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Sample records for influenza virus challenge

  1. Nonreplicating Influenza A Virus Vaccines Confer Broad Protection against Lethal Challenge

    PubMed Central

    Baz, Mariana; Boonnak, Kobporn; Paskel, Myeisha; Santos, Celia; Powell, Timothy; Townsend, Alain

    2015-01-01

    ABSTRACT New vaccine technologies are being investigated for their ability to elicit broadly cross-protective immunity against a range of influenza viruses. We compared the efficacies of two intranasally delivered nonreplicating influenza virus vaccines (H1 and H5 S-FLU) that are based on the suppression of the hemagglutinin signal sequence, with the corresponding H1N1 and H5N1 cold-adapted (ca) live attenuated influenza virus vaccines in mice and ferrets. Administration of two doses of H1 or H5 S-FLU vaccines protected mice and ferrets from lethal challenge with homologous, heterologous, and heterosubtypic influenza viruses, and two doses of S-FLU and ca vaccines yielded comparable effects. Importantly, when ferrets immunized with one dose of H1 S-FLU or ca vaccine were challenged with the homologous H1N1 virus, the challenge virus failed to transmit to naive ferrets by the airborne route. S-FLU technology can be rapidly applied to any emerging influenza virus, and the promising preclinical data support further evaluation in humans. PMID:26489862

  2. Continuing challenges in influenza

    PubMed Central

    Webster, Robert G.; Govorkova, Elena A.

    2014-01-01

    Influenza is an acute respiratory disease in mammals and domestic poultry that emerges from zoonotic reservoirs in aquatic birds and bats. Although influenza viruses are among the most intensively studied pathogens, existing control options require further improvement. Influenza vaccines must be regularly updated because of continuous antigenic drift and sporadic antigenic shifts in the viral surface glycoproteins. Currently, influenza therapeutics are limited to neuraminidase inhibitors; novel drugs and vaccine approaches are therefore urgently needed. Advances in vaccinology and structural analysis have revealed common antigenic epitopes on hemagglutinins across all influenza viruses and suggest that a universal influenza vaccine is possible. In addition, various immunomodulatory agents and signaling pathway inhibitors are undergoing preclinical development. Continuing challenges in influenza include the emergence of pandemic H1N1 influenza in 2009, human infections with avian H7N9 influenza in 2013, and sporadic human cases of highly pathogenic avian H5N1 influenza. Here, we review the challenges facing influenza scientists and veterinary and human public health officials; we also discuss the exciting possibility of achieving the ultimate goal of controlling influenza’s ability to change its antigenicity. PMID:24891213

  3. Immunization by vaccine-coated microneedle arrays protects against lethal influenza virus challenge

    PubMed Central

    Zhu, Qiyun; Zarnitsyn, Vladimir G.; Ye, Ling; Wen, Zhiyuan; Gao, Yulong; Pan, Lei; Skountzou, Ioanna; Gill, Harvinder S.; Prausnitz, Mark R.; Yang, Chinglai; Compans, Richard W.

    2009-01-01

    Influenza prophylaxis would benefit from a simple method to administer influenza vaccine into skin without the need for hypodermic needles. In this study, solid metal microneedle arrays (MNs) were investigated as a system for cutaneous vaccine delivery using influenza virus antigen. The MNs with 5 monument-shaped microneedles per array were produced and coated with inactivated influenza virus A/PR/8/34 (IIV). As much as 10 μg of viral proteins could be coated onto an array of 5 microneedles, and the coated IIV was delivered into skin at high efficiency within minutes. The coated MNs were used to immunize mice in comparison with conventional intramuscular injection at the same dose. Analysis of immune responses showed that a single immunization with IIV-coated MNs induced strong antibody responses against influenza virus, with significant levels of hemagglutination inhibition activities (>1:40), which were comparable to those induced by conventional intramuscular immunization. Moreover, mice immunized by a single dose of IIV coated on MNs were effectively protected against lethal challenge by a high dose of mouse-adapted influenza virus A/PR/8/34. These results show that MNs are highly effective as a simple method of vaccine delivery to elicit protective immune responses against virus infection. PMID:19416832

  4. Immunization of Pigs with a Particle-Mediated DNA Vaccine to Influenza A Virus Protects against Challenge with Homologous Virus

    PubMed Central

    Macklin, Michael D.; McCabe, Dennis; McGregor, Martha W.; Neumann, Veronica; Meyer, Todd; Callan, Robert; Hinshaw, Virginia S.; Swain, William F.

    1998-01-01

    Particle-mediated delivery of a DNA expression vector encoding the hemagglutinin (HA) of an H1N1 influenza virus (A/Swine/Indiana/1726/88) to porcine epidermis elicits a humoral immune response and accelerates the clearance of virus in pigs following a homotypic challenge. Mucosal administration of the HA expression plasmid elicits an immune response that is qualitatively different than that elicited by the epidermal vaccination in terms of inhibition of the initial virus infection. In contrast, delivery of a plasmid encoding an influenza virus nucleoprotein from A/PR/8/34 (H1N1) to the epidermis elicits a strong humoral response but no detectable protection in terms of nasal virus shed. The efficacy of the HA DNA vaccine was compared with that of a commercially available inactivated whole-virus vaccine as well as with the level of immunity afforded by previous infection. The HA DNA and inactivated viral vaccines elicited similar protection in that initial infection was not prevented, but subsequent amplification of the infection is limited, resulting in early clearance of the virus. Convalescent animals which recovered from exposure to virulent swine influenza virus were completely resistant to infection when challenged. The porcine influenza A virus system is a relevant preclinical model for humans in terms of both disease and gene transfer to the epidermis and thus provides a basis for advancing the development of DNA-based vaccines. PMID:9445052

  5. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

    Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection. PMID:27486731

  6. [Influenza virus].

    PubMed

    Juozapaitis, Mindaugas; Antoniukas, Linas

    2007-01-01

    Every year, especially during the cold season, many people catch an acute respiratory disease, namely flu. It is easy to catch this disease; therefore, it spreads very rapidly and often becomes an epidemic or a global pandemic. Airway inflammation and other body ailments, which form in a very short period, torment the patient several weeks. After that, the symptoms of the disease usually disappear as quickly as they emerged. The great epidemics of flu have rather unique characteristics; therefore, it is possible to identify descriptions of such epidemics in historic sources. Already in the 4th century bc, Hippocrates himself wrote about one of them. It is known now that flu epidemics emerge rather frequently, but there are no regular intervals between those events. The epidemics can differ in their consequences, but usually they cause an increased mortality of elderly people. The great flu epidemics of the last century took millions of human lives. In 1918-19, during "The Spanish" pandemic of flu, there were around 40-50 millions of deaths all over the world; "Pandemic of Asia" in 1957 took up to one million lives, etc. Influenza virus can cause various disorders of the respiratory system: from mild inflammations of upper airways to acute pneumonia that finally results in the patient's death. Scientist Richard E. Shope, who investigated swine flu in 1920, had a suspicion that the cause of this disease might be a virus. Already in 1933, scientists from the National Institute for Medical Research in London - Wilson Smith, Sir Christopher Andrewes, and Sir Patrick Laidlaw - for the first time isolated the virus, which caused human flu. Then scientific community started the exhaustive research of influenza virus, and the great interest in this virus and its unique features is still active even today. PMID:18182834

  7. Influenza A Virus Challenge Models in Cynomolgus Macaques Using the Authentic Inhaled Aerosol and Intra-Nasal Routes of Infection.

    PubMed

    Marriott, Anthony C; Dennis, Mike; Kane, Jennifer A; Gooch, Karen E; Hatch, Graham; Sharpe, Sally; Prevosto, Claudia; Leeming, Gail; Zekeng, Elsa-Gayle; Staples, Karl J; Hall, Graham; Ryan, Kathryn A; Bate, Simon; Moyo, Nathifa; Whittaker, Catherine J; Hallis, Bassam; Silman, Nigel J; Lalvani, Ajit; Wilkinson, Tom M; Hiscox, Julian A; Stewart, James P; Carroll, Miles W

    2016-01-01

    Non-human primates are the animals closest to humans for use in influenza A virus challenge studies, in terms of their phylogenetic relatedness, physiology and immune systems. Previous studies have shown that cynomolgus macaques (Macaca fascicularis) are permissive for infection with H1N1pdm influenza virus. These studies have typically used combined challenge routes, with the majority being intra-tracheal delivery, and high doses of virus (> 107 infectious units). This paper describes the outcome of novel challenge routes (inhaled aerosol, intra-nasal instillation) and low to moderate doses (103 to 106 plaque forming units) of H1N1pdm virus in cynomolgus macaques. Evidence of virus replication and sero-conversion were detected in all four challenge groups, although the disease was sub-clinical. Intra-nasal challenge led to an infection confined to the nasal cavity. A low dose (103 plaque forming units) did not lead to detectable infectious virus shedding, but a 1000-fold higher dose led to virus shedding in all intra-nasal challenged animals. In contrast, aerosol and intra-tracheal challenge routes led to infections throughout the respiratory tract, although shedding from the nasal cavity was less reproducible between animals compared to the high-dose intra-nasal challenge group. Intra-tracheal and aerosol challenges induced a transient lymphopaenia, similar to that observed in influenza-infected humans, and greater virus-specific cellular immune responses in the blood were observed in these groups in comparison to the intra-nasal challenge groups. Activation of lung macrophages and innate immune response genes was detected at days 5 to 7 post-challenge. The kinetics of infection, both virological and immunological, were broadly in line with human influenza A virus infections. These more authentic infection models will be valuable in the determination of anti-influenza efficacy of novel entities against less severe (and thus more common) influenza infections. PMID

  8. Influenza A Virus Challenge Models in Cynomolgus Macaques Using the Authentic Inhaled Aerosol and Intra-Nasal Routes of Infection

    PubMed Central

    Marriott, Anthony C.; Dennis, Mike; Kane, Jennifer A.; Gooch, Karen E.; Hatch, Graham; Sharpe, Sally; Prevosto, Claudia; Leeming, Gail; Zekeng, Elsa-Gayle; Staples, Karl J.; Hall, Graham; Ryan, Kathryn A.; Bate, Simon; Moyo, Nathifa; Whittaker, Catherine J.; Hallis, Bassam; Silman, Nigel J.; Lalvani, Ajit; Wilkinson, Tom M.; Hiscox, Julian A.; Stewart, James P.; Carroll, Miles W.

    2016-01-01

    Non-human primates are the animals closest to humans for use in influenza A virus challenge studies, in terms of their phylogenetic relatedness, physiology and immune systems. Previous studies have shown that cynomolgus macaques (Macaca fascicularis) are permissive for infection with H1N1pdm influenza virus. These studies have typically used combined challenge routes, with the majority being intra-tracheal delivery, and high doses of virus (> 107 infectious units). This paper describes the outcome of novel challenge routes (inhaled aerosol, intra-nasal instillation) and low to moderate doses (103 to 106 plaque forming units) of H1N1pdm virus in cynomolgus macaques. Evidence of virus replication and sero-conversion were detected in all four challenge groups, although the disease was sub-clinical. Intra-nasal challenge led to an infection confined to the nasal cavity. A low dose (103 plaque forming units) did not lead to detectable infectious virus shedding, but a 1000-fold higher dose led to virus shedding in all intra-nasal challenged animals. In contrast, aerosol and intra-tracheal challenge routes led to infections throughout the respiratory tract, although shedding from the nasal cavity was less reproducible between animals compared to the high-dose intra-nasal challenge group. Intra-tracheal and aerosol challenges induced a transient lymphopaenia, similar to that observed in influenza-infected humans, and greater virus-specific cellular immune responses in the blood were observed in these groups in comparison to the intra-nasal challenge groups. Activation of lung macrophages and innate immune response genes was detected at days 5 to 7 post-challenge. The kinetics of infection, both virological and immunological, were broadly in line with human influenza A virus infections. These more authentic infection models will be valuable in the determination of anti-influenza efficacy of novel entities against less severe (and thus more common) influenza infections. PMID

  9. Challenge of Pigs with Natural Immunity to H1 and H3 Swine Influenza Virus with Pandemic 2009 H1N1 Influenza Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction. The emergence of the pandemic 2009 human H1N1 influenza A virus raised many questions about the implications for this virus in swine (1). One such question is, does prior exposure to influenza virus confer any protection against the new virus? This report describes a study to evaluate ...

  10. Avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is type A influenza, which is adapted to an avian host. Although avian influenza has been isolated from numerous avian species, the primary natural hosts for the virus are dabbling ducks, shorebirds, and gulls. The virus can be found world-wide in these species and in o...

