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Abstract
In 1918, a strain of influenza A virus caused a human pandemic resulting in the deaths of 50 million people. A century later, with the advent of sequencing technology and corresponding phylogenetic methods, we know much more about the origins, evolution and epidemiology of influenza epidemics. Here we review the history of avian influenza viruses through the lens of their genetic makeup: from their relationship to human pandemic viruses, starting with the 1918 H1N1 strain, through to the highly pathogenic epidemics in birds and zoonoses up to 2018. We describe the genesis of novel influenza A virus strains by reassortment and evolution in wild and domestic bird populations, as well as the role of wild bird migration in their long-range spread. The emergence of highly pathogenic avian influenza viruses, and the zoonotic incursions of avian H5 and H7 viruses into humans over the last couple of decades are also described. The threat of a new avian influenza virus causing a human pandemic is still present today, although control in domestic avian populations can minimize the risk to human health. This article is part of the theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes’. This issue is linked with the subsequent theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control’.
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Affiliation(s)
| | | | - Paul Digard
- The Roslin Institute, University of Edinburgh , Edinburgh , UK
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2
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Ancient pathogen genomics: insights into timing and adaptation. J Hum Evol 2014; 79:137-49. [PMID: 25532802 DOI: 10.1016/j.jhevol.2014.11.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 09/08/2014] [Accepted: 11/05/2014] [Indexed: 12/15/2022]
Abstract
Disease is a major cause of natural selection affecting human evolution, whether through a sudden pandemic or persistent morbidity and mortality. Recent contributions in the field of ancient pathogen genomics have advanced our understanding of the antiquity and nature of human-pathogen interactions through time. Technical advancements have facilitated the recovery, enrichment, and high-throughput sequencing of pathogen and parasite DNA from archived and archaeological remains. These time-stamped genomes are crucial for calibrating molecular clocks to infer the timing of evolutionary events, while providing finer-grain resolution to phylogenetic reconstructions and complex biogeographical patterns. Additionally, genome scale data allow better identification of substitutions linked to adaptations of the pathogen to their human hosts. As methodology continues to improve, ancient genomes of humans and their diverse microbiomes from a range of eras and archaeological contexts will enable population-level ancient analyses in the near future and a better understanding of their co-evolutionary history.
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Zhang N, Zheng BJ, Lu L, Zhou Y, Jiang S, Du L. Advancements in the development of subunit influenza vaccines. Microbes Infect 2014; 17:123-34. [PMID: 25529753 DOI: 10.1016/j.micinf.2014.12.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/07/2014] [Accepted: 12/08/2014] [Indexed: 12/19/2022]
Abstract
The ongoing threat of influenza epidemics and pandemics has emphasized the importance of developing safe and effective vaccines against infections from divergent influenza viruses. In this review, we first introduce the structure and life cycle of influenza A viruses, describing major influenza A virus-caused pandemics. We then compare different types of influenza vaccines and discuss current advancements in the development of subunit influenza vaccines, particularly those based on nucleoprotein (NP), extracellular domain of matrix protein 2 (M2e) and hemagglutinin (HA) proteins. We also illustrate potential strategies for improving the efficacy of subunit influenza vaccines.
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Affiliation(s)
- Naru Zhang
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, USA
| | - Bo-Jian Zheng
- Department of Microbiology, University of Hong Kong, Pokfulam, Hong Kong
| | - Lu Lu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College and Institute of Medical Microbiology, Fudan University, Shanghai, China
| | - Yusen Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Shibo Jiang
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, USA; Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Shanghai Medical College and Institute of Medical Microbiology, Fudan University, Shanghai, China.
| | - Lanying Du
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, USA.
