Emerging Role of Mucosal Vaccine in Preventing Infection with Avian Influenza A Viruses

Avian influenza A viruses (AIVs), as a zoonotic agent, dramatically impacts public health and the poultry industry. Although low pathogenic avian influenza virus (LPAIV) incidence and mortality are relatively low, the infected hosts can act as a virus carrier and provide a resource pool for reassortant influenza viruses. At present, vaccination is the most effective way to eradicate AIVs from commercial poultry. The inactivated vaccines can only stimulate humoral immunity, rather than cellular and mucosal immune responses, while failing to effectively inhibit the replication and spread of AIVs in the flock. In recent years, significant progresses have been made in the understanding of the mechanisms underlying the vaccine antigen activities at the mucosal surfaces and the development of safe and efficacious mucosal vaccines that mimic the natural infection route and cut off the AIVs infection route. Here, we discussed the current status and advancement on mucosal immunity, the means of establishing mucosal immunity, and finally a perspective for design of AIVs mucosal vaccines. Hopefully, this review will help to not only understand and predict AIVs infection characteristics in birds but also extrapolate them for distinction or applicability in mammals, including humans.

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Swine influenza vaccines: current status and future perspectives

Animal Health Research Reviews ◽

10.1017/s146625231000006x ◽

2010 ◽

Vol 11 (1) ◽

pp. 81-96 ◽

Cited By ~ 41

Author(s):

Wenjun Ma ◽

Jürgen A. Richt

Keyword(s):

Influenza A ◽

Swine Influenza ◽

Influenza Viruses ◽

Current Status ◽

Economic Losses ◽

Influenza A Viruses ◽

Swine Industry ◽

Effective Strategies ◽

Swine Disease ◽

And Control

AbstractSwine influenza is an important contagious disease in pigs caused by influenza A viruses. Although only three subtypes of influenza A viruses, H1N1, H1N2 and H3N2, predominantly infect pigs worldwide, it is still a big challenge for vaccine manufacturers to produce efficacious vaccines for the prevention and control of swine influenza. Swine influenza viruses not only cause significant economic losses for the swine industry, but are also important zoonotic pathogens. Vaccination is still one of the most important and effective strategies to prevent and control influenza for both the animal and human population. In this review, we will discuss the current status of swine influenza worldwide as well as current and future options to control this economically important swine disease.

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Reassortment and persistence of influenza A viruses from diverse geographic origins within Australian wild birds: evidence from a small, isolated population of Ruddy turnstones

Journal of Virology ◽

10.1128/jvi.02193-20 ◽

2021 ◽

Author(s):

Bethany J. Hoye ◽

Celeste M. Donato ◽

Simeon Lisovski ◽

Yi-Mo Deng ◽

Simone Warner ◽

...

Keyword(s):

Avian Influenza ◽

Influenza A ◽

Wild Birds ◽

Influenza Viruses ◽

Low Density ◽

Isolated Population ◽

Influenza A Viruses ◽

Geographic Origins ◽

Eastern Australia

Australian lineages of avian influenza A viruses (AIVs) are thought to be phylogenetically distinct from those circulating in Eurasia and the Americas, suggesting the circulation of endemic viruses seeded by occasional introductions from other regions. However, processes underlying the introduction, evolution and maintenance of AIVs in Australia remain poorly understood. Waders (Order Charadriiformes, Family Scolopacidae) may play a unique role in the ecology and evolution of AIVs, particularly in Australia, where ducks, geese and swans (Order Anseriformes, Family Anatidae) rarely undertake intercontinental migrations. Across a five-year surveillance period (2011–2015), Ruddy turnstones (Arenaria interpres) that ‘overwinter’ during the Austral summer in south eastern Australia showed generally low levels of AIV prevalence (0–2%). However, in March 2014 we detected AIVs in 32% (95% CI; 25–39%) of individuals in a small, low-density, island population 90km from the Australian mainland. This epizootic comprised three distinct AIV genotypes, each of which represent a unique reassortment of Australian, recently introduced Eurasian, and recently introduced American-lineage gene segments. Strikingly, the Australian-lineage gene segments showed high similarity to H10N7 viruses isolated in 2010 and 2012 from poultry outbreaks 900–1500km to the north. Together with the diverse geographic origins of the American and Eurasian gene segments, these findings suggest extensive circulation and reassortment of AIVs within Australian wild birds over vast geographic distances. Our findings indicate that long-term surveillance in waders may yield unique insights into AIV gene flow, especially in geographic regions like Oceania where Anatidae do not display regular inter- or intracontinental migration. IMPORTANCE High prevalence of avian influenza viruses (AIVs) was detected in a small, low-density, isolated population of Ruddy turnstones in Australia. Analysis of these viruses revealed relatively recent introductions of viral gene segments from both Eurasia and North America, as well as long-term persistence of introduced gene segments in Australian wild birds. These data demonstrate that the flow of viruses into Australia may be more common than initially thought and that, once introduced, these AIVs have the potential to be maintained within the continent. These findings add to a growing body of evidence suggesting Australian wild birds are unlikely to be ecologically-isolated from the highly pathogenic H5Nx viruses circulating among wild birds throughout the northern hemisphere.