  11. Single-Domain Antibodies Targeting Neuraminidase Protect against an H5N1 Influenza Virus Challenge

    PubMed Central

    Cardoso, Francisco Miguel; Ibañez, Lorena Itatí; Van den Hoecke, Silvie; De Baets, Sarah; Smet, Anouk; Roose, Kenny; Schepens, Bert; Descamps, Francis J.; Fiers, Walter; Muyldermans, Serge

    2014-01-01

    ABSTRACT Influenza virus neuraminidase (NA) is an interesting target of small-molecule antiviral drugs. We isolated a set of H5N1 NA-specific single-domain antibodies (N1-VHHm) and evaluated their in vitro and in vivo antiviral potential. Two of them inhibited the NA activity and in vitro replication of clade 1 and 2 H5N1 viruses. We then generated bivalent derivatives of N1-VHHm by two methods. First, we made N1-VHHb by genetically joining two N1-VHHm moieties with a flexible linker. Second, bivalent N1-VHH-Fc proteins were obtained by genetic fusion of the N1-VHHm moiety with the crystallizable region of mouse IgG2a (Fc). The in vitro antiviral potency against H5N1 of both bivalent N1-VHHb formats was 30- to 240-fold higher than that of their monovalent counterparts, with 50% inhibitory concentrations in the low nanomolar range. Moreover, single-dose prophylactic treatment with bivalent N1-VHHb or N1-VHH-Fc protected BALB/c mice against a lethal challenge with H5N1 virus, including an oseltamivir-resistant H5N1 variant. Surprisingly, an N1-VHH-Fc fusion without in vitro NA-inhibitory or antiviral activity also protected mice against an H5N1 challenge. Virus escape selection experiments indicated that one amino acid residue close to the catalytic site is required for N1-VHHm binding. We conclude that single-domain antibodies directed against influenza virus NA protect against H5N1 virus infection, and when engineered with a conventional Fc domain, they can do so in the absence of detectable NA-inhibitory activity. IMPORTANCE Highly pathogenic H5N1 viruses are a zoonotic threat. Outbreaks of avian influenza caused by these viruses occur in many parts of the world and are associated with tremendous economic loss, and these viruses can cause very severe disease in humans. In such cases, small-molecule inhibitors of the viral NA are among the few treatment options for patients. However, treatment with such drugs often results in the emergence of resistant viruses

  12. Lymphocyte responses in the lungs of vaccinated pigs following homologous and heterologous influenza A virus challenge.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccine associated enhanced respiratory disease (VAERD) has been described in pigs vaccinated with whole-inactivated influenza virus (WIV) following infection with heterologous influenza A virus (IAV). WIV vaccination elicits production of non-neutralizing antibody that is cross-reactive to the chal...

  13. Protective efficacy of low-dose amantadine in adults challenged with wild-type influenza A virus.

    PubMed Central

    Sears, S D; Clements, M L

    1987-01-01

    The prophylactic efficacy of a low dose (100 mg) of amantadine hydrochloride against experimental challenge with influenza A/Texas/1/85 (H1N1) wild-type virus was determined in healthy adult volunteers in a placebo-controlled, double-blind, randomized trial. No side effects of the 100-mg dose were observed in the amantadine-treated volunteers. Compared with placebo, 100 mg of amantadine significantly reduced the frequency of illness (9 of 22 versus 2 of 22 volunteers, P less than 0.04) and provided 78% protection against influenza illness. The two ill volunteers in the amantadine group had rhinitis only, whereas most of the ill placebo controls developed both systemic and upper-respiratory-tract illness. Wild-type virus was recovered from 50% of the amantadine-treated volunteers, compared with 82% of the placebo controls. Of note, the infected amantadine recipients shed 100 times less virus and shed virus for half as many days as did the infected placebo recipients. Although amantadine restricted viral replication, it did not interfere with the development of an antibody response to influenza virus. These results indicate that in adults experimentally challenged with influenza wild-type virus, 100 mg of amantadine is effective both in the prevention of influenza illness and in the restriction of virus replication. PMID:3435099

  14. Lung Irradiation Increases Mortality After Influenza A Virus Challenge Occurring Late After Exposure

    SciTech Connect

    Manning, Casey M.; Johnston, Carl J.; Reed, Christina K.; Lawrence, B. Paige; Williams, Jacqueline P.; Finkelstein, Jacob N.

    2013-05-01

    Purpose: To address whether irradiation-induced changes in the lung environment alter responses to a viral challenge delivered late after exposure but before the appearance of late lung radiation injury. Methods and Materials: C57BL/6J mice received either lung alone or combined lung and whole-body irradiation (0-15 Gy). At 10 weeks after irradiation, animals were infected with 120 HAU influenza virus strain A/HKx31. Innate and adaptive immune cell recruitment was determined using flow cytometry. Cytokine and chemokine production and protein leakage into the lung after infection were assessed. Results: Prior irradiation led to a dose-dependent failure to regain body weight after infection and exacerbated mortality, but it did not affect virus-specific immune responses or virus clearance. Surviving irradiated animals displayed a persistent increase in total protein in bronchoalveolar lavage fluid and edema. Conclusions: Lung irradiation increased susceptibility to death after infection with influenza virus and impaired the ability to complete recovery. This altered response does not seem to be due to a radiation effect on the immune response, but it may possibly be an effect on epithelial repair.

  15. Comparison of the effectiveness of antibody and cell-mediated immunity against inhaled and instilled influenza virus challenge

    PubMed Central

    2013-01-01

    Background To evaluate immunity against influenza, mouse challenge studies are typically performed by intranasal instillation of a virus suspension to anesthetized animals. This results in an unnatural environment in the lower respiratory tract during infection, and therefore there is some concern that immune mechanisms identified in this model may not reflect those that protect against infectious virus particles delivered directly to the lower respiratory tract as an aerosol. Method To evaluate differences in protection against instilled and inhaled virus, mice were immunized with influenza antigens known to induce antibody or cell-mediated responses and then challenged with 100 LD50 A/PR/8/34 (PR8) in the form of aerosol (inhaled) or liquid suspension (instilled). Results Mice immunized with recombinant adenovirus (Ad) expressing hemagglutinin were protected against weight loss and death in both challenge models, however immunization with Ad expressing nucleoprotein of influenza A (NPA) or M2 resulted in greater protection against inhaled aerosolized virus than virus instilled in liquid suspension. Ad-M2, but not Ad-NPA-immunized mice were protected against a lower instillation challenge dose. Conclusions These results demonstrate differences in protection that are dependent on challenge method, and suggest that cell-mediated immunity may be more accurately demonstrated in mouse inhalation studies. Furthermore, the data suggest immune mechanisms generally characterized as incomplete or weak in mouse models using liquid intranasal challenge may offer greater immunity against influenza infection than previously thought. PMID:23777453

  16. Towards a universal influenza vaccine: volunteer virus challenge studies in quarantine to speed the development and subsequent licensing

    PubMed Central

    Oxford, John S

    2013-01-01

    There are now more than 5 experimental vaccine formulations which induce T and B cell immunity towards the internally situated virus proteins matrix (M1 and M2e) and nucleoprotein (NP), and towards stem and stalk regions of the HA which have a shared antigenic structure amongst many of the 17 influenza A virus sub types. Such ‘universal vaccines’ could be used, at least in theory, as a prophylactic stockpile vaccine for newly emerged epidemic and novel pandemic influenza A viruses or as a supplement to conventional HA/NA vaccines. My own laboratory has approached the problem from the clinical viewpoint by identifying CD4+ cells which are present in influenza infected volunteers who resist influenza infection. We have established precisely which peptides in M and NP proteins react with these immune CD4 cells. These experimental vaccines induce immunity in animal models but with a single exception no data have been published on protection against influenza virus infection in humans. The efficacy of the latter vaccine is based on vaccinia virus (MVA) as a carrier and was analyzed in a quarantine unit. Given the absence of induced HI antibody in the new universal vaccines a possible licensing strategy is a virus challenge model in quarantine whereby healthy volunteers can be immunized with the new vaccine and thereafter deliberately infected and clinical signs recorded alongside quantities of virus excreted and compared with unvaccinated controls. PMID:23617282

  17. Recombinant Newcastle disease virus expressing H9 HA protects chickens against heterologous avian influenza H9N2 virus challenge.

    PubMed

    Nagy, Abdou; Lee, Jinhwa; Mena, Ignacio; Henningson, Jamie; Li, Yuhao; Ma, Jingjiao; Duff, Michael; Li, Yonghai; Lang, Yuekun; Yang, Jianmei; Abdallah, Fatma; Richt, Juergen; Ali, Ahmed; García-Sastre, Adolfo; Ma, Wenjun

    2016-05-17

    In order to produce an efficient poultry H9 avian influenza vaccine that provides cross-protection against multiple H9 lineages, two Newcastle disease virus (NDV) LaSota vaccine strain recombinant viruses were generated using reverse genetics. The recombinant NDV-H9Con virus expresses a consensus-H9 hemagglutinin (HA) that is designed based on available H9N2 sequences from Chinese and Middle Eastern isolates. The recombinant NDV-H9Chi virus expresses a chimeric-H9 HA in which the H9 ectodomain of A/Guinea Fowl/Hong Kong/WF10/99 was fused with the cytoplasmic and transmembrane domain of the fusion protein (F) of NDV. Both recombinant viruses expressed the inserted HA stably and grew to high titers. An efficacy study in chickens showed that both recombinant viruses were able to provide protection against challenge with a heterologous H9N2 virus. In contrast to the NDV-H9Chi virus, the NDV-H9Con virus induced a higher hemagglutination inhibition titer against both NDV and H9 viruses in immunized birds, and efficiently inhibited virus shedding through the respiratory route. Moreover, sera collected from birds immunized with either NDV-H9Con or NDV-H9Chi were able to cross-neutralize two different lineages of H9N2 viruses, indicating that NDV-H9Con and NDV-H9Chi are promising vaccine candidates that could provide cross-protection among different H9N2 lineage viruses. PMID:27102817

  18. Adenovirus-mediated artificial MicroRNAs targeting matrix or nucleoprotein genes protect mice against lethal influenza virus challenge.

    PubMed

    Zhang, H; Tang, X; Zhu, C; Song, Y; Yin, J; Xu, J; Ertl, H C J; Zhou, D

    2015-08-01

    Influenza virus (IV) infection is a major public health problem, causing millions of cases of severe illness and as many as 500 000 deaths each year worldwide. Given the limitations of current prevention or treatment of acute influenza, novel therapies are needed. RNA interference (RNAi) through microRNAs (miRNA) is an emerging technology that can suppress virus replication in vitro and in vivo. Here, we describe a novel strategy for the treatment of infuenza based on RNAi delivered by a replication-defective adenovirus (Ad) vector, derived from chimpanzee serotype 68 (AdC68). Our results showed that artificial miRNAs (amiRNAs) specifically targeting conserved regions of the IV genome could effectively inhibit virus replication in human embryonic kidney 293 cells. Moreover, our results demonstrated that prophylactic treatment with AdC68 expressing amiRNAs directed against M1, M2 or nucleoprotein genes of IV completely protected mice from homologous A/PR8 virus challenge and partially protected the mice from heterologous influenza A virus strains such as H9N2 and H5N1. Collectively, our data demonstrate that amiRNAs targeting the conserved regions of influenza A virus delivered by Ad vectors should be pursued as a novel strategy for prophylaxis of IV infection in humans and animals. PMID:25835311

  19. Strategies and challenges for eliciting immunity against avian influenza virus in birds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccines and vaccination have emerged during the past two decades as essential tools in avian influenza (AI) control for poultry because they: increase resistance to infection, prevent illness and death, reduce virus replication and shed from respiratory and alimentary tracts, and reduce virus trans...

  20. Towards a universal vaccine for avian influenza: protective efficacy of modified Vaccinia virus Ankara and Adenovirus vaccines expressing conserved influenza antigens in chickens challenged with low pathogenic avian influenza virus.

    PubMed

    Boyd, Amy C; Ruiz-Hernandez, Raul; Peroval, Marylene Y; Carson, Connor; Balkissoon, Devanand; Staines, Karen; Turner, Alison V; Hill, Adrian V S; Gilbert, Sarah C; Butter, Colin

    2013-01-11

    Current vaccines targeting surface proteins can drive antigenic variation resulting either in the emergence of more highly pathogenic viruses or of antigenically distinct viruses that escape control by vaccination and thereby persist in the host population. Influenza vaccines typically target the highly mutable surface proteins and do not provide protection against heterologous challenge. Vaccines which induce immune responses against conserved influenza epitopes may confer protection against heterologous challenge. We report here the results of vaccination with recombinant modified Vaccinia virus Ankara (MVA) and Adenovirus (Ad) expressing a fusion construct of nucleoprotein and matrix protein (NP+M1). Prime and boost vaccination regimes were trialled in different ages of chicken and were found to be safe and immunogenic. Interferon-γ (IFN-γ) ELISpot was used to assess the cellular immune response post secondary vaccination. In ovo Ad prime followed by a 4 week post hatch MVA boost was identified as the most immunogenic regime in one outbred and two inbred lines of chicken. Following vaccination, one inbred line (C15I) was challenged with low pathogenic avian influenza (LPAI) H7N7 (A/Turkey/England/1977). Birds receiving a primary vaccination with Ad-NP+M1 and a secondary vaccination with MVA-NP+M1 exhibited reduced cloacal shedding as measured by plaque assay at 7 days post infection compared with birds vaccinated with recombinant viruses containing irrelevant antigen. This preliminary indication of efficacy demonstrates proof of concept in birds; induction of T cell responses in chickens by viral vectors containing internal influenza antigens may be a productive strategy for the development of vaccines to induce heterologous protection against influenza in poultry. PMID:23200938

  1. Influenza A virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A viruses are important veterinary and human health pathogens around the world. Avian influenza (AI) virus in poultry is unusual in that it can cause a range of disease symptoms from a subclinical infection to being highly virulent with 100% mortality. The difference between low pathogen...

  2. INFLUENZA VIRUS IN POULTRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is normally found in wild birds, particularly in ducks and shorebirds, where it does not cause any perceptible clinical disease. However, poultry, including chickens and turkeys, are not normal hosts for avian influenza, but if the virus is introduced it can result in mi...

  3. Primary pulmonary cytotoxic T lymphocytes induced by immunization with a vaccinia virus recombinant expressing influenza A virus nucleoprotein peptide do not protect mice against challenge.