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Genetic diversity of early (1998) and recent (2010) avian influenza H9N2 virus strains isolated from poultry in Iran. Arch Virol 2013; 158:2089-100. [DOI: 10.1007/s00705-013-1699-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 03/11/2013] [Indexed: 10/26/2022]
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Wang Z, Gao J, Yu Q, Yang Q. Oral immunization with recombinant Lactococcus lactis expressing the hemagglutinin of the avian influenza virus induces mucosal and systemic immune responses. Future Microbiol 2013; 7:1003-10. [PMID: 22913358 DOI: 10.2217/fmb.12.69] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
AIMS The aim of the study in this article is to explore a safe, convenient and effective oral mucosal vaccine candidate against highly pathogenic avian influenza. MATERIALS & METHODS We have constructed an oral mucosal vaccine, LL36EH, by use of the genetically stable θ-replicating vector pMG36E, which expressed the fusion protein hemagglutinin 1 (HA(1)) in a live carrier, Lactococcus lactis MG1363. LL36EH was administered orally to mice three times at 2-week intervals. The specific serum IgG and mucosal IgA antibodies were detected and evaluated at different time points after immunization. RESULTS The results showed that LL36EH could significantly induce specific anti-HA(1) IgA antibody in the intestine and specific anti-HA(1) IgG antibody in the serum (p < 0.05). Additionally, when the splenic lymphocytes isolated from immunized mice were stimulated by HA(1) antigen in vitro, splenic lymphocyte proliferative reaction and secretions of the cytokines IFN-γ and IL-4 were also significantly increased. Most importantly, the mice that were immunized with LL36EH were protected to some extent against lethal challenge of the H5N1 virus. CONCLUSION LL36EH triggered the anti-HA(1)-specific humoral and cellular immune responses and protective immunity. Therefore, oral immunization with LL36EH could be a valuable strategy against highly pathogenic avian influenza for humans and animals.
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Affiliation(s)
- Zhisheng Wang
- Key Lab of Animal Physiology & Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Weigang 1, Nanjing, Jiangsu 210095, China
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Mucosal and systemic immune responses induced by recombinant Lactobacillus spp. expressing the hemagglutinin of the avian influenza virus H5N1. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 19:174-9. [PMID: 22131355 DOI: 10.1128/cvi.05618-11] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To develop a safe, effective, and convenient vaccine for the prevention of highly pathogenic avian influenza (HPAI), we have successfully constructed two recombinant lactobacillus strains (LA4356-pH and DLD17-pH) that express the foreign HPAI virus protein hemagglutinin 1 (HA(1)). The mucosal and systemic immune responses triggered by these two recombinant lactobacilli following oral administration to BALB/c mice were evaluated. The results showed that both LA4356-pH and DLD17-pH could significantly increase the specific anti-HA(1) IgA antibody level in the mucosa and the anti-HA(1) IgG level in serum, as well as stimulating the splenic lymphocyte proliferative reaction through increased expression of interleukin-4 (IL-4). Compared with LA4356-pH, DLD17-pH was more effective at inducing systemic and mucosal immune responses, with higher anti-HA(1)-specific IgA and IgG levels. Therefore, DLD17-pH could be a promising oral vaccine candidate against HPAI.