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Molecular Basis for the Generation in Pigs of Influenza A Viruses with Pandemic Potential

Journal of Virology ◽

10.1128/jvi.72.9.7367-7373.1998 ◽

1998 ◽

Vol 72 (9) ◽

pp. 7367-7373 ◽

Cited By ~ 626

Author(s):

Toshihiro Ito ◽

J. Nelson S. S. Couceiro ◽

Sørge Kelm ◽

Linda G. Baum ◽

Scott Krauss ◽

...

Keyword(s):

Avian Influenza ◽

Influenza A ◽

Influenza Viruses ◽

Structural Basis ◽

Human Populations ◽

Influenza A Viruses ◽

Human Virus ◽

Surface Receptors ◽

Virus Receptors ◽

Avian Influenza A Virus

ABSTRACT Genetic and biologic observations suggest that pigs may serve as “mixing vessels” for the generation of human-avian influenza A virus reassortants, similar to those responsible for the 1957 and 1968 pandemics. Here we demonstrate a structural basis for this hypothesis. Cell surface receptors for both human and avian influenza viruses were identified in the pig trachea, providing a milieu conducive to viral replication and genetic reassortment. Surprisingly, with continued replication, some avian-like swine viruses acquired the ability to recognize human virus receptors, raising the possibility of their direct transmission to human populations. These findings help to explain the emergence of pandemic influenza viruses and support the need for continued surveillance of swine for viruses carrying avian virus genes.

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Molecular Analysis of H7 Avian Influenza Viruses from Australia and New Zealand: Genetic Diversity and Relationships from 1976 to 2007

Journal of Virology ◽

10.1128/jvi.00930-10 ◽

2010 ◽

Vol 84 (19) ◽

pp. 9957-9966 ◽

Cited By ~ 25

Author(s):

Dieter Bulach ◽

Rebecca Halpin ◽

David Spiro ◽

Laura Pomeroy ◽

Daniel Janies ◽

...

Keyword(s):

New Zealand ◽

Avian Influenza ◽

Influenza A ◽

Influenza Viruses ◽

Full Genome Sequencing ◽

Influenza A Viruses ◽

Independent Evolution ◽

Avian Influenza A Virus ◽

Geographic Regions ◽

Genetic Pool

ABSTRACT Full-genome sequencing of 11 Australian and 1 New Zealand avian influenza A virus isolate (all subtype H7) has enabled comparison of the sequences of each of the genome segments to those of other subtype H7 avian influenza A viruses. The inference of phylogenetic relationships for each segment has been used to develop a model of the natural history of these viruses in Australia. Phylogenetic analysis of the hemagglutinin segment indicates that the Australian H7 isolates form a monophyletic clade. This pattern is consistent with the long-term, independent evolution that is, in this instance, associated with geographic regions. On the basis of the analysis of the other H7 hemagglutinin sequences, three other geographic regions for which similar monophyletic clades have been observed were confirmed. These regions are Eurasia plus Africa, North America, and South America. Analysis of the neuraminidase sequences from the H7N1, H7N3, and H7N7 genomes revealed the same region-based relationships. This pattern of independent evolution of Australian isolates is supported by the results of analysis of each of the six remaining genomic segments. These results, in conjunction with the occurrence of five different combinations of neuraminidase subtypes (H7N2, H7N3, H7N4, H7N6, H7N7) among the 11 Australian isolates, suggest that the maintenance host(s) is nearly exclusively associated with Australia. The single lineage of Australian H7 hemagglutinin sequences, despite the occurrence of multiple neuraminidase types, suggests the existence of a genetic pool from which a variety of reassortants arise rather than the presence of a small number of stable viral clones. This pattern of evolution is likely to occur in each of the regions mentioned above.