    PubMed

    Lawson, C M; Bennink, J R; Restifo, N P; Yewdell, J W; Murphy, B R

    1994-06-01

    The nucleoprotein (NP) of influenza A virus is the dominant antigen recognized by influenza virus-specific cytotoxic T lymphocytes (CTLs), and adoptive transfer of NP-specific CTLs protects mice from influenza A virus infection. BALB/c mouse cells (H-2d) recognize a single Kd-restricted CTL epitope of NP consisting of amino acids 147 to 155. In the present study, mice were immunized with various vaccinia virus recombinant viruses to examine the effect of the induction of primary pulmonary CTLs on resistance to challenge with influenza A/Puerto Rico/8/34 virus. The minigene ESNP(147-155)-VAC construct, composed of a signal sequence from the adenovirus E3/19K glycoprotein (designated ES) and expressing the 9-amino-acid NP natural determinant (amino acids 147 to 155) preceded by an alanine residue, a similar minigene NP(Met 147-155)-VAC lacking ES, and a full-length NP-VAC recombinant of influenza virus were analyzed. The two minigene NP-VAC recombinants induced a greater primary pulmonary CTL response than the full-length NP-VAC recombinant. However, NP-specific CTLs induced by immunization with ESNP(147-155)-VAC did not decrease peak virus titer or accelerate clearance of virus in the lungs of mice challenged intranasally with A/PR/8/34. Furthermore, NP-specific CTLs induced by immunization did not protect mice challenged intranasally with a lethal dose of A/PR/8/34. Sequence analysis of the NP CTL epitope of A/PR/8/34 challenge virus obtained from lungs after 8 days of replication in ESNP(147-155)-VAC-immunized mice showed identity with that of the input virus, demonstrating that an escape mutant had not emerged during replication in vivo. Thus, in contrast to adoptively transferred CTLs, pulmonary NP-specific CTLs induced by recombinant vaccinia virus immunization do not have protective in vivo antiviral activity against influenza virus infection. PMID:7514677

  4. Mucosal administration of raccoonpox virus expressing highly pathogenic avian H5N1 influenza neuraminidase is highly protective against H5N1 and seasonal influenza virus challenge.

    PubMed

    Kingstad-Bakke, Brock; Kamlangdee, Attapon; Osorio, Jorge E

    2015-09-22

    We previously generated recombinant poxviruses expressing influenza antigens and studied their efficacy as potential highly pathogenic avian influenza (HPAI) vaccines in mice. While both modified vaccinia Ankara (MVA) and raccoon poxvirus (RCN) expressing hemagglutinin (HA) provided strong protection when administered by parenteral routes, only RCN-neuraminidase (NA) showed promise as a mucosal vaccine. In the present study we evaluated the efficacy of RCN-NA constructs by both intradermal (ID) and intranasal (IN) routes. Surprisingly, while RCN-NA completely protected mice when administered by the IN route, it failed to protect mice when administered by the ID route. After challenge, significantly less virus induced pathology was observed in the lungs of mice vaccinated with RCN-NA by the IN route as compared to the ID route. Furthermore, IN administration of RCN-NA elicited neutralizing antibodies detected in bronchoalveolar lavage (BAL) samples. We also determined the role of cellular immune responses in protection elicited by RCN-NA by depleting CD4 and CD8 T cells prior to challenge. Finally, we demonstrated for the first time that antibodies against NA can block viral entry in addition to viral spread in vitro. These studies demonstrate the importance of mucosal administration of RCN viral vectors for eliciting protective immune responses against the NA antigen. PMID:26271828

  5. Adenovirus vectored vaccines against influenza a virus do not result in vaccine associated enhanced respiratory disease following heterologous challenge in contrast to whole inactivated virus vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heterologous influenza A virus (IAV) challenge following vaccination with an intramuscular (IM) whole inactivated vaccine (WIV) can result in vaccine-associated enhanced respiratory disease (VAERD). The objective of this study was to use an adenovirus (Ad5) vector vaccine platform that expressed IAV...

  6. Analytical technologies for influenza virus-like particle candidate vaccines: challenges and emerging approaches

    PubMed Central

    2013-01-01

    Influenza virus-like particle vaccines are one of the most promising ways to respond to the threat of future influenza pandemics. VLPs are composed of viral antigens but lack nucleic acids making them non-infectious which limit the risk of recombination with wild-type strains. By taking advantage of the advancements in cell culture technologies, the process from strain identification to manufacturing has the potential to be completed rapidly and easily at large scales. After closely reviewing the current research done on influenza VLPs, it is evident that the development of quantification methods has been consistently overlooked. VLP quantification at all stages of the production process has been left to rely on current influenza quantification methods (i.e. Hemagglutination assay (HA), Single Radial Immunodiffusion assay (SRID), NA enzymatic activity assays, Western blot, Electron Microscopy). These are analytical methods developed decades ago for influenza virions and final bulk influenza vaccines. Although these methods are time-consuming and cumbersome they have been sufficient for the characterization of final purified material. Nevertheless, these analytical methods are impractical for in-line process monitoring because VLP concentration in crude samples generally falls out of the range of detection for these methods. This consequently impedes the development of robust influenza-VLP production and purification processes. Thus, development of functional process analytical techniques, applicable at every stage during production, that are compatible with different production platforms is in great need to assess, optimize and exploit the full potential of novel manufacturing platforms. PMID:23642219

  7. An influenza D virus vaccine protects cattle from respiratory disease caused by homologous challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Originally isolated from swine, the proposed influenza D virus has since been shown to be common in cattle. Inoculation of IDV to naïve calves resulted in mild respiratory disease histologically characterized by tracheitis. As several studies have associated the presence of IDV with acute bovine r...

  8. H7 avian influenza virus vaccines protect chickens against challenge with antigenically diverse isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination has been a critical tool in the control of some avian influenza viruses (AIV) and has been used routinely in Pakistan to help control sporadic outbreaks of highly pathogenic (HP) H7 AIV since 1995. During that time, several AIV isolates were utilized as inactivated vaccines with varying...

  9. MVA Vectors Expressing Conserved Influenza Proteins Protect Mice against Lethal Challenge with H5N1, H9N2 and H7N1 Viruses

    PubMed Central

    Hessel, Annett; Savidis-Dacho, Helga; Coulibaly, Sogue; Portsmouth, Daniel; Kreil, Thomas R.; Crowe, Brian A.; Schwendinger, Michael G.; Pilz, Andreas; Barrett, P. Noel; Falkner, Falko G.; Schäfer, Birgit

    2014-01-01

    Background The availability of a universal influenza vaccine able to induce broad cross-reactive immune responses against diverse influenza viruses would provide an alternative to currently available strain-specific vaccines. We evaluated the ability of vectors based on modified vaccinia virus Ankara (MVA) expressing conserved influenza proteins to protect mice against lethal challenge with multiple influenza subtypes. Methods Mice were immunized with MVA vectors expressing H5N1-derived nucleoprotein (NP), the stem region of hemagglutinin (HA), matrix proteins 1 and 2 (M1 and M2), the viral polymerase basic protein 1 (PB1), or the HA stem fused to a quadrivalent matrix protein 2 extracellular domain (M2e). Immunized mice were challenged with lethal doses of H5N1, H7N1 or H9N2 virus and monitored for disease symptoms and weight loss. To investigate the influence of previous exposure to influenza virus on protective immune responses induced by conserved influenza proteins, mice were infected with pandemic H1N1 virus (H1N1pdm09) prior to immunization and subsequently challenged with H5N1 virus. Antibody and T cell responses were assessed by ELISA and flow cytometry, respectively. Results MVA vectors expressing NP alone, or co-expressed with other conserved influenza proteins, protected mice against lethal challenge with H5N1, H7N1 or H9N2 virus. Pre-exposure to H1N1pdm09 increased protective efficacy against lethal H5N1 challenge. None of the other conserved influenza proteins provided significant levels of protection against lethal challenge. NP-expressing vectors induced high numbers of influenza-specific CD4+ and CD8+ T cells and high titer influenza-specific antibody responses. Higher influenza-specific CD4+ T cell responses and NP-specific CD8+ T cell responses were associated with increased protective efficacy. Conclusions MVA vectors expressing influenza NP protect mice against lethal challenge with H5N1, H7N1 and H9N2 viruses by a mechanism involving influenza

  10. Immunologic Characterization of a Rhesus Macaque H1N1 Challenge Model for Candidate Influenza Virus Vaccine Assessment

    PubMed Central

    Skinner, Jason A.; Zurawski, Sandra M.; Sugimoto, Chie; Vinet-Oliphant, Heather; Vinod, Parvathi; Xue, Yaming; Russell-Lodrigue, Kasi; Albrecht, Randy A.; García-Sastre, Adolfo; Salazar, Andres M.; Roy, Chad J.; Kuroda, Marcelo J.; Oh, SangKon

    2014-01-01

    Despite the availability of annually formulated vaccines, influenza virus infection remains a worldwide public health burden. Therefore, it is important to develop preclinical challenge models that enable the evaluation of vaccine candidates while elucidating mechanisms of protection. Here, we report that naive rhesus macaques challenged with 2009 pandemic H1N1 (pH1N1) influenza virus do not develop observable clinical symptoms of disease but develop a subclinical biphasic fever on days 1 and 5 to 6 postchallenge. Whole blood microarray analysis further revealed that interferon activity was associated with fever. We then tested whether type I interferon activity in the blood is a correlate of vaccine efficacy. The animals immunized with candidate vaccines carrying hemagglutinin (HA) or nucleoprotein (NP) exhibited significantly reduced interferon activity on days 5 to 6 postchallenge. Supported by cellular and serological data, we conclude that blood interferon activity is a prominent marker that provides a convenient metric of influenza virus vaccine efficacy in the subclinical rhesus macaque model. PMID:25298110

  11. Enhanced pneumonia and disease in pigs vaccinated with an inactivated human-like (delta-cluster) H1N2 vaccine and challenged with pandemic 2009 H1N1 influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza is an economically important respiratory disease affecting swine world-wide with potential zoonotic implications. Genetic reassortment and drift has resulted in genetically and antigenically distinct swine influenza viruses (SIVs). Consequently, prevention of SIV infection is challenging ...

  12. Incorporation of membrane-bound, mammalian-derived immunomodulatory proteins into influenza whole virus vaccines boosts immunogenicity and protection against lethal challenge

    PubMed Central

    Herbert, Andrew S; Heffron, Lynn; Sundick, Roy; Roberts, Paul C

    2009-01-01

    Background Influenza epidemics continue to cause morbidity and mortality within the human population despite widespread vaccination efforts. This, along with the ominous threat of an avian influenza pandemic (H5N1), demonstrates the need for a much improved, more sophisticated influenza vaccine. We have developed an in vitro model system for producing a membrane-bound Cytokine-bearing Influenza Vaccine (CYT-IVAC). Numerous cytokines are involved in directing both innate and adaptive immunity and it is our goal to utilize the properties of individual cytokines and other immunomodulatory proteins to create a more immunogenic vaccine. Results We have evaluated the immunogenicity of inactivated cytokine-bearing influenza vaccines using a mouse model of lethal influenza virus challenge. CYT-IVACs were produced by stably transfecting MDCK cell lines with mouse-derived cytokines (GM-CSF, IL-2 and IL-4) fused to the membrane-anchoring domain of the viral hemagglutinin. Influenza virus replication in these cell lines resulted in the uptake of the bioactive membrane-bound cytokines during virus budding and release. In vivo efficacy studies revealed that a single low dose of IL-2 or IL-4-bearing CYT-IVAC is superior at providing protection against lethal influenza challenge in a mouse model and provides a more balanced Th1/Th2 humoral immune response, similar to live virus infections. Conclusion We have validated the protective efficacy of CYT-IVACs in a mammalian model of influenza virus infection. This technology has broad applications in current influenza virus vaccine development and may prove particularly useful in boosting immune responses in the elderly, where current vaccines are minimally effective. PMID:19393093

  13. Swine Influenza/Variant Influenza Viruses

    MedlinePlus

    ... Humans Key Facts about Human Infections with Variant Viruses Interim Guidance for Clinicians on Human Infections Background, Risk Assessment & Reporting Reported Infections with Variant Influenza Viruses in the United States since 2005 Prevention Treatment ...

  14. Immunosuppression During Influenza Virus Infection

    PubMed Central

    Kantzler, G. B.; Lauteria, S. F.; Cusumano, C. L.; Lee, J. D.; Ganguly, R.; Waldman, R. H.

    1974-01-01

    The effects of a live attenuated influenza vaccine and subsequent challenge with virulent influenza virus on the delayed hypersensitivity skin test, and the in vitro response of lymphocytes were evaluated. Volunteers were skin tested before and after administration of vaccine or placebo and challenge with PPD (a purified protein derivative of Mycobacterium tuberculosis), candida, mumps, and trichophytin, and their lymphocytes were tested for [3H]thymidine uptake in response to phytohemagglutin. Of eight volunteers who showed evidence of viral replication after administration of the attenuated vaccine, four had a significant diminution in their skin test response, whereas 8 of 13 volunteers infected with virulent influenza virus showed a diminution. Of the 21 volunteers who were infected with either attenuated or virulent influenza virus, 12 showed suppression of their phytohemagglutin response. None of the volunteers who were given placebo vaccine, or who showed no evidence for viral replication after immunization or challenge, had a suppression of their skin test or phytohemagglutin responses. Although most of the infected volunteers demonstrated suppression of their T-cell function, there was no evidence of a similar suppression of B-cell function. PMID:16558116

  15. A Bird's Eye View of Influenza A Virus Transmission: Challenges with Characterizing Both Sides of a Co-Evolutionary Dynamic.