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Ping J, Keleta L, Forbes NE, Dankar S, Stecho W, Tyler S, Zhou Y, Babiuk L, Weingartl H, Halpin RA, Boyne A, Bera J, Hostetler J, Fedorova NB, Proudfoot K, Katzel DA, Stockwell TB, Ghedin E, Spiro DJ, Brown EG. Genomic and protein structural maps of adaptive evolution of human influenza A virus to increased virulence in the mouse. PLoS One 2011; 6:e21740. [PMID: 21738783 PMCID: PMC3128085 DOI: 10.1371/journal.pone.0021740] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Accepted: 06/10/2011] [Indexed: 12/11/2022] Open
Abstract
Adaptive evolution is characterized by positive and parallel, or repeated selection of mutations. Mouse adaptation of influenza A virus (IAV) produces virulent mutants that demonstrate positive and parallel evolution of mutations in the hemagglutinin (HA) receptor and non-structural protein 1 (NS1) interferon antagonist genes. We now present a genomic analysis of all 11 genes of 39 mouse adapted IAV variants from 10 replicate adaptation experiments. Mutations were mapped on the primary and structural maps of each protein and specific mutations were validated with respect to virulence, replication, and RNA polymerase activity. Mouse adapted (MA) variants obtained after 12 or 20–21 serial infections acquired on average 5.8 and 7.9 nonsynonymous mutations per genome of 11 genes, respectively. Among a total of 115 nonsynonymous mutations, 51 demonstrated properties of natural selection including 27 parallel mutations. The greatest degree of parallel evolution occurred in the HA receptor and ribonucleocapsid components, polymerase subunits (PB1, PB2, PA) and NP. Mutations occurred in host nuclear trafficking factor binding sites as well as sites of virus-virus protein subunit interaction for NP, NS1, HA and NA proteins. Adaptive regions included cap binding and endonuclease domains in the PB2 and PA polymerase subunits. Four mutations in NS1 resulted in loss of binding to the host cleavage and polyadenylation specificity factor (CPSF30) suggesting that a reduction in inhibition of host gene expression was being selected. The most prevalent mutations in PB2 and NP were shown to increase virulence but differed in their ability to enhance replication and demonstrated epistatic effects. Several positively selected RNA polymerase mutations demonstrated increased virulence associated with >300% enhanced polymerase activity. Adaptive mutations that control host range and virulence were identified by their repeated selection to comprise a defined model for studying IAV evolution to increased virulence in the mouse.
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Affiliation(s)
- Jihui Ping
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Emerging Pathogens Research Centre, University of Ottawa, Ottawa, Ontario, Canada
- Canadian Institutes of Health Research (CIHR) Canadian Influenza Pathogenesis Team, University of Ottawa, Ottawa, Ontario, Canada
| | - Liya Keleta
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Emerging Pathogens Research Centre, University of Ottawa, Ottawa, Ontario, Canada
- Canadian Institutes of Health Research (CIHR) Canadian Influenza Pathogenesis Team, University of Ottawa, Ottawa, Ontario, Canada
| | - Nicole E. Forbes
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Emerging Pathogens Research Centre, University of Ottawa, Ottawa, Ontario, Canada
- Canadian Institutes of Health Research (CIHR) Canadian Influenza Pathogenesis Team, University of Ottawa, Ottawa, Ontario, Canada
| | - Samar Dankar
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Emerging Pathogens Research Centre, University of Ottawa, Ottawa, Ontario, Canada
- Canadian Institutes of Health Research (CIHR) Canadian Influenza Pathogenesis Team, University of Ottawa, Ottawa, Ontario, Canada
| | - William Stecho
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Emerging Pathogens Research Centre, University of Ottawa, Ottawa, Ontario, Canada
| | - Shaun Tyler
- National Microbiology Laboratory, Canadian Science Centre for Human and Animal Health, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Yan Zhou
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Canadian Institutes of Health Research (CIHR) Canadian Influenza Pathogenesis Team, University of Ottawa, Ottawa, Ontario, Canada
| | - Lorne Babiuk
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Canadian Institutes of Health Research (CIHR) Canadian Influenza Pathogenesis Team, University of Ottawa, Ottawa, Ontario, Canada
| | - Hana Weingartl
- National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, Manitoba, Canada
- Canadian Institutes of Health Research (CIHR) Canadian Influenza Pathogenesis Team, University of Ottawa, Ottawa, Ontario, Canada