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Trade-offs between and within scales: environmental persistence and within-host fitness of avian influenza viruses

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2013.3051 ◽

2014 ◽

Vol 281 (1787) ◽

pp. 20133051 ◽

Cited By ~ 22

Author(s):

Andreas Handel ◽

Camille Lebarbenchon ◽

David Stallknecht ◽

Pejman Rohani

Keyword(s):

Avian Influenza ◽

Influenza A ◽

Influenza Viruses ◽

Viral Fitness ◽

Ecological Niches ◽

Influenza A Viruses ◽

Temperature Dependent ◽

Environmental Persistence ◽

Trade Off ◽

Trade Offs

Trade-offs between different components of a pathogen's replication and transmission cycle are thought to be common. A number of studies have identified trade-offs that emerge across scales, reflecting the tension between strategies that optimize within-host proliferation and large-scale population spread. Most of these studies are theoretical in nature, with direct experimental tests of such cross-scale trade-offs still rare. Here, we report an analysis of avian influenza A viruses across scales, focusing on the phenotype of temperature-dependent viral persistence. Taking advantage of a unique dataset that reports both environmental virus decay rates and strain-specific viral kinetics from duck challenge experiments, we show that the temperature-dependent environmental decay rate of a strain does not impact within-host virus load. Hence, for this phenotype, the scales of within-host infection dynamics and between-host environmental persistence do not seem to interact: viral fitness may be optimized on each scale without cross-scale trade-offs. Instead, we confirm the existence of a temperature-dependent persistence trade-off on a single scale, with some strains favouring environmental persistence in water at low temperatures while others reduce sensitivity to increasing temperatures. We show that this temperature-dependent trade-off is a robust phenomenon and does not depend on the details of data analysis. Our findings suggest that viruses might employ different environmental persistence strategies, which facilitates the coexistence of diverse strains in ecological niches. We conclude that a better understanding of the transmission and evolutionary dynamics of influenza A viruses probably requires empirical information regarding both within-host dynamics and environmental traits, integrated within a combined ecological and within-host framework.

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Complete Coding Sequences of One H9 and Three H7 Low-Pathogenic Influenza Viruses Circulating in Wild Birds in Belgium, 2009 to 2012

Genome Announcements ◽

10.1128/genomea.00540-16 ◽

2016 ◽

Vol 4 (3) ◽

Cited By ~ 2

Author(s):

Steven Van Borm ◽

Toon Rosseel ◽

Sylvie Marché ◽

Mieke Steensels ◽

Didier Vangeluwe ◽

...

Keyword(s):

Avian Influenza ◽

Illumina Sequencing ◽

Viral Genome ◽

Influenza A ◽

Wild Bird ◽

Influenza Viruses ◽

Influenza A Viruses ◽

Bird Population ◽

Coding Sequences ◽

Wild Waterfowl

The complete coding sequences of four avian influenza A viruses (two H7N7, one H7N1, and one H9N2) circulating in wild waterfowl in Belgium from 2009 to 2012 were determined using Illumina sequencing. All viral genome segments represent viruses circulating in the Eurasian wild bird population.

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The evolutionary dynamics of influenza A virus adaptation to mammalian hosts

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2012.0382 ◽

2013 ◽

Vol 368 (1614) ◽

pp. 20120382 ◽

Cited By ~ 27

Author(s):

S. Bhatt ◽

T. T. Lam ◽

S. J. Lycett ◽

A. J. Leigh Brown ◽

T. A. Bowden ◽

...

Keyword(s):

Avian Influenza ◽

Adaptive Evolution ◽

Influenza A ◽

Evolutionary Dynamics ◽

Adaptive Dynamics ◽

Swine Influenza ◽

Influenza Viruses ◽

Viral Fitness ◽

Influenza A Viruses ◽

Entire Genome

Few questions on infectious disease are more important than understanding how and why avian influenza A viruses successfully emerge in mammalian populations, yet little is known about the rate and nature of the virus’ genetic adaptation in new hosts. Here, we measure, for the first time, the genomic rate of adaptive evolution of swine influenza viruses (SwIV) that originated in birds. By using a curated dataset of more than 24 000 human and swine influenza gene sequences, including 41 newly characterized genomes, we reconstructed the adaptive dynamics of three major SwIV lineages (Eurasian, EA; classical swine, CS; triple reassortant, TR). We found that, following the transfer of the EA lineage from birds to swine in the late 1970s, EA virus genes have undergone substantially faster adaptive evolution than those of the CS lineage, which had circulated among swine for decades. Further, the adaptation rates of the EA lineage antigenic haemagglutinin and neuraminidase genes were unexpectedly high and similar to those observed in human influenza A. We show that the successful establishment of avian influenza viruses in swine is associated with raised adaptive evolution across the entire genome for many years after zoonosis, reflecting the contribution of multiple mutations to the coordinated optimization of viral fitness in a new environment. This dynamics is replicated independently in the polymerase genes of the TR lineage, which established in swine following separate transmission from non-swine hosts.