    PubMed

    Hill, Nichola J; Runstadler, Jonathan A

    2016-08-01

    In nature, wild birds and influenza A viruses (IAV) are continually co-evolving, locked into a back-and-forth of resistance and conquest that has approached a stable equilibrium over time. This co-evolutionary relationship between bird host and IAV may appear stable at the organismal level, but is highly dynamic at the molecular level manifesting in a constant trade-off between transmissibility and virulence of the virus. Characterizing both sides of the host-virus dynamic has presented a challenge for ecologists and virologists alike, despite the potential for this approach to provide insights into which conditions destabilize the equilibrium state resulting in outbreaks or mortality of hosts in extreme cases. The use of different methods that are either host-centric or virus-centric has made it difficult to reconcile the disparate fields of host ecology and virology for investigating and ultimately predicting wild bird-mediated transmission of IAV. This review distills some of the key lessons learned from virological and ecological studies and explores the promises and pitfalls of both approaches. Ultimately, reconciling ecological and virological approaches hinges on integrating scales for measuring host-virus interactions. We argue that prospects for finding common scales for measuring wild bird-influenza dynamics are improving due to advances in genomic sequencing, host-tracking technology and remote sensing data, with the unit of time (months, year, or seasons) providing a starting point for crossover. PMID:27252222

  16. Newcastle Disease Virus-Vectored Vaccines Expressing the Hemagglutinin or Neuraminidase Protein of H5N1 Highly Pathogenic Avian Influenza Virus Protect against Virus Challenge in Monkeys▿

    PubMed Central

    DiNapoli, Joshua M.; Nayak, Baibaswata; Yang, Lijuan; Finneyfrock, Brad W.; Cook, Anthony; Andersen, Hanne; Torres-Velez, Fernando; Murphy, Brian R.; Samal, Siba K.; Collins, Peter L.; Bukreyev, Alexander

    2010-01-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) causes periodic outbreaks in humans, resulting in severe infections with a high (60%) incidence of mortality. The circulating strains have low human-to-human transmissibility; however, widespread concerns exist that enhanced transmission due to mutations could lead to a global pandemic. We previously engineered Newcastle disease virus (NDV), an avian paramyxovirus, as a vector to express the HPAIV hemagglutinin (HA) protein, and we showed that this vaccine (NDV/HA) induced a high level of HPAIV-specific mucosal and serum antibodies in primates when administered through the respiratory tract. Here we developed additional NDV-vectored vaccines expressing either HPAIV HA in which the polybasic cleavage site was replaced with that from a low-pathogenicity strain of influenza virus [HA(RV)], in order to address concerns of enhanced vector replication or genetic exchange, or HPAIV neuraminidase (NA). The three vaccine viruses [NDV/HA, NDV/HA(RV), and NDV/NA] were administered separately to groups of African green monkeys by the intranasal/intratracheal route. An additional group of animals received NDV/HA by aerosol administration. Each of the vaccine constructs was highly restricted for replication, with only low levels of virus shedding detected in respiratory secretions. All groups developed high levels of neutralizing antibodies against homologous and heterologous strains of HPAIV and were protected against challenge with 2 × 107 PFU of homologous HPAIV. Thus, needle-free, highly attenuated NDV-vectored vaccines expressing either HPAIV HA, HA(RV), or NA have been developed and demonstrated to be individually immunogenic and protective in a primate model of HPAIV infection. The finding that HA(RV) was protective indicates that it would be preferred for inclusion in a vaccine. The study also identified NA as an independent protective HPAIV antigen in primates. Furthermore, we demonstrated the feasibility of aerosol

  17. A plant-produced H1N1 trimeric hemagglutinin protects mice from a lethal influenza virus challenge

    PubMed Central

    Shoji, Yoko; Jones, R. Mark; Mett, Vadim; Chichester, Jessica A.; Musiychuk, Konstantin; Sun, Xiangjie; Tumpey, Terrence M.; Green, Brian J.; Shamloul, Moneim; Norikane, Joey; Bi, Hong; Hartman, Caitlin E.; Bottone, Cory; Stewart, Michelle; Streatfield, Stephen J.; Yusibov, Vidadi

    2013-01-01

    The increased worldwide awareness of seasonal and pandemic influenza, including pandemic H1N1 virus, has stimulated interest in the development of economic platforms for rapid, large-scale production of safe and effective subunit vaccines. In recent years, plants have demonstrated their utility as such a platform and have been used to produce vaccine antigens against various infectious diseases. Previously, we have produced in our transient plant expression system a recombinant monomeric hemagglutinin (HA) protein (HAC1) derived from A/California/04/09 (H1N1) strain of influenza virus and demonstrated its immunogenicity and safety in animal models and human volunteers. In the current study, to mimic the authentic HA structure presented on the virus surface and to improve stability and immunogenicity of the HA antigen, we generated trimeric HA by introducing a trimerization motif from a heterologous protein into the HA sequence. Here, we describe the engineering, production in Nicotiana benthamiana plants, and characterization of the highly purified recombinant trimeric HA protein (tHA-BC) from A/California/04/09 (H1N1) strain of influenza virus. The results demonstrate the induction of serum hemagglutination inhibition antibodies by tHA-BC and its protective efficacy in mice against a lethal viral challenge. In addition, the immunogenic and protective doses of tHA-BC were much lower compared with monomeric HAC1. Further investigation into the optimum vaccine dose and/or regimen as well as the stability of trimerized HA is necessary to determine whether trimeric HA is a more potent vaccine antigen than monomeric HA. PMID:23296194

  18. Virus-Vectored Influenza Virus Vaccines

    PubMed Central

    Tripp, Ralph A.; Tompkins, S. Mark

    2014-01-01

    Despite the availability of an inactivated vaccine that has been licensed for >50 years, the influenza virus continues to cause morbidity and mortality worldwide. Constant evolution of circulating influenza virus strains and the emergence of new strains diminishes the effectiveness of annual vaccines that rely on a match with circulating influenza strains. Thus, there is a continued need for new, efficacious vaccines conferring cross-clade protection to avoid the need for biannual reformulation of seasonal influenza vaccines. Recombinant virus-vectored vaccines are an appealing alternative to classical inactivated vaccines because virus vectors enable native expression of influenza antigens, even from virulent influenza viruses, while expressed in the context of the vector that can improve immunogenicity. In addition, a vectored vaccine often enables delivery of the vaccine to sites of inductive immunity such as the respiratory tract enabling protection from influenza virus infection. Moreover, the ability to readily manipulate virus vectors to produce novel influenza vaccines may provide the quickest path toward a universal vaccine protecting against all influenza viruses. This review will discuss experimental virus-vectored vaccines for use in humans, comparing them to licensed vaccines and the hurdles faced for licensure of these next-generation influenza virus vaccines. PMID:25105278

  19. Aerosol Delivery of a Candidate Universal Influenza Vaccine Reduces Viral Load in Pigs Challenged with Pandemic H1N1 Virus.

    PubMed

    Morgan, Sophie B; Hemmink, Johanneke D; Porter, Emily; Harley, Ross; Shelton, Holly; Aramouni, Mario; Everett, Helen E; Brookes, Sharon M; Bailey, Michael; Townsend, Alain M; Charleston, Bryan; Tchilian, Elma

    2016-06-15

    Influenza A viruses are a major health threat to livestock and humans, causing considerable mortality, morbidity, and economic loss. Current inactivated influenza vaccines are strain specific and new vaccines need to be produced at frequent intervals to combat newly arising influenza virus strains, so that a universal vaccine is highly desirable. We show that pandemic H1N1 influenza virus in which the hemagglutinin signal sequence has been suppressed (S-FLU), when administered to pigs by aerosol can induce CD4 and CD8 T cell immune responses in blood, bronchoalveolar lavage (BAL), and tracheobronchial lymph nodes. Neutralizing Ab was not produced. Detection of a BAL response correlated with a reduction in viral titer in nasal swabs and lungs, following challenge with H1N1 pandemic virus. Intratracheal immunization with a higher dose of a heterologous H5N1 S-FLU vaccine induced weaker BAL and stronger tracheobronchial lymph node responses and a lesser reduction in viral titer. We conclude that local cellular immune responses are important for protection against influenza A virus infection, that these can be most efficiently induced by aerosol immunization targeting the lower respiratory tract, and that S-FLU is a promising universal influenza vaccine candidate. PMID:27183611

  20. Aerosol Delivery of a Candidate Universal Influenza Vaccine Reduces Viral Load in Pigs Challenged with Pandemic H1N1 Virus

    PubMed Central

    Morgan, Sophie B.; Hemmink, Johanneke D.; Porter, Emily; Harley, Ross; Shelton, Holly; Aramouni, Mario; Everett, Helen E.; Brookes, Sharon M.; Bailey, Michael; Townsend, Alain M.; Charleston, Bryan

    2016-01-01

    Influenza A viruses are a major health threat to livestock and humans, causing considerable mortality, morbidity, and economic loss. Current inactivated influenza vaccines are strain specific and new vaccines need to be produced at frequent intervals to combat newly arising influenza virus strains, so that a universal vaccine is highly desirable. We show that pandemic H1N1 influenza virus in which the hemagglutinin signal sequence has been suppressed (S-FLU), when administered to pigs by aerosol can induce CD4 and CD8 T cell immune responses in blood, bronchoalveolar lavage (BAL), and tracheobronchial lymph nodes. Neutralizing Ab was not produced. Detection of a BAL response correlated with a reduction in viral titer in nasal swabs and lungs, following challenge with H1N1 pandemic virus. Intratracheal immunization with a higher dose of a heterologous H5N1 S-FLU vaccine induced weaker BAL and stronger tracheobronchial lymph node responses and a lesser reduction in viral titer. We conclude that local cellular immune responses are important for protection against influenza A virus infection, that these can be most efficiently induced by aerosol immunization targeting the lower respiratory tract, and that S-FLU is a promising universal influenza vaccine candidate. PMID:27183611

  1. Two doses of parenterally administered split influenza virus vaccine elicited high serum IgG concentrations which effectively limited viral shedding upon challenge in mice.

    PubMed

    Hovden, A-O; Cox, R J; Madhun, A; Haaheim, L R

    2005-10-01

    We have previously found that whole influenza virus vaccine induced a more rapid and stronger humoral response, particularly after the first dose of vaccine, than split virus vaccine in mice. In this study, we have evaluated the protective efficacy of whole and split influenza virus vaccines in mice using a nonlethal upper respiratory tract challenge model. We have also investigated the immunological correlates associated with no or very little viral shedding after viral challenge. Vaccination resulted in reduced viral shedding and shortened the duration of infection by at least 2 days. After one dose of vaccine, whole virus vaccine generally resulted in less viral shedding than split virus vaccine. In contrast, two doses of split virus vaccine, particularly the highest vaccine strengths of 15 and 30 microg HA, most effectively limited viral replication and these mice had high concentrations of prechallenge influenza-specific serum IgG. The vaccine formulation influenced the IgG2a/IgG1 ratio, and this IgG subclass profile was maintained upon challenge to some extent, although it did not influence the level of viral shedding. The concentration of postvaccination serum IgG showed an inverse relationship with the level of viral shedding after viral challenge. Therefore, serum IgG is an important factor in limiting viral replication in the upper respiratory tract upon challenge of an antigenically similar virus. PMID:16253121

  2. Pathobiology of avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus causes serious disease in a wide variety of birds and mammals. Its natural hosts are wild aquatic birds, in which most infections are unapparent. Avian Influenza (AI) viruses are classified into 16 hemagglutinin (H1-16) and nine neuraminidase (N1-9) subtypes. Each virus has on...

  3. Influenza Vaccines: Challenges and Solutions

    PubMed Central

    Houser, Katherine; Subbarao, Kanta

    2015-01-01

    Vaccination is the best method for the prevention and control of influenza. Vaccination can reduce illness and lessen severity of infection. This review focuses on how currently licensed influenza vaccines are generated in the U.S., why the biology of influenza poses vaccine challenges, and vaccine approaches on the horizon that address these challenges. PMID:25766291

  4. Intranasal vaccination with replication-defective adenovirus type 5 encoding influenza virus hemagglutinin elicits protective immunity to homologous challenge and partial protection to heterologous challenge in pigs.

    PubMed

    Braucher, Douglas R; Henningson, Jamie N; Loving, Crystal L; Vincent, Amy L; Kim, Eun; Steitz, Julia; Gambotto, Andrea A; Kehrli, Marcus E

    2012-11-01

    Influenza A virus (IAV) is widely circulating in the swine population and causes significant economic losses. To combat IAV infection, the swine industry utilizes adjuvanted whole inactivated virus (WIV) vaccines, using a prime-boost strategy. These vaccines can provide sterilizing immunity toward homologous virus but often have limited efficacy against a heterologous infection. There is a need for vaccine platforms that induce mucosal and cell-mediated immunity that is cross-reactive to heterologous viruses and can be produced in a short time frame. Nonreplicating adenovirus 5 vector (Ad5) vaccines are one option, as they can be produced rapidly and given intranasally to induce local immunity. Thus, we compared the immunogenicity and efficacy of a single intranasal dose of an Ad5-vectored hemagglutinin (Ad5-HA) vaccine to those of a traditional intramuscular administration of WIV vaccine. Ad5-HA vaccination induced a mucosal IgA response toward homologous IAV and primed an antigen-specific gamma interferon (IFN-γ) response against both challenge viruses. The Ad5-HA vaccine provided protective immunity to homologous challenge and partial protection against heterologous challenge, unlike the WIV vaccine. Nasal shedding was significantly reduced and virus was cleared from the lung by day 5 postinfection following heterologous challenge of Ad5-HA-vaccinated pigs. However, the WIV-vaccinated pigs displayed vaccine-associated enhanced respiratory disease (VAERD) following heterologous challenge, characterized by enhanced macroscopic lung lesions. This study demonstrates that a single intranasal vaccination with an Ad5-HA construct can provide complete protection from homologous challenge and partial protection from heterologous challenge, as opposed to VAERD, which can occur with adjuvanted WIV vaccines. PMID:22933397

  5. Kinetics of lung lesion development and pro-inflammatory cytokine response in pigs with vaccine-associated enhanced respiratory disease induced by challenge with pandemic (2009) A/H1N1 influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this report was to characterize the enhanced clinical disease and lung lesions observed in pigs vaccinated with inactivated H1N2 swine delta-cluster influenza A virus and challenged with pandemic 2009 A/H1N1 human influenza virus. Eighty-four, six-week-old, crossbred pigs were rand...