| | - Rebecca A. Halpin
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Alex Boyne
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Jayati Bera
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Jessicah Hostetler
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Nadia B. Fedorova
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Katie Proudfoot
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Dan A. Katzel
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Tim B. Stockwell
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Elodie Ghedin
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
- Center for Vaccine Research, Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - David J. Spiro
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
- Viral Genomics Group, J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Earl G. Brown
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Emerging Pathogens Research Centre, University of Ottawa, Ottawa, Ontario, Canada
- Canadian Institutes of Health Research (CIHR) Canadian Influenza Pathogenesis Team, University of Ottawa, Ottawa, Ontario, Canada
- Canadian Institutes of Health Research (CIHR) Canadian Influenza Pathogenesis Team, University of Ottawa, Ottawa, Ontario, Canada
- * E-mail:
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8
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Wahlgren J. Influenza A viruses: an ecology review. Infect Ecol Epidemiol 2011; 1:IEE-1-6004. [PMID: 22957113 PMCID: PMC3426330 DOI: 10.3402/iee.v1i0.6004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 01/18/2011] [Accepted: 01/18/2011] [Indexed: 01/08/2023] Open
Abstract
In humans, influenza A viruses cause yearly outbreaks with high morbidity and excess fatality rates as a direct effect. Placed in its ecological niche, however - in dabbling ducks - avian influenza virus (AIV) induces quite a mild disease. It is when the virus crosses the species barrier that pathogenic traits are attributed to infection. When infecting phylogenetically more distant species (i.e. chicken and turkeys), the AIV can cause high morbidity and may in some cases change the virus into a highly pathogenic variant with nearly 100% fatality rate. Being a very adaptable virus, these spill-over events are frequent and numerous species are susceptible to influenza virus. When a subtype of AIV that has not previously infected humans crosses the species barrier, adapts to humans, and spreads easily, a pandemic event is imminent. There is no cure for influenza infection and vaccination is a cumbersome endeavor so, currently, the strategy when a pandemic strikes is damage control. The interest in AIV ecology has increased dramatically since the beginning of the millennium as a key factor for preventive work for future pandemics. This review gives a broad overview of influenza A virus ecology: in the natural host, accidental hosts, new endemic hosts, and humans.
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Affiliation(s)
- John Wahlgren
- Department for Preparedness, Swedish Institute for Infectious Disease Control, Solna, Sweden
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9
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Lin T, Wang G, Li A, Zhang Q, Wu C, Zhang R, Cai Q, Song W, Yuen KY. The hemagglutinin structure of an avian H1N1 influenza A virus. Virology 2009; 392:73-81. [PMID: 19628241 DOI: 10.1016/j.virol.2009.06.028] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 05/22/2009] [Accepted: 06/17/2009] [Indexed: 12/09/2022]
Abstract
The interaction between hemagglutinin (HA) and receptors is a kernel in the study of evolution and host adaptation of H1N1 influenza A viruses. The notion that the avian HA is associated with preferential specificity for receptors with Siaalpha2,3Gal glycosidic linkage over those with Siaalpha2,6Gal linkage is not all consistent with the available data on H1N1 viruses. By x-ray crystallography, the HA structure of an avian H1N1 influenza A virus, as well as its complexes with the receptor analogs, was determined. The structures revealed no preferential binding of avian receptor analogs over that of the human analog, suggesting that the HA/receptor binding might not be as stringent as is commonly believed in determining the host receptor preference for some subtypes of influenza viruses, such as the H1N1 viruses. The structure also showed difference in glycosylation despite the preservation of related sequences, which may partly contribute to the difference between structures of human and avian origin.
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Affiliation(s)
- Tianwei Lin
- School of Life Sciences, Xiamen University, Xiamen, PR China.
