zhang, Gauger).,Bioinformatics and Computational Biology Graduate Program (Zeller), Iowa State University, Ames, IA.,Animal Husbandry and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam (Hoang).,Virus and Prion Research Unit, National Animal Disease Center, USDA-Agricultural Research Service, Ames, IA (Anderson, Vincent)
| | - Michael A Zeller
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA (Sharma, Zeller, Li, Harmon, Zhang, Gauger).,Bioinformatics and Computational Biology Graduate Program (Zeller), Iowa State University, Ames, IA.,Animal Husbandry and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam (Hoang).,Virus and Prion Research Unit, National Animal Disease Center, USDA-Agricultural Research Service, Ames, IA (Anderson, Vincent)
| | - Ganwu Li
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA (Sharma, Zeller, Li, Harmon, Zhang, Gauger).,Bioinformatics and Computational Biology Graduate Program (Zeller), Iowa State University, Ames, IA.,Animal Husbandry and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam (Hoang).,Virus and Prion Research Unit, National Animal Disease Center, USDA-Agricultural Research Service, Ames, IA (Anderson, Vincent)
| | - Karen M Harmon
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA (Sharma, Zeller, Li, Harmon, Zhang, Gauger).,Bioinformatics and Computational Biology Graduate Program (Zeller), Iowa State University, Ames, IA.,Animal Husbandry and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam (Hoang).,Virus and Prion Research Unit, National Animal Disease Center, USDA-Agricultural Research Service, Ames, IA (Anderson, Vincent)
| | - Jianqiang Zhang
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA (Sharma, Zeller, Li, Harmon, Zhang, Gauger).,Bioinformatics and Computational Biology Graduate Program (Zeller), Iowa State University, Ames, IA.,Animal Husbandry and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam (Hoang).,Virus and Prion Research Unit, National Animal Disease Center, USDA-Agricultural Research Service, Ames, IA (Anderson, Vincent)
| | - Hai Hoang
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA (Sharma, Zeller, Li, Harmon, Zhang, Gauger).,Bioinformatics and Computational Biology Graduate Program (Zeller), Iowa State University, Ames, IA.,Animal Husbandry and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam (Hoang).,Virus and Prion Research Unit, National Animal Disease Center, USDA-Agricultural Research Service, Ames, IA (Anderson, Vincent)
| | - Tavis K Anderson
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA (Sharma, Zeller, Li, Harmon, Zhang, Gauger).,Bioinformatics and Computational Biology Graduate Program (Zeller), Iowa State University, Ames, IA.,Animal Husbandry and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam (Hoang).,Virus and Prion Research Unit, National Animal Disease Center, USDA-Agricultural Research Service, Ames, IA (Anderson, Vincent)
| | - Amy L Vincent
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA (Sharma, Zeller, Li, Harmon, Zhang, Gauger).,Bioinformatics and Computational Biology Graduate Program (Zeller), Iowa State University, Ames, IA.,Animal Husbandry and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam (Hoang).,Virus and Prion Research Unit, National Animal Disease Center, USDA-Agricultural Research Service, Ames, IA (Anderson, Vincent)
| | - Phillip C Gauger
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA (Sharma, Zeller, Li, Harmon, Zhang, Gauger).,Bioinformatics and Computational Biology Graduate Program (Zeller), Iowa State University, Ames, IA.,Animal Husbandry and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Vietnam (Hoang).,Virus and Prion Research Unit, National Animal Disease Center, USDA-Agricultural Research Service, Ames, IA (Anderson, Vincent)
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15
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Abstract
Influenza A viruses (IAVs) of the Orthomyxoviridae virus family cause one of the most important respiratory diseases in pigs and humans. Repeated outbreaks and rapid spread of genetically and antigenically distinct IAVs represent a considerable challenge for animal production and public health. Bidirection transmission of IAV between pigs and people has altered the evolutionary dynamics of IAV, and a "One Health" approach is required to ameliorate morbidity and mortality in both hosts and improve control strategies. Although only subtypes of H1N1, H1N2, and H3N2 are endemic in swine around the world, considerable diversity can be found not only in the hemagglutinin (HA) and neuraminidase (NA) genes but in the remaining six genes as well. Human and swine IAVs have demonstrated a particular propensity for interspecies transmission, leading to regular and sometimes sustained incursions from man to pig and vice versa. The diversity of IAVs in swine remains a critical challenge in the diagnosis and control of this important pathogen for swine health and in turn contributes to a significant public health risk.
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Affiliation(s)
- Amy L Vincent
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA.
| | - Tavis K Anderson
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
| | - Kelly M Lager
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
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16
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Sun H, Sur JH, Sillman S, Steffen D, Vu HLX. Design and characterization of a consensus hemagglutinin vaccine immunogen against H3 influenza A viruses of swine. Vet Microbiol 2019; 239:108451. [PMID: 31767095 DOI: 10.1016/j.vetmic.2019.108451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/02/2019] [Accepted: 10/06/2019] [Indexed: 11/25/2022]
Abstract
The substantial genetic diversity exhibited by influenza A viruses of swine (IAV-S) represents the main challenge for the development of a broadly protective vaccine against this important pathogen. The consensus vaccine immunogen has proven an effective vaccinology approach to overcome the extraordinary genetic diversity of RNA viruses. In this project, we sought to determine if a consensus IAV-S hemagglutinin (HA) immunogen would elicit broadly protective immunity in pigs. To address this question, a consensus HA gene (designated H3-CON.1) was generated from a set of 1,112 H3 sequences of IAV-S recorded in GenBank from 2011 to 2015. The consensus HA gene and a HA gene of a naturally occurring H3N2 IAV-S strain (designated H3-TX98) were expressed using the baculovirus expression system and emulsified in an oil-in-water adjuvant to be used for vaccination. Pigs vaccinated with H3-CON.1 immunogen elicited broader levels of cross-reactive neutralizing antibodies and interferon gamma secreting cells than those vaccinated with H3-TX98 immunogen. After challenge infection with a fully infectious H3N2 IAV-S isolate, the H3-CON.1-vaccinated pigs shed significantly lower levels of virus in their nasal secretions than the H3-TX98-vaccinated pigs. Collectively, our data provide a proof-of-evidence that the consensus immunogen approach may be effectively employed to develop a broadly protective vaccine against IAV-S.
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Affiliation(s)
- Haiyan Sun
- Nebraska Center for Virology and Department of Animal Science, University of Nebraska, Lincoln, Nebraska, USA
| | - Jung-Hyang Sur
- Department of Veterinary Pathology, College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea
| | - Sarah Sillman
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - David Steffen
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Hiep L X Vu
- Nebraska Center for Virology and Department of Animal Science, University of Nebraska, Lincoln, Nebraska, USA.
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17
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octoFLU: Automated Classification for the Evolutionary Origin of Influenza A Virus Gene Sequences Detected in U.S. Swine. Microbiol Resour Announc 2019; 8:8/32/e00673-19. [PMID: 31395641 PMCID: PMC6687928 DOI: 10.1128/mra.00673-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The diversity of the 8 genes of influenza A viruses (IAV) in swine reflects introductions from nonswine hosts and subsequent antigenic drift and shift. Here, we curated a data set and present a pipeline that assigns evolutionary lineage and genetic clade to query gene segments.
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