  6. Accelerating Influenza Research: Vaccines, Antivirals, Immunomodulators and Monoclonal Antibodies. The Manufacture of a New Wild-Type H3N2 Virus for the Human Viral Challenge Model

    PubMed Central

    Fullen, Daniel J.; Noulin, Nicolas; Catchpole, Andrew; Fathi, Hosnieh; Murray, Edward J.; Mann, Alex; Eze, Kingsley; Balaratnam, Ganesh; Borley, Daryl W.; Gilbert, Anthony; Lambkin-Williams, Rob

    2016-01-01

    Background Influenza and its associated diseases are a major cause of morbidity and mortality. The United States Advisory Committee on Immunization Practices recommends influenza vaccination for everyone over 6 months of age. The failure of the flu vaccine in 2014–2015 demonstrates the need for a model that allows the rapid development of novel antivirals, universal/intra-seasonal vaccines, immunomodulators, monoclonal antibodies and other novel treatments. To this end we manufactured a new H3N2 influenza virus in compliance with Good Manufacturing Practice for use in the Human Viral Challenge Model. Methods and Strain Selection We chose an H3N2 influenza subtype, rather than H1N1, given that this strain has the most substantial impact in terms of morbidity or mortality annually as described by the Centre for Disease Control. We first subjected the virus batch to rigorous adventitious agent testing, confirmed the virus to be wild-type by Sanger sequencing and determined the virus titres appropriate for human use via the established ferret model. We built on our previous experience with other H3N2 and H1N1 viruses to develop this unique model. Human Challenge and Conclusions We conducted an initial safety and characterisation study in healthy adult volunteers, utilising our unique clinical quarantine facility in London, UK. In this study we demonstrated this new influenza (H3N2) challenge virus to be both safe and pathogenic with an appropriate level of disease in volunteers. Furthermore, by inoculating volunteers with a range of different inoculum titres, we established the minimum infectious titre required to achieve reproducible disease whilst ensuring a sensitive model that can be translated to design of subsequent field based studies. Trial Registration ClinicalTrials.gov NCT02525055 PMID:26761707

  7. A recombinant influenza virus vaccine expressing the F protein of respiratory syncytial virus

    PubMed Central

    Fonseca, Wendy; Ozawa, Makoto; Hatta, Masato; Orozco, Esther; Martínez, Máximo B; Kawaoka, Yoshihiro

    2014-01-01

    Infections with influenza and respiratory syncytial virus (RSV) rank high among the most common human respiratory diseases worldwide. Previously, we developed a replication-incompetent influenza virus by replacing the coding sequence of the PB2 gene, which encodes one of the viral RNA polymerase subunits, with that of a reporter gene. Here, we generated a PB2-knockout recombinant influenza virus expressing the F protein of RSV (PB2-RSVF virus) and tested its potential as a bivalent vaccine. In mice intranasally immunized with the PB2-RSVF virus, we detected high levels of antibodies against influenza virus, but not RSV. PB2-RSVF virus-immunized mice were protected from a lethal challenge with influenza virus but experienced severe body weight loss when challenged with RSV, indicating that PB2-RSVF vaccination enhanced RSV-associated disease. These results highlight one of the difficulties of developing an effective bivalent vaccine against influenza virus and RSV infections. PMID:24292020

  8. Protective efficacy of recombinant and inactivated H5 avian influenza vaccines against challenge from the 2014 intercontinental H5 highly pathogenic avian influenza viruses (H5N8 and H5N2)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protective immunity against highly pathogenic avian influenza (HPAI) largely depends on the development of an antibody response against a specific subtype of challenge virus. Historically, the use of antigenically closely matched isolates has proven efficacious when used as inactivated vaccines. M...

  9. Structural basis of influenza virus neutralization

    PubMed Central

    Han, Thomas; Marasco, Wayne A.

    2010-01-01

    Although seasonal influenza vaccines play a valuable role in reducing the spread of the virus at the population level, ongoing viral evolution to evade immune responses remains problematic. No current vaccines are likely to elicit enduring protection in the face of emerging and re-emerging influenza viruses that rapidly undergoing antigenic drift. Eliciting broadly cross-neutralizing antibody responses against influenza virus is a crucial goal for seasonal and pandemic influenza vaccine preparation. Recent three-dimensional structure information obtained from crystallization of influenza antigens in complex with neutralizing antibodies (nAbs) have provided a framework for interpreting antibody-based viral neutralization that should aid in the design of vaccine immunogens. Here, we will review current knowledge of the structure-based mechanisms contributing to the neutralization and neutralization escape of influenza viruses. We will also explore the potential for this structure-based approach to overcome the challenge of obtaining the highly desired “universal” influenza vaccine. PMID:21251008

  10. Novel vaccines against influenza viruses

    PubMed Central

    Kang, Sang-Moo; Song, Jae-Min; Compans, Richard W.

    2011-01-01

    Killed and live attenuated influenza virus vaccines are effective in preventing and curbing the spread of influenza epidemics when the strains present in the vaccines are closely matched with the predicted epidemic strains. These vaccines are primarily targeted to induce immunity to the variable major target antigen, hemagglutinin (HA) of influenza virus. However, current vaccines are not effective in preventing the emergence of new pandemic or highly virulent viruses. New approaches are being investigated to develop universal influenza virus vaccines as well as to apply more effective vaccine delivery methods. Conserved vaccine targets including the influenza M2 ion channel protein and HA stalk domains are being developed using recombinant technologies to improve the level of cross protection. In addition, recent studies provide evidence that vaccine supplements can provide avenues to further improve current vaccination. PMID:21968298

  11. Emergence of influenza A viruses.

    PubMed Central

    Webby, R J; Webster, R G

    2001-01-01

    Pandemic influenza in humans is a zoonotic disease caused by the transfer of influenza A viruses or virus gene segments from animal reservoirs. Influenza A viruses have been isolated from avian and mammalian hosts, although the primary reservoirs are the aquatic bird populations of the world. In the aquatic birds, influenza is asymptomatic, and the viruses are in evolutionary stasis. The aquatic bird viruses do not replicate well in humans, and these viruses need to reassort or adapt in an intermediate host before they emerge in human populations. Pigs can serve as a host for avian and human viruses and are logical candidates for the role of intermediate host. The transmission of avian H5N1 and H9N2 viruses directly to humans during the late 1990s showed that land-based poultry also can serve between aquatic birds and humans as intermediate hosts of influenza viruses. That these transmission events took place in Hong Kong and China adds further support to the hypothesis that Asia is an epicentre for influenza and stresses the importance of surveillance of pigs and live-bird markets in this area. PMID:11779380

  12. Variant (Swine Origin) Influenza Viruses in Humans

    MedlinePlus

    ... What's this? Submit Button Past Newsletters Variant Influenza Viruses: Background and CDC Risk Assessment and Reporting Language: ... Background CDC Assessment Reporting Background On Variant Influenza Viruses Swine flu viruses do not normally infect humans. ...

  13. New aspects of influenza viruses.

    PubMed Central

    Shaw, M W; Arden, N H; Maassab, H F

    1992-01-01

    Influenza virus infections continue to cause substantial morbidity and mortality with a worldwide social and economic impact. The past five years have seen dramatic advances in our understanding of viral replication, evolution, and antigenic variation. Genetic analyses have clarified relationships between human and animal influenza virus strains, demonstrating the potential for the appearance of new pandemic reassortants as hemagglutinin and neuraminidase genes are exchanged in an intermediate host. Clinical trials of candidate live attenuated influenza virus vaccines have shown the cold-adapted reassortants to be a promising alternative to the currently available inactivated virus preparations. Modern molecular techniques have allowed serious consideration of new approaches to the development of antiviral agents and vaccines as the functions of the viral genes and proteins are further elucidated. The development of techniques whereby the genes of influenza viruses can be specifically altered to investigate those functions will undoubtedly accelerate the pace at which our knowledge expands. PMID:1310439

  14. Lemna (duckweed) expressed hemagglutinin from avian influenza H5N1 protects chickens against H5N1 high pathogenicity avian influenza virus challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the last two decades, transgenic plants have been explored as safe and cost effective alternative expression platforms for producing recombinant proteins. In this study, a synthetic hemagglutinin (HA) gene from the high pathogenicity avian influenza (HPAI) virus A/chicken/Indonesia/7/2003 (H5N1)...

  15. Protection against avian influenza H9N2 virus challenge by immunization with hemagglutinin- or neuraminidase-expressing DNA in BALB/c mice

    SciTech Connect

    Qiu Meizhen; Fang Fang; Chen Yan; Wang Hualin; Chen Quanjiao; Chang Haiyan; Wang Fuyan; Wang Hanzhong; Zhang Ran; Chen Ze . E-mail: chenze2005@263.net

    2006-05-19

    Avian influenza viruses of H9N2 subtype are widely spread in avian species. The viruses have recently been transmitted to mammalian species, including humans, accelerating the efforts to devise protective strategies against them. In this study, an avian influenza H9N2 virus strain (A/Chicken/Jiangsu/7/2002), isolated in Jiangsu Province, China, was used to infect BALB/c mice for adaptation. After five lung-to-lung passages, the virus was stably proliferated in a large quantity in the murine lung and caused the deaths of mice. In addition, we explored the protection induced by H9N2 virus hemagglutinin (HA)- and neuraminidase (NA)-expressing DNAs in BALB/c mice. Female BALB/c mice aged 6-8 weeks were immunized once or twice at a 3-week interval with HA-DNA and NA-DNA by electroporation, respectively, each at a dose of 3, 10 or 30 {mu}g. The mice were challenged with a lethal dose (40x LD{sub 5}) of influenza H9N2 virus four weeks after immunization once or one week after immunization twice. The protections of DNA vaccines were evaluated by the serum antibody titers, residual lung virus titers, and survival rates of the mice. The result showed that immunization once with not less than 10 {mu}g or twice with 3 {mu}g HA-DNA or NA-DNA provided effective protection against homologous avian influenza H9N2 virus.

  16. Avian influenza virus RNA extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficient extraction and purification of viral RNA is critical for down-stream molecular applications whether it is the sensitive and specific detection of virus in clinical samples, virus gene cloning and expression, or quantification of avian influenza (AI) virus by molecular methods from expe...

  17. Challenges and Strategies of Laboratory Diagnosis for Newly Emerging Influenza Viruses in Taiwan: A Decade after SARS

    PubMed Central

    Lin, Jih-Hui; Wu, Ho-Sheng

    2015-01-01

    Since the first case of severe acute respiratory syndrome (SARS) in Taiwan was identified in March 2003, viral respiratory infections, in particular the influenza virus, have become a national public health concern. Taiwan would face a serious threat of public health problems if another SARS epidemic overlapped with a flu outbreak. After SARS, the Taiwan Centers for Disease Control accelerated and strengthened domestic research on influenza and expanded the exchange of information with international counterparts. The capacity of influenza A to cross species barriers presents a potential threat to human health. Given the mutations of avian flu viruses such as H7N9, H6N1, and H10N8, all countries, including Taiwan, must equip themselves to face a possible epidemic or pandemic. Such preparedness requires global collaboration. PMID:26290876

  18. Newcastle Disease Virus-Based Live Attenuated Vaccine Completely Protects Chickens and Mice from Lethal Challenge of Homologous and Heterologous H5N1 Avian Influenza Viruses▿

    PubMed Central

    Ge, Jinying; Deng, Guohua; Wen, Zhiyuan; Tian, Guobing; Wang, Yong; Shi, Jianzhong; Wang, Xijun; Li, Yanbing; Hu, Sen; Jiang, Yongping; Yang, Chinglai; Yu, Kangzhen; Bu, Zhigao; Chen, Hualan

    2007-01-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) has continued to spread and poses a significant threat to both animal and human health. Current influenza vaccine strategies have limitations that prevent their effective use for widespread inoculation of animals in the field. Vaccine strains of Newcastle disease virus (NDV), however, have been used successfully to easily vaccinate large numbers of animals. In this study, we used reverse genetics to construct a NDV that expressed an H5 subtype avian influenza virus (AIV) hemagglutinin (HA). Both a wild-type and a mutated HA open reading frame (ORF) from the HPAIV wild bird isolate, A/Bar-headed goose/Qinghai/3/2005 (H5N1), were inserted into the intergenic region between the P and M genes of the LaSota NDV vaccine strain. The recombinant viruses stably expressing the wild-type and mutant HA genes were found to be innocuous after intracerebral inoculation of 1-day-old chickens. A single dose of the recombinant viruses in chickens induced both NDV- and AIV H5-specific antibodies and completely protected chickens from challenge with a lethal dose of both velogenic NDV and homologous and heterologous H5N1 HPAIV. In addition, BALB/c mice immunized with the recombinant NDV-based vaccine produced H5 AIV-specific antibodies and were completely protected from homologous and heterologous lethal virus challenge. Our results indicate that recombinant NDV is suitable as a bivalent live attenuated vaccine against both NDV and AIV infection in poultry. The recombinant NDV vaccine may also have potential use in high-risk human individuals to control the pandemic spread of lethal avian influenza. PMID:17050610

  19. Characterization of 10 adjuvants for inactivated avian influenza virus (AIV) vaccines against challenge with highly pathogenic AIV in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inactivated vaccines comprise 95% of all vaccine used for avian influenza virus (AIV) by dose. Optimizing the adjuvant is one way to improve vaccine efficacy. Inactivated vaccines were produced with beta-propiolactone inactivated A/chicken/BC/314514-1/2004 H7N3 low pathogenicity AIV and standardiz...