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10
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Wallensten A. Influenza virus in wild birds and mammals other than man. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2009. [DOI: 10.1080/08910600701406786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Anders Wallensten
- Smedby Health Center, Kalmar County Council, Kalmar, Sweden
- Division of Molecular Virology, Department of Molecular and Clinical Medicine (IMK), Faculty of Health Sciences, Linköping University, Linköping, Sweden
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11
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McCall S, Vilensky JA, Gilman S, Taubenberger JK. The relationship between encephalitis lethargica and influenza: a critical analysis. J Neurovirol 2008; 14:177-85. [PMID: 18569452 PMCID: PMC2778472 DOI: 10.1080/13550280801995445] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Since encephalitis lethargica's (EL) prevalence in the 1920s, epidemiologic and clinical debate has persisted over whether EL was caused by, potentiated by, or merely coincident with the Spanish influenza pandemic. Epidemiologic analyses generally suggest that the disorders were coincidental. Beginning in the 1970s, modern experiments on archival brain samples mainly failed to confirm a direct relationship between influenza and EL. These experimental studies have technical limitations, e.g., the appropriateness of antibodies, polymerase chain reaction (PCR) primers and controls, and the extreme paucity and age of available material. These factors render the case against influenza less decisive than currently perceived. Nevertheless, there is little direct evidence supporting influenza in the etiology of EL. Almost 100 years after the EL epidemic, its etiology remains enigmatic, raising the possibility of a recurrence of EL in a future influenza pandemic.
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Affiliation(s)
- Sherman McCall
- Department of Clinical Pathology, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, USA
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12
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Taubenberger JK, Hultin JV, Morens DM. Discovery and Characterization of the 1918 Pandemic Influenza Virus in Historical Context. Antivir Ther 2007. [DOI: 10.1177/135965350701200s02.1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The 2005 completion of the entire genome sequence of the 1918 H1N1 pandemic influenza virus represents both a beginning and an end. Investigators have already begun to study the virus in vitro and in vivo to better understand its properties, pathogenicity, transmissibility and elicitation of host responses. Although this is an exciting new beginning, characterization of the 1918 virus also represents the culmination of over a century of scientific research aiming to understand the causes of pandemic influenza. In this brief review we attempt to place in historical context the identification and sequencing of the 1918 virus, including the alleged discovery of a bacterial cause of influenza during the 1889–1893 pandemic, the controversial detection of ‘filter-passing agents’ during the 1918–1919 pandemic, and subsequent breakthroughs in the 1930s that led to isolation of human and swine influenza viruses, greatly influencing the development of modern virology.
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Affiliation(s)
- Jeffery K Taubenberger
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Johan V Hultin
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - David M Morens
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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13
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Abstract
Influenza A viral infection causes substantial annual morbidity and mortality worldwide, particularly for infants, the elderly, and the immunocompromised. The virus mainly replicates in the respiratory tract and is spread by respiratory secretions. A growing concern is the recent identification of H5N1 strains of avian influenza A in Asia that were previously thought to infect only wild birds and poultry, but have now infected humans, cats, pigs, and other mammals, often with fatal results, in an ongoing outbreak. A human pandemic with H5N1 virus could potentially be catastrophic because most human populations have negligible antibody-mediated immunity to the H5 surface protein and this viral subtype is highly virulent. Whether an H5N1 influenza pandemic will occur is likely to hinge on whether the viral strains involved in the current outbreak acquire additional mutations that facilitate efficient human-to-human transfer of infection. Although there is no historical precedent for an H5N1 avian strain causing widespread human-to-human transmission, some type of influenza A pandemic is very likely in the near future. The possibility of an H5N1 influenza pandemic has highlighted the many current limitations of treatment with antiviral agents and of vaccine production and immunogenicity. Future vaccine strategies that may include more robust induction of T-cell responses, such as cytotoxic T lymphocytes, may provide better protection than is offered by current vaccines, which rely solely or mainly on antibody neutralization of infection.
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Affiliation(s)
- David B Lewis
- Department of Pediatrics and Program in Immunology, Stanford University School of Medicine, Stanford, California 94305, USA.