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Resurrected ancestral influenza A viruses recapitulate the avian-to-mammalian adaptation of European avian-like swine influenza virus

10.21203/rs.3.rs-436907/v1 ◽

2021 ◽

Author(s):

Wen Su ◽

Rhodri Harfoot ◽

Yvonne Su ◽

Jennifer DeBeauchamp ◽

Udayan Joseph ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Influenza A ◽

Swine Influenza Virus ◽

Swine Influenza ◽

Polymerase Activity ◽

Influenza Viruses ◽

Mammalian Host ◽

Influenza A Viruses ◽

Sequence Reconstruction

Abstract The emergence of a pandemic influenza virus may be better anticipated if we better understand the evolutionary steps taken by avian influenza viruses as they adapt to mammals. We used ancestral sequence reconstruction to resurrect viruses representing initial adaptive stages of the European avian-like H1N1 virus as it transitioned from avian to swine hosts. We demonstrate that efficient transmissibility in pigs was gained through stepwise adaptation after 1983. These time-dependent adaptations resulted in changes in hemagglutinin receptor binding specificity and increased viral polymerase activity. An NP-R351K mutation under strong positive selection increased the transmissibility of a reconstructed virus. The stepwise-adaptation of a wholly avian influenza virus to a mammalian host suggests a window where targeted intervention may have highest impact. Successful intervention will, however, require strategic coordination of surveillance and risk assessment activities to identify these adapting viruses and guide pandemic preparedness resources.

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Independence of Evolutionary and Mutational Rates after Transmission of Avian Influenza Viruses to Swine

Journal of Virology ◽

10.1128/jvi.73.3.1878-1884.1999 ◽

1999 ◽

Vol 73 (3) ◽

pp. 1878-1884 ◽

Cited By ~ 55

Author(s):

J. Stech ◽

X. Xiong ◽

C. Scholtissek ◽

R. G. Webster

Keyword(s):

New York ◽

Avian Influenza ◽

Influenza A ◽

Swine Influenza ◽

Influenza Viruses ◽

Mutation Rates ◽

Influenza A Viruses ◽

Species Barrier ◽

H1n1 Strain ◽

Serologic Evidence

ABSTRACT In 1979, an H1N1 avian influenza virus crossed the species barrier, establishing a new lineage in European swine. Because there is no direct or serologic evidence of previous H1N1 strains in these pigs, these isolates provide a model for studying early evolution of influenza viruses. The evolutionary rates of both the coding and noncoding changes of the H1N1 swine strains are higher than those of human and classic swine influenza A viruses. In addition, early H1N1 swine isolates show a marked plaque heterogeneity that consistently appears after a few passages. The presence of a mutator mutation was postulated (C. Scholtissek, S. Ludwig, and W. M. Fitch, Arch. Virol. 131:237–250, 1993) to account for these observations and the successful establishment of an avian H1N1 strain in swine. To address this question, we calculated the mutation rates of A/Mallard/New York/6750/78 (H2N2) and A/Swine/Germany/2/81 (H1N1) by using the frequency of amantadine-resistant mutants. To account for the inherent variability of estimated mutation rates, we used a probabilistic model for the statistical analysis. The resulting estimated mutation rates of the two strains were not significantly different. Therefore, an increased mutation rate due to the presence of a mutator mutation is unlikely to have led to the successful introduction of avian H1N1 viruses in European swine.

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Influenza A virus transmission: contributing factors and clinical implications

Expert Reviews in Molecular Medicine ◽

10.1017/s1462399410001705 ◽

2010 ◽

Vol 12 ◽

Cited By ~ 43

Author(s):

Jessica A. Belser ◽

Taronna R. Maines ◽

Terrence M. Tumpey ◽

Jacqueline M. Katz

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Influenza A ◽

Severe Disease ◽

Virus Transmission ◽

Influenza Viruses ◽

Clinical Implications ◽

Influenza A Viruses ◽

Molecular Features ◽

Efficient Transmission

Efficient human-to-human transmission is a necessary property for the generation of a pandemic influenza virus. To date, only influenza A viruses within the H1–H3 subtypes have achieved this capacity. However, sporadic cases of severe disease in individuals following infection with avian influenza A viruses over the past decade, and the emergence of a pandemic H1N1 swine-origin virus in 2009, underscore the need to better understand how influenza viruses acquire the ability to transmit efficiently. In this review, we discuss the biological constraints and molecular features known to affect virus transmissibility to and among humans. Factors influencing the behaviour of aerosols in the environment are described, and the mammalian models used to study virus transmission are presented. Recent progress in understanding the molecular determinants that confer efficient transmission has identified crucial roles for the haemagglutinin and polymerase proteins; nevertheless, influenza virus transmission remains a polygenic trait that is not completely understood. The clinical implications of this research, including methods currently under investigation to mitigate influenza virus human-to-human transmission, are discussed. A better understanding of the viral determinants necessary for efficient transmission will allow us to identify avian influenza viruses with pandemic potential.

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