  20. Vaccination and acute phase mediator production in chickens challenged with low pathogenic avian influenza virus; novel markers for vaccine efficacy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods to determine vaccine efficacy of low pathogenic avian influenza (LPAI) isolates are limited in poultry because experimental infections with LPAI virus in specific pathogen free chickens rarely causes clinical disease. The most commonly used method to compare LPAI vaccine efficacy is to quant...

  1. Transmission of Influenza A Viruses

    PubMed Central

    Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to ‘novel’ viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages. PMID:25812763

  2. Transmission of influenza A viruses.

    PubMed

    Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-05-01

    Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to 'novel' viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages. PMID:25812763

  3. Demonstration of d-Octaarginine-Linked Polymers as Promising Adjuvants for Mucosal Vaccination through Influenza Virus Challenge.

    PubMed

    Miyata, Kohei; Mohri, Kohta; Egawa, Tomomi; Endo, Rikito; Morimoto, Naoki; Ochiai, Kyohei; Hiwatari, Ken-Ichiro; Tsubaki, Kazufumi; Tobita, Etsuo; Uto, Tomofumi; Baba, Masanori; Sakuma, Shinji

    2016-08-17

    Mucosal vaccination is one of the most effective ways to reduce the risk of pandemics as a result of incorrect prediction of epidemic strains of influenza viruses or virus mutation. However, adjuvants and antigen carriers with potent immunostimulatory activities are a prerequisite for significant induction of mucosal immunity because most antigens are poorly immunogenic when solely applied to the mucosa. Our previous studies demonstrated that poly(N-vinylacetamide-co-acrylic acid) bearing d-octaarginine induced the secretion of antigen-specific immunoglobulin A (IgA) on the mucosa when nasally administered with virus antigens and that intranasal IgA reacts to viral strains other than the one used for immunization. Therefore, the present study evaluated capabilities of secreted IgA for protection against virus infection. When mice were inoculated with a mixture of inactivated H1N1 A/Puerto Rico/8/34 influenza viruses and d-octaarginine-linked polymers, antigen-specific secreted IgA was induced on the nasal mucosa. Immunized mice were completely protected from virus infection of the inoculated strain. To the contrary, mice nasally inoculated with inactivated viruses alone were infected with the homologous viruses presumably because of insignificant induction of secreted IgA. Results demonstrated that our polymer would be a promising adjuvant for mucosal vaccination. PMID:27463562

  4. Vaccine efficacy and immune response to swine influenza virus challenge in pigs infected with porcine reproductive and respiratory syndrome virus at the time of SIV-vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to assess the effect of concurrent infection with porcine reproductive and respiratory syndrome virus (PRRSV) on the efficacy of an inactivated swine influenza virus (SIV) vaccine. Eight groups of pigs were used in the study. One group was infected with a virulent PR...

  5. Household Transmission of Influenza Virus.

    PubMed

    Tsang, Tim K; Lau, Lincoln L H; Cauchemez, Simon; Cowling, Benjamin J

    2016-02-01

    Human influenza viruses cause regular epidemics and occasional pandemics with a substantial public health burden. Household transmission studies have provided valuable information on the dynamics of influenza transmission. We reviewed published studies and found that once one household member is infected with influenza, the risk of infection in a household contact can be up to 38%, and the delay between onset in index and secondary cases is around 3 days. Younger age was associated with higher susceptibility. In the future, household transmission studies will provide information on transmission dynamics, including the correlation of virus shedding and symptoms with transmission, and the correlation of new measures of immunity with protection against infection. PMID:26612500

  6. Intranasal vaccination with a plant-derived H5 HA vaccine protects mice and ferrets against highly pathogenic avian influenza virus challenge.

    PubMed

    Major, Diane; Chichester, Jessica A; Pathirana, Rishi D; Guilfoyle, Kate; Shoji, Yoko; Guzman, Carlos A; Yusibov, Vidadi; Cox, Rebecca J

    2015-01-01

    Highly pathogenic avian influenza H5N1 infection remains a public health threat and vaccination is the best measure of limiting the impact of a potential pandemic. Mucosal vaccines have the advantage of eliciting immune responses at the site of viral entry, thereby preventing infection as well as further viral transmission. In this study, we assessed the protective efficacy of hemagglutinin (HA) from the A/Indonesia/05/05 (H5N1) strain of influenza virus that was produced by transient expression in plants. The plant-derived vaccine, in combination with the mucosal adjuvant (3',5')-cyclic dimeric guanylic acid (c-di-GMP) was used for intranasal immunization of mice and ferrets, before challenge with a lethal dose of the A/Indonesia/05/05 (H5N1) virus. Mice vaccinated with 15 μg or 5 μg of adjuvanted HA survived the viral challenge, while all control mice died within 10 d of challenge. Vaccinated animals elicited serum hemagglutination inhibition, IgG and IgA antibody titers. In the ferret challenge study, all animals vaccinated with the adjuvanted plant vaccine survived the lethal viral challenge, while 50% of the control animals died. In both the mouse and ferret models, the vaccinated animals were better protected from weight loss and body temperature changes associated with H5N1 infection compared with the non-vaccinated controls. Furthermore, the systemic spread of the virus was lower in the vaccinated animals compared with the controls. Results presented here suggest that the plant-produced HA-based influenza vaccine adjuvanted with c-di-GMP is a promising vaccine/adjuvant combination for the development of new mucosal influenza vaccines. PMID:25714901

  7. Live attenuated influenza A virus vaccine protects against A(H1N1)pdm09 heterologous challenge without vaccine associated enhanced respiratory disease.

    PubMed

    Gauger, Phillip C; Loving, Crystal L; Khurana, Surender; Lorusso, Alessio; Perez, Daniel R; Kehrli, Marcus E; Roth, James A; Golding, Hana; Vincent, Amy L

    2014-12-01

    Live-attenuated influenza virus (LAIV) vaccines may provide cross-protection against contemporary influenza A virus (IAV) in swine. Conversely, whole inactivated virus (WIV) vaccines have the potential risk of vaccine-associated enhanced respiratory disease (VAERD) when challenged with IAV of substantial antigenic drift. A temperature sensitive, intranasal H1N2 LAIV was compared to wild type exposure (WT) and an intramuscular WIV vaccine in a model shown to induce VAERD. WIV vaccinated swine challenged with pandemic A/H1N1 (H1N1pdm09) were not protected from infection and demonstrated severe respiratory disease consistent with VAERD. Lung lesions were mild and challenge virus was not detected in the respiratory tract of LAIV vaccinates. High levels of post-vaccination IgG serum antibodies targeting the H1N1pdm09 HA2 stalk domain were exclusively detected in the WIV group and associated with increased H1N1pdm09 virus infectivity in MDCK cells. In contrast, infection-enhancing antibodies were not detected in the serum of LAIV vaccinates and VAERD was not observed. PMID:25461535

  8. An overview of the epidemic of highly pathogenic H5N1 avian influenza virus in Egypt: epidemiology and control challenges.

    PubMed

    Abdelwhab, E M; Hafez, H M

    2011-05-01

    Emergence of the highly pathogenic avian influenza (HPAI) H5N1 virus in Egypt in mid-February 2006 caused significant losses for the poultry industry and constituted a potential threat to public health. Since late 2007, there has been increasing evidence that stable lineages of H5N1 viruses are being established in chickens and humans in Egypt. The virus has been detected in wild, feral and zoo birds and recently was found in donkeys and pigs. Most of the outbreaks in poultry and humans occurred in the highly populated Nile delta. The temporal pattern of the virus has changed since 2009 with outbreaks now occurring in the warmer months of the year. Challenges to control of endemic disease in Egypt are discussed. For the foreseeable future, unless a global collaboration exists, HPAI H5N1 virus in Egypt will continue to compromise the poultry industry, endanger public health and pose a serious pandemic threat. PMID:21281550

  9. Nasal commensal Staphylococcus epidermidis counteracts influenza virus

    PubMed Central

    Chen, Hui-Wen; Liu, Pei-Feng; Liu, Yu-Tsueng; Kuo, Sherwin; Zhang, Xing-Quan; Schooley, Robert T.; Rohde, Holger; Gallo, Richard L.; Huang, Chun-Ming

    2016-01-01

    Several microbes, including Staphylococcus epidermidis (S. epidermidis), a Gram-positive bacterium, live inside the human nasal cavity as commensals. The role of these nasal commensals in host innate immunity is largely unknown, although bacterial interference in the nasal microbiome may promote ecological competition between commensal bacteria and pathogenic species. We demonstrate here that S. epidermidis culture supernatants significantly suppressed the infectivity of various influenza viruses. Using high-performance liquid chromatography together with mass spectrometry, we identified a giant extracellular matrix-binding protein (Embp) as the major component involved in the anti-influenza effect of S. epidermidis. This anti-influenza activity was abrogated when Embp was mutated, confirming that Embp is essential for S. epidermidis activity against viral infection. We also showed that both S. epidermidis bacterial particles and Embp can directly bind to influenza virus. Furthermore, the injection of a recombinant Embp fragment containing a fibronectin-binding domain into embryonated eggs increased the survival rate of virus-infected chicken embryos. For an in vivo challenge study, prior Embp intranasal inoculation in chickens suppressed the viral titres and induced the expression of antiviral cytokines in the nasal tissues. These results suggest that S. epidermidis in the nasal cavity may serve as a defence mechanism against influenza virus infection. PMID:27306590

  10. Influenza Virus Infection of Marine Mammals.

    PubMed

    Fereidouni, Sasan; Munoz, Olga; Von Dobschuetz, Sophie; De Nardi, Marco

    2016-03-01

    Interspecies transmission may play a key role in the evolution and ecology of influenza A viruses. The importance of marine mammals as hosts or carriers of potential zoonotic pathogens such as highly pathogenic H5 and H7 influenza viruses is not well understood. The fact that influenza viruses are some of the few zoonotic pathogens known to have caused infection in marine mammals, evidence for direct transmission of influenza A virus H7N7 subtype from seals to man, transmission of pandemic H1N1 influenza viruses to seals and also limited evidence for long-term persistence of influenza B viruses in seal populations without significant genetic change, makes monitoring of influenza viruses in marine mammal populations worth being performed. In addition, such monitoring studies could be a great tool to better understand the ecology of influenza viruses in nature. PMID:25231137

  11. Avian Influenza A Virus Infections in Humans

    MedlinePlus

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Submit What's this? Submit Button Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Españ ...

  12. Immunization with Plant-Expressed Hemagglutinin Protects Chickens from Lethal Highly Pathogenic Avian Influenza Virus H5N1 Challenge Infection▿

    PubMed Central

    Kalthoff, Donata; Giritch, Anatoli; Geisler, Katharina; Bettmann, Ulrike; Klimyuk, Victor; Hehnen, Hans-Robert; Gleba, Yuri; Beer, Martin

    2010-01-01

    Highly pathogenic avian influenza (HPAI) is a striking disease in susceptible poultry, which leads to severe economic losses. Inactivated vaccines are the most widely used vaccines in avian influenza virus (AIV) vaccination programs. However, these vaccines interfere with the serological detection of wild-type AIV infections in immunized populations. The use of vaccines that allow differentiation between infected and vaccinated animals (DIVA strategy) would stop current stamping-out policies. Therefore, novel vaccination strategies are needed to allow improved protection of animals and humans against HPAI virus (HPAIV) infection. The presented study analyzed for the first time the immunogenic capacity of plant-expressed full-length hemagglutinin (rHA0) of HPAIV H5N1 in several vaccine formulations within the highly relevant host species chicken. We were able to express plant-expressed rHA0 at high levels and could show that, when administered with potent adjuvants, it is highly immunogenic and can fully protect chicken against lethal challenge infection. Real-time reverse transcription (RT)-PCR and serological tests demonstrated only marginally increased virus replication in animals vaccinated with plant-derived rHA0 compared to animals immunized with an inactivated reference vaccine. In addition, the use of plant-expressed rHA0 also allowed an easy serological differentiation of vaccinated from AIV-infected animals based on antibodies against the influenza virus NP protein. PMID:20810729

  13. Swine Influenza Virus: Emerging Understandings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: In March-April 2009, a novel pandemic H1N1 emerged in the human population in North America [1]. The gene constellation of the emerging virus was demonstrated to be a combination of genes from swine influenza A viruses (SIV) of North American and Eurasian lineages that had never before...

  14. Experimental challenge and pathology of highly pathogenic avian influenza virus H5N1 in dunlin (Calidris alpina), an intercontinental migrant shorebird species

    PubMed Central

    Hall, Jeffrey S.; Franson, J. Christian; Gill, Robert E.; Meteyer, Carol U.; TeSlaa, Joshua L.; Nashold, Sean; Dusek, Robert J.; Ip, Hon S.