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Parrish CR, Kawaoka Y. The origins of new pandemic viruses: the acquisition of new host ranges by canine parvovirus and influenza A viruses. Annu Rev Microbiol 2006; 59:553-86. [PMID: 16153179 DOI: 10.1146/annurev.micro.59.030804.121059] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transfer of viruses between hosts to create a new self-sustaining epidemic is rare; however, those new viruses can cause severe outbreaks. Examples of such viruses include three pandemic human influenza A viruses and canine parvovirus in dogs. In each case one virus made the original transfer and spread worldwide, and then further adaptation resulted in the emergence of variants worldwide. For the influenza viruses several changes were required for growth and spread between humans, and the emergence of human H2N2 and H3N2 strains in 1957 and 1968 involved the acquisition of three or two new genomic segments, respectively. Adaptation to humans involved several viral genes including the hemagglutinin, the neuraminidase, and the replication proteins. The canine adaptation of the parvoviruses involved capsid protein changes altering the recognition of the host transferrin receptors, allowing canine transferrin receptor binding and its use as a receptor for cell infection.
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Affiliation(s)
- Colin R Parrish
- J. A. Baker Institute, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
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16
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Abstract
The "Spanish" influenza pandemic of 1918-1919, which caused approximately 50 million deaths worldwide, remains an ominous warning to public health. Many questions about its origins, its unusual epidemiologic features, and the basis of its pathogenicity remain unanswered. The public health implications of the pandemic therefore remain in doubt even as we now grapple with the feared emergence of a pandemic caused by H5N1 or other virus. However, new information about the 1918 virus is emerging, for example, sequencing of the entire genome from archival autopsy tissues. But, the viral genome alone is unlikely to provide answers to some critical questions. Understanding the 1918 pandemic and its implications for future pandemics requires careful experimentation and in-depth historical analysis.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Aging
- Animals
- Child
- Child, Preschool
- Disease Outbreaks/history
- Disease Outbreaks/statistics & numerical data
- Evolution, Molecular
- History, 20th Century
- Humans
- Infant
- Infant, Newborn
- Influenza A Virus, H1N1 Subtype/genetics
- Influenza A Virus, H1N1 Subtype/pathogenicity
- Influenza, Human/epidemiology
- Influenza, Human/history
- Influenza, Human/virology
- Middle Aged
- Virulence
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Abstract
The "Spanish" influenza pandemic of 1918-1919, which caused approximately 50 million deaths worldwide, remains an ominous warning to public health. Many questions about its origins, its unusual epidemiologic features, and the basis of its pathogenicity remain unanswered. The public health implications of the pandemic therefore remain in doubt even as we now grapple with the feared emergence of a pandemic caused by H5N1 or other virus. However, new information about the 1918 virus is emerging, for example, sequencing of the entire genome from archival autopsy tissues. But, the viral genome alone is unlikely to provide answers to some critical questions. Understanding the 1918 pandemic and its implications for future pandemics requires careful experimentation and in-depth historical analysis.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Aging
- Animals
- Child
- Child, Preschool
- Disease Outbreaks/history
- Disease Outbreaks/statistics & numerical data
- Evolution, Molecular
- History, 20th Century
- Humans
- Infant
- Infant, Newborn
- Influenza A Virus, H1N1 Subtype/genetics
- Influenza A Virus, H1N1 Subtype/pathogenicity
- Influenza, Human/epidemiology
- Influenza, Human/history
- Influenza, Human/virology
- Middle Aged
- Virulence
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Reid AH, Fanning TG, Janczewski TA, Lourens RM, Taubenberger JK. Novel origin of the 1918 pandemic influenza virus nucleoprotein gene. J Virol 2004; 78:12462-70. [PMID: 15507633 PMCID: PMC525067 DOI: 10.1128/jvi.78.22.12462-12470.2004] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The nucleoprotein (NP) gene of the 1918 pandemic influenza A virus has been amplified and sequenced from archival material. The NP gene is known to be involved in many aspects of viral function and to interact with host proteins, thereby playing a role in host specificity. The 1918 NP amino acid sequence differs at only six amino acids from avian consensus sequences, consistent with reassortment from an avian source shortly before 1918. However, the nucleotide sequence of the 1918 NP gene has more than 170 differences from avian strain consensus sequences, suggesting substantial evolutionary distance from known avian strain sequences. Both the gene and protein sequences of the 1918 NP fall within the mammalian clade upon phylogenetic analysis. The evolutionary distance of the 1918 NP sequences from avian and mammalian strain sequences is examined, using several different parameters. The results suggest that the 1918 strain did not retain the previously circulating human NP. Nor is it likely to have obtained its NP by reassortment with an avian strain similar to those now characterized. The results are consistent with the existence of a currently unknown host for influenza, with an NP similar to current avian strain NPs at the amino acid level but with many synonymous nucleotide differences, suggesting evolutionary isolation from the currently characterized avian influenza virus gene pool.