    2011-01-01

    Please cite this paper as: Hall et al. (2011). Experimental challenge and pathology of highly pathogenic avian influenza virus H5N1 in dunlin (Calidris alpina), an intercontinental migrant shorebird species. Influenza and Other Respiratory Viruses 5(5), 365–372. Background  Shorebirds (Charadriiformes) are considered one of the primary reservoirs of avian influenza. Because these species are highly migratory, there is concern that infected shorebirds may be a mechanism by which highly pathogenic avian influenza virus (HPAIV) H5N1 could be introduced into North America from Asia. Large numbers of dunlin (Calidris alpina) migrate from wintering areas in central and eastern Asia, where HPAIV H5N1 is endemic, across the Bering Sea to breeding areas in Alaska. Low pathogenic avian influenza virus has been previously detected in dunlin, and thus, dunlin represent a potential risk to transport HPAIV to North America. To date no experimental challenge studies have been performed in shorebirds. Methods  Wild dunlin were inoculated intranasally and intrachoanally various doses of HPAIV H5N1. The birds were monitored daily for virus excretion, disease signs, morbidity, and mortality. Results  The infectious dose of HPAIV H5N1 in dunlin was determined to be 101.7 EID50/100 μl and that the lethal dose was 101.83 EID50/100 μl. Clinical signs were consistent with neurotropic disease, and histochemical analyses revealed that infection was systemic with viral antigen and RNA most consistently found in brain tissues. Infected birds excreted relatively large amounts of virus orally (104 EID50) and smaller amounts cloacally. Conclusions  Dunlin are highly susceptible to infection with HPAIV H5N1. They become infected after exposure to relatively small doses of the virus and if they become infected, they are most likely to suffer mortality within 3–5 days. These results have important implications regarding the risks of transport and transmission of HPAIV H5N1 to North

  15. A novel monoclonal antibody effective against lethal challenge with swine-lineage and 2009 pandemic H1N1 influenza viruses in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The HA protein of the 2009 pandemic H1N1viruses (14 H1N1pdm) is antigenically closely related to the HA of classical North American swine H1N1 influenza viruses (cH1N1). Since 1998, through reassortment and incorporation of HA genes from human H3N2 and H1N1 influenza viruses, swine influenza strains...

  16. Neuraminidase inhibitors for influenza B virus infection: efficacy and resistance

    PubMed Central

    Burnham, Andrew J.; Baranovich, Tatiana; Govorkova, Elena A.

    2013-01-01

    Many aspects of the biology and epidemiology of influenza B viruses are far less studied than for influenza A viruses, and one of these aspects is effectiveness and resistance to the clinically available antiviral drugs, the neuraminidase (NA) inhibitors (NAIs). Acute respiratory infections are one of the leading causes of death in children and adults, and influenza is among the few respiratory infections that can be prevented and treated by vaccination and antiviral treatment. Recent data has suggested that influenza B virus infections are of specific concern to pediatric patients because of the increased risk of severe disease. Treatment of influenza B is a challenging task for the following reasons: NAIs (e.g., oseltamivir and zanamivir) are the only FDA-approved class of antivirals available for treatment;the data suggest that oseltamivir is less effective than zanamivir in pediatric patients;zanamivir is not prescribed to patients younger than 7;influenza B viruses are less susceptible than influenza A viruses to NAIs in vitro;although the level of resistance to NAIs is low, the number of different molecular markers of resistance is higher than for influenza A viruses, and they are not well defined;the relationship between levels of NAI phenotypic resistance and known molecular markers, frequency of emergence, transmissibility, and fitness of NAI-resistant variants are not well established. This review presents current knowledge of the effectiveness of NAIs for influenza B virus and antiviral resistance in clinical, surveillance, and experimental studies. PMID:24013000

  17. Influenza virus-like particles produced by transient expression in Nicotiana benthamiana induce a protective immune response against a lethal viral challenge in mice.

    PubMed

    D'Aoust, Marc-André; Lavoie, Pierre-Olivier; Couture, Manon M-J; Trépanier, Sonia; Guay, Jean-Martin; Dargis, Michèle; Mongrand, Sébastien; Landry, Nathalie; Ward, Brian J; Vézina, Louis-P

    2008-12-01

    A strain-specific vaccine represents the best possible response to the threat of an influenza pandemic. Rapid delivery of such a vaccine to the world's population before the peak of the first infection wave seems to be an unattainable goal with the current influenza vaccine manufacturing capacity. Plant-based transient expression is one of the few production systems that can meet the anticipated surge requirement. To assess the capability of plant agroinfiltration to produce an influenza vaccine, we expressed haemagglutinin (HA) from strains A/Indonesia/5/05 (H5N1) and A/New Caledonia/20/99 (H1N1) by agroinfiltration of Nicotiana benthamiana plants. Size distribution analysis of protein content in infiltrated leaves revealed that HA was predominantly assembled into high-molecular-weight structures. H5-containing structures were purified and examination by transmission electron microscopy confirmed virus-like particle (VLP) assembly. High-performance thin layer chromatography analysis of VLP lipid composition highlighted polar and neutral lipid contents comparable with those of purified plasma membranes from tobacco plants. Electron microscopy of VLP-producing cells in N. benthamiana leaves confirmed that VLPs accumulated in apoplastic indentations of the plasma membrane. Finally, immunization of mice with two doses of as little as 0.1 microg of purified influenza H5-VLPs triggered a strong immune response against the homologous virus, whereas two doses of 0.5 microg of H5-VLPs conferred complete protection against a lethal challenge with the heterologous A/Vietnam/1194/04 (H5N1) strain. These results show, for the first time, that plants are capable of producing enveloped influenza VLPs budding from the plasma membrane; such VLPs represent very promising candidates for vaccination against influenza pandemic strains. PMID:19076615

  18. Vaccine protection against lethal homologous and heterologous challenge using recombinant AAV vectors expressing codon-optimized genes from pandemic swine origin influenza virus (SOIV).

    PubMed

    Sipo, Isaac; Knauf, Mathias; Fechner, Henry; Poller, Wolfgang; Planz, Oliver; Kurth, Reinhard; Norley, Stephen

    2011-02-11

    The recent H1N1 influenza pandemic and the inevitable delay between identification of the virus and production of the specific vaccine have highlighted the urgent need for new generation influenza vaccines that can preemptively induce broad immunity to different strains of the virus. In this study we have produced AAV-based vectors expressing the A/Mexico/4603/2009 (H1N1) hemagglutinin (HA), nucleocapsid (NP) and the matrix protein M1 and have evaluated their ability to induce specific immune response and protect mice against homologous and heterologous challenge. Each of the vaccine vectors elicited potent cellular and humoral immune responses in mice. Although immunization with AAV-M1 did not improve survival after challenge with the homologous strain, immunization with the AAV-H1 and AAV-NP vectors resulted in survival of all mice, as did inoculation with a combination of all three vectors. Furthermore, trivalent vaccination also conferred partial protection against challenge with the highly heterologous and virulent A/PR/8/34 strain of H1N1 influenza. PMID:21195079

  19. A baculovirus dual expression system-based vaccine confers complete protection against lethal challenge with H9N2 avian influenza virus in mice

    PubMed Central

    2011-01-01

    Background Avian influenza viruses of H9N2 subtype have become highly prevalent in avian species. Although these viruses generally cause only mild to moderate disease, they can infect a wide variety of species, including chickens, quail, turkeys, ducks, geese, pheasant, partridge, and pigeon, even transmitted to mammalian species, including humans, accelerating the efforts to devise protective strategies against them. Results The results showed that stronger immune responses were induced in a mouse model immunized with BV-Dual-HA than in those vaccinated with a DNA vaccine encoding the same antigen. Moreover, complete protection against lethal challenge with H9N2 virus was observed in mice. Conclusion BV-Dual-HA could be utilized as a vaccine candidate against H9N2 virus infection. PMID:21639929

  20. Avian influenza virus in pregnancy.

    PubMed

    Liu, Shelan; Sha, Jianping; Yu, Zhao; Hu, Yan; Chan, Ta-Chien; Wang, Xiaoxiao; Pan, Hao; Cheng, Wei; Mao, Shenghua; Zhang, Run Ju; Chen, Enfu

    2016-07-01

    The unprecedented epizootic of avian influenza viruses, such as H5N1, H5N6, H7N1 and H10N8, has continued to cause disease in humans in recent years. In 2013, another novel influenza A (H7N9) virus emerged in China, and 30% of those patients died. Pregnant women are particularly susceptible to avian influenza and are more likely to develop severe complications and to die, especially when infection occurs in the middle and late trimesters. Viremia is believed to occur infrequently, and thus vertical transmission induced by avian influenza appears to be rare. However, avian influenza increases the risk of adverse pregnancy outcomes, including spontaneous abortion, preterm birth and fatal distress. This review summarises 39 cases of pregnant women and their fetuses from different countries dating back to 1997, including 11, 15 and 13 infections with H7N9, H5N1 and the 2009 pandemic influenza (H1N1), respectively. We analysed the epidemic features, following the geographical, population and pregnancy trimester distributions; underlying diseases; exposure history; medical timelines; human-to-human transmission; pathogenicity and vertical transmission; antivirus treatments; maternal severity and mortality and pregnancy outcome. The common experiences reported in different countries and areas suggest that early identification and treatment are imperative. In the future, vigilant virologic and epidemiologic surveillance systems should be developed to monitor avian influenza viruses during pregnancy. Furthermore, extensive study on the immune mechanisms should be conducted, as this will guide safe, rational immunomodulatory treatment among this high-risk population. Most importantly, we should develop a universal avian influenza virus vaccine to prevent outbreaks of the different subtypes. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27187752

  1. Mucosal immunity induced by adenovirus-based H5N1 HPAI vaccine confers protection against a lethal H5N2 avian influenza virus challenge.

    PubMed

    Park, Ki Seok; Lee, Jiyeung; Ahn, So Shin; Byun, Young-Ho; Seong, Baik Lin; Baek, Yun Hee; Song, Min-Suk; Choi, Young Ki; Na, Yun Jeong; Hwang, Inhwan; Sung, Young Chul; Lee, Chang Geun

    2009-12-20

    Development of effective vaccines against highly pathogenic avian influenza (HPAI) H5N1 viruses is a global public health priority. Considering the difficulty in predicting HPAI H5N1 pandemic strains, one strategy used in their design includes the development of formulations with the capacity of eliciting broad cross-protective immunity against multiple viral antigens. To this end we constructed a replication-defective recombinant adenovirus-based avian influenza virus vaccine (rAdv-AI) expressing the codon-optimized M2eX-HA-hCD40L and the M1-M2 fusion genes from HPAI H5N1 human isolate. Although there were no significant differences in the systemic immune responses observed between the intramuscular prime-intramuscular boost regimen (IM/IM) and the intranasal prime-intramuscular boost regimen (IN/IM), IN/IM induced more potent CD8(+) T cell and antibody responses at mucosal sites than the IM/IM vaccination, resulting in more effective protection against lethal H5N2 avian influenza (AI) virus challenge. These findings suggest that the strategies used to induce multi-antigen-targeted mucosal immunity, such as IN/IM delivery of rAdv-AI, may be a promising approach for developing broad protective vaccines that may be more effective against the new HPAI pandemic strains. PMID:19836045

  2. Mucosal immunity induced by adenovirus-based H5N1 HPAI vaccine confers protection against a lethal H5N2 avian influenza virus challenge

    SciTech Connect

    Park, Ki Seok; Lee, Jiyeung; Ahn, So Shin; Byun, Young-Ho; Seong, Baik Lin; Baek, Yun Hee; Song, Min-Suk; Choi, Young Ki; Na, Yun Jeong; Hwang, Inhwan; Sung, Young Chul; Lee, Chang Geun

    2009-12-20

    Development of effective vaccines against highly pathogenic avian influenza (HPAI) H5N1 viruses is a global public health priority. Considering the difficulty in predicting HPAI H5N1 pandemic strains, one strategy used in their design includes the development of formulations with the capacity of eliciting broad cross-protective immunity against multiple viral antigens. To this end we constructed a replication-defective recombinant adenovirus-based avian influenza virus vaccine (rAdv-AI) expressing the codon-optimized M2eX-HA-hCD40L and the M1-M2 fusion genes from HPAI H5N1 human isolate. Although there were no significant differences in the systemic immune responses observed between the intramuscular prime-intramuscular boost regimen (IM/IM) and the intranasal prime-intramuscular boost regimen (IN/IM), IN/IM induced more potent CD8{sup +} T cell and antibody responses at mucosal sites than the IM/IM vaccination, resulting in more effective protection against lethal H5N2 avian influenza (AI) virus challenge. These findings suggest that the strategies used to induce multi-antigen-targeted mucosal immunity, such as IN/IM delivery of rAdv-AI, may be a promising approach for developing broad protective vaccines that may be more effective against the new HPAI pandemic strains.

  3. Experimental Challenge of a Peridomestic Avian Species, European Starlings ( Sturnus vulgaris ), with Novel Influenza A H7N9 Virus from China.