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Affiliation(s)
- Ann H Reid
- Armed Forces Institute of Pathology, Department of Molecular Pathology, 1413 Research Blvd., Building 101, Rockville, MD 20850-3125, USA
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Bush RM. Influenza as a model system for studying the cross-species transfer and evolution of the SARS coronavirus. Philos Trans R Soc Lond B Biol Sci 2004; 359:1067-73. [PMID: 15306391 PMCID: PMC1693400 DOI: 10.1098/rstb.2004.1481] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus (SARS-CoV) moved into humans from a reservoir species and subsequently caused an epidemic in its new host. We know little about the processes that allowed the cross-species transfer of this previously unknown virus. I discuss what we have learned about the movement of viruses into humans from studies of influenza A, both how it crossed from birds to humans and how it subsequently evolved within the human population. Starting with a brief review of severe acute respiratory syndrome to highlight the kinds of problems we face in learning about this viral disease, I then turn to influenza A, focusing on three topics. First, I present a reanalysis of data used to test the hypothesis that swine served as a "mixing vessel" or intermediate host in the transmission of avian influenza to humans during the 1918 "Spanish flu" pandemic. Second, I review studies of archived viruses from the three recent influenza pandemics. Third, I discuss current limitations in using molecular data to study the evolution of infectious disease. Although influenza A and SARS-CoV differ in many ways, our knowledge of influenza A may provide important clues about what limits or favours cross-species transfers and subsequent epidemics of newly emerging pathogens.
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Affiliation(s)
- Robin M Bush
- Department of Ecology and Evolutionary Biology, 321 Steinhaus, University of California, Irvine, CA 92697, USA.
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Reid AH, Taubenberger JK, Fanning TG. Evidence of an absence: the genetic origins of the 1918 pandemic influenza virus. Nat Rev Microbiol 2004; 2:909-14. [PMID: 15494747 PMCID: PMC7097663 DOI: 10.1038/nrmicro1027] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Annual outbreaks of influenza A infection are an ongoing public health threat and novel influenza strains can periodically emerge to which humans have little immunity, resulting in devastating pandemics. The 1918 pandemic killed at least 40 million people worldwide and pandemics in 1957 and 1968 caused hundreds of thousands of deaths. The influenza A virus is capable of enormous genetic variation, both by continuous, gradual mutation and by reassortment of genome segments between viruses. Both the 1957 and 1968 pandemic strains are thought to have originated as reassortants in which one or both human-adapted viral surface proteins were replaced by proteins from avian influenza strains. Analyses of the genes of the 1918 pandemic virus, however, indicate that this strain might have had a different origin. The haemagglutinin and nucleoprotein genome segments in particular are unlikely to have come directly from an avian source that is similar to those that are currently being sequenced. Determining whether a pandemic influenza virus can emerge by different mechanisms will affect the scope and focus of surveillance and prevention efforts.
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Affiliation(s)
- Ann H. Reid
- Department of Molecular Pathology, Armed Forces Institute of Pathology, 1413 Research Boulevard., Building 101, Rockville, 20850 Maryland USA
| | - Jeffery K. Taubenberger
- Department of Molecular Pathology, Armed Forces Institute of Pathology, 1413 Research Boulevard., Building 101, Rockville, 20850 Maryland USA
| | - Thomas G. Fanning
- Department of Molecular Pathology, Armed Forces Institute of Pathology, 1413 Research Boulevard., Building 101, Rockville, 20850 Maryland USA
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