    PubMed

    Hall, Jeffrey S; Ip, Hon S; TeSlaa, Joshua L; Nashold, Sean W; Dusek, Robert J

    2016-07-01

    In 2013 a novel avian influenza H7N9 virus was isolated from several critically ill patients in China, and infection with this virus has since caused more than 200 human deaths. Live poultry markets are the likely locations of virus exposure to humans. Peridomestic avian species also may play important roles in the transmission and maintenance of H7N9 at live poultry markets. We experimentally challenged wild European Starlings ( Sturnus vulgaris ) with the novel H7N9 virus and measured virus excretion, clinical signs, and infectious dose. We found that European Starlings can be infected with this virus when inoculated with relatively high doses, and we predict that infected birds excrete sufficient amounts of virus to transmit to other birds, including domestic chickens. Infected European Starlings showed no clinical signs or mortality after infection with H7N9. This abundant peridomestic bird may be a source of the novel H7N9 virus in live poultry markets and may have roles in virus transmission to poultry and humans. PMID:27285413

  4. Avian influenza in shorebirds: experimental infection of ruddy turnstones (Arenaria interpres) with avian influenza virus

    USGS Publications Warehouse

    Hall, Jeffrey S.; Krauss, Scott; Franson, J. Christian; TeSlaa, Joshua L.; Nashold, Sean W.; Stallknecht, David E.; Webby, Richard J.; Webster, Robert G.

    2013-01-01

    Background: Low pathogenic avian influenza viruses (LPAIV) have been reported in shorebirds, especially at Delaware Bay, USA, during spring migration. However, data on patterns of virus excretion, minimal infectious doses, and clinical outcome are lacking. The ruddy turnstone (Arenaria interpres) is the shorebird species with the highest prevalence of influenza virus at Delaware Bay. Objectives: The primary objective of this study was to experimentally assess the patterns of influenza virus excretion, minimal infectious doses, and clinical outcome in ruddy turnstones. Methods: We experimentally challenged ruddy turnstones using a common LPAIV shorebird isolate, an LPAIV waterfowl isolate, or a highly pathogenic H5N1 avian influenza virus. Cloacal and oral swabs and sera were analyzed from each bird. Results: Most ruddy turnstones had pre-existing antibodies to avian influenza virus, and many were infected at the time of capture. The infectious doses for each challenge virus were similar (103·6–104·16 EID50), regardless of exposure history. All infected birds excreted similar amounts of virus and showed no clinical signs of disease or mortality. Influenza A-specific antibodies remained detectable for at least 2 months after inoculation. Conclusions: These results provide a reference for interpretation of surveillance data, modeling, and predicting the risks of avian influenza transmission and movement in these important hosts.

  5. Development of Stable Influenza Vaccine Powder Formulations: Challenges and Possibilities

    PubMed Central

    Amorij, J-P.; Huckriede, A.; Wilschut, J.; Frijlink, H. W.

    2008-01-01

    Influenza vaccination represents the cornerstone of influenza prevention. However, today all influenza vaccines are formulated as liquids that are unstable at ambient temperatures and have to be stored and distributed under refrigeration. In order to stabilize influenza vaccines, they can be brought into the dry state using suitable excipients, stabilizers and drying processes. The resulting stable influenza vaccine powder is independent of cold-chain facilities. This can be attractive for the integration of the vaccine logistics with general drug distribution in Western as well as developing countries. In addition, a stockpile of stable vaccine formulations of potential vaccines against pandemic viruses can provide an immediate availability and simple distribution of vaccine in a pandemic outbreak. Finally, in the development of new needle-free dosage forms, dry and stable influenza vaccine powder formulations can facilitate new or improved targeting strategies for the vaccine compound. This review represents the current status of dry stable inactivated influenza vaccine development. Attention is given to the different influenza vaccine types (i.e. whole inactivated virus, split, subunit or virosomal vaccine), the rationale and need for stabilized influenza vaccines, drying methods by which influenza vaccines can be stabilized (i.e. lyophilization, spray drying, spray-freeze drying, vacuum drying or supercritical fluid drying), the current status of dry influenza vaccine development and the challenges for ultimate market introduction of a stable and effective dry-powder influenza vaccine. PMID:18338241

  6. Evaluation of Antihemagglutinin and Antineuraminidase Antibodies as Correlates of Protection in an Influenza A/H1N1 Virus Healthy Human Challenge Model

    PubMed Central

    Shaw, Pamela A.; Han, Alison; Czajkowski, Lindsay; Reed, Susan; Athota, Rani; Bristol, Tyler; Fargis, Sarah; Risos, Kyle; Powers, John H.; Davey, Richard T.; Taubenberger, Jeffery K.

    2016-01-01

    ABSTRACT Despite long-term investment, influenza continues to be a significant worldwide problem. The cornerstone of protection remains vaccination, and approved vaccines seek to elicit a hemagglutination inhibition (HAI) titer of ≥1:40 as the primary correlate of protection. However, recent poor vaccine performance raises questions regarding the protection afforded and whether other correlates of protection should be targeted. A healthy volunteer challenge study was performed with a wild-type 2009 A(H1N1)pdm influenza A challenge virus at the NIH Clinical Center to evaluate two groups of participants with HAI titers of ≥1:40 and <1:40. The primary objective was to determine whether participants with HAI titers of ≥1:40 were less likely to develop mild to moderate influenza disease (MMID) after intranasal inoculation. HAI titers of ≥1:40 were protective against MMID but did not reduce the incidence of symptoms alone. Although the baseline HAI titer correlated with some reduction in disease severity measures, overall, the baseline NAI titer correlated more significantly with all disease severity metrics and had a stronger independent effect on outcome. This study demonstrates the importance of examining other immunological correlates of protection rather than solely HAI titers. This challenge study confirms the importance of NAI titer as a correlate and for the first time establishes that it can be an independent predictor of reduction of all aspects of influenza disease. This suggests that NAI titer may play a more significant role than previously thought and that neuraminidase immunity should be considered when studying susceptibility after vaccination and as a critical target in future influenza vaccine platforms. PMID:27094330

  7. A Defective Interfering Influenza RNA Inhibits Infectious Influenza Virus Replication in Human Respiratory Tract Cells: A Potential New Human Antiviral.

    PubMed

    Smith, Claire M; Scott, Paul D; O'Callaghan, Christopher; Easton, Andrew J; Dimmock, Nigel J

    2016-01-01

    Defective interfering (DI) viruses arise during the replication of influenza A virus and contain a non-infective version of the genome that is able to interfere with the production of infectious virus. In this study we hypothesise that a cloned DI influenza A virus RNA may prevent infection of human respiratory epithelial cells with infection by influenza A. The DI RNA (244/PR8) was derived by a natural deletion process from segment 1 of influenza A/PR/8/34 (H1N1); it comprises 395 nucleotides and is packaged in the DI virion in place of a full-length genome segment 1. Given intranasally, 244/PR8 DI virus protects mice and ferrets from clinical influenza caused by a number of different influenza A subtypes and interferes with production of infectious influenza A virus in cells in culture. However, evidence that DI influenza viruses are active in cells of the human respiratory tract is lacking. Here we show that 244/PR8 DI RNA is replicated by an influenza A challenge virus in human lung diploid fibroblasts, bronchial epithelial cells, and primary nasal basal cells, and that the yield of challenge virus is significantly reduced in a dose-dependent manner indicating that DI influenza virus has potential as a human antiviral. PMID:27556481

  8. A Defective Interfering Influenza RNA Inhibits Infectious Influenza Virus Replication in Human Respiratory Tract Cells: A Potential New Human Antiviral

    PubMed Central

    Smith, Claire M.; Scott, Paul D.; O’Callaghan, Christopher; Easton, Andrew J.; Dimmock, Nigel J.

    2016-01-01

    Defective interfering (DI) viruses arise during the replication of influenza A virus and contain a non-infective version of the genome that is able to interfere with the production of infectious virus. In this study we hypothesise that a cloned DI influenza A virus RNA may prevent infection of human respiratory epithelial cells with infection by influenza A. The DI RNA (244/PR8) was derived by a natural deletion process from segment 1 of influenza A/PR/8/34 (H1N1); it comprises 395 nucleotides and is packaged in the DI virion in place of a full-length genome segment 1. Given intranasally, 244/PR8 DI virus protects mice and ferrets from clinical influenza caused by a number of different influenza A subtypes and interferes with production of infectious influenza A virus in cells in culture. However, evidence that DI influenza viruses are active in cells of the human respiratory tract is lacking. Here we show that 244/PR8 DI RNA is replicated by an influenza A challenge virus in human lung diploid fibroblasts, bronchial epithelial cells, and primary nasal basal cells, and that the yield of challenge virus is significantly reduced in a dose-dependent manner indicating that DI influenza virus has potential as a human antiviral. PMID:27556481

  9. Novel hemagglutinin-based influenza virus inhibitors

    PubMed Central

    Shen, Xintian; Zhang, Xuanxuan

    2013-01-01

    Influenza virus has caused seasonal epidemics and worldwide pandemics, which caused tremendous loss of human lives and socioeconomics. Nowadays, only two classes of anti-influenza drugs, M2 ion channel inhibitors and neuraminidase inhibitors respectively, are used for prophylaxis and treatment of influenza virus infection. Unfortunately, influenza virus strains resistant to one or all of those drugs emerge frequently. Hemagglutinin (HA), the glycoprotein in influenza virus envelope, plays a critical role in viral binding, fusion and entry processes. Therefore, HA is a promising target for developing anti-influenza drugs, which block the initial entry step of viral life cycle. Here we reviewed recent understanding of conformational changes of HA in protein folding and fusion processes, and the discovery of HA-based influenza entry inhibitors, which may provide more choices for preventing and controlling potential pandemics caused by multi-resistant influenza viruses. PMID:23977436

  10. Experimental challenge and pathology of highly pathogenic avian influenza virus H5N1 in dunlin (Calidris alpina), an intercontinental migrant shorebird species

    USGS Publications Warehouse

    Hall, J.S.; Franson, J.C.; Gill, R.E.; Meteyer, C.U.; Teslaa, J.L.; Nashold, S.; Dusek, R.J.; Ip, H.S.

    2011-01-01

    Background Shorebirds (Charadriiformes) are considered one of the primary reservoirs of avian influenza. Because these species are highly migratory, there is concern that infected shorebirds may be a mechanism by which highly pathogenic avian influenza virus (HPAIV) H5N1 could be introduced into North America from Asia. Large numbers of dunlin (Calidris alpina) migrate from wintering areas in central and eastern Asia, where HPAIV H5N1 is endemic, across the Bering Sea to breeding areas in Alaska. Low pathogenic avian influenza virus has been previously detected in dunlin, and thus, dunlin represent a potential risk to transport HPAIV to North America. To date no experimental challenge studies have been performed in shorebirds. Methods Wild dunlin were inoculated intranasally and intrachoanally various doses of HPAIV H5N1. The birds were monitored daily for virus excretion, disease signs, morbidity, and mortality. Results The infectious dose of HPAIV H5N1 in dunlin was determined to be 101.7 EID50/100 ??l and that the lethal dose was 101.83 EID50/100 ??l. Clinical signs were consistent with neurotropic disease, and histochemical analyses revealed that infection was systemic with viral antigen and RNA most consistently found in brain tissues. Infected birds excreted relatively large amounts of virus orally (104 EID50) and smaller amounts cloacally. Conclusions Dunlin are highly susceptible to infection with HPAIV H5N1. They become infected after exposure to relatively small doses of the virus and if they become infected, they are most likely to suffer mortality within 3-5days. These results have important implications regarding the risks of transport and transmission of HPAIV H5N1 to North America by this species and raises questions for further investigation. Published 2011. This article is a US Government work and is in the public domain in the USA.

  11. New vaccines against influenza virus

    PubMed Central

    Lee, Young-Tae; Kim, Ki-Hye; Ko, Eun-Ju; Lee, Yu-Na; Kim, Min-Chul; Kwon, Young-Man; Tang, Yinghua; Cho, Min-Kyoung; Lee, Youn-Jeong

    2014-01-01

    Vaccination is one of the most effective and cost-benefit interventions that prevent the mortality and reduce morbidity from infectious pathogens. However, the licensed influenza vaccine induces strain-specific immunity and must be updated annually based on predicted strains that will circulate in the upcoming season. Influenza virus still causes significant health problems worldwide due to the low vaccine efficacy from unexpected outbreaks of next epidemic strains or the emergence of pandemic viruses. Current influenza vaccines are based on immunity to the hemagglutinin antigen that is highly variable among different influenza viruses circulating in humans and animals. Several scientific advances have been endeavored to develop universal vaccines that will induce broad protection. Universal vaccines have been focused on regions of viral proteins that are highly conserved across different virus subtypes. The strategies of universal vaccines include the matrix 2 protein, the hemagglutinin HA2 stalk domain, and T cell-based multivalent antigens. Supplemented and/or adjuvanted vaccination in combination with universal target antigenic vaccines would have much promise. This review summarizes encouraging scientific advances in the field with a focus on novel vaccine designs. PMID:24427759

  12. Selecting Viruses for the Seasonal Influenza Vaccine

    MedlinePlus

    ... which viruses are selected for use in vaccine production? The influenza viruses in the seasonal flu vaccine ... to get a good vaccine virus for vaccine production? There are a number of factors that can ...

  13. Detection of influenza C virus but not influenza D virus in Scottish respiratory samples

    PubMed Central

    Smith, Donald B.; Gaunt, Eleanor R.; Digard, Paul; Templeton, Kate; Simmonds, Peter

    2016-01-01

    Background A newly proposed genus of influenza virus (influenza D) is associated with respiratory disease in pigs and cattle. The novel virus is most closely related to human influenza C virus and can infect ferrets but infection has not been reported in humans. Objectives To ascertain if influenza D virus can be detected retrospectively in patient respiratory samples. Study design 3300 human respiratory samples from Edinburgh, Scotland, covering the period 2006–2008, were screened in pools of 10 by RT-PCR using primers capable of detecting both influenza C and D viruses. Results Influenza D was not detected in any sample. Influenza C was present in 6 samples (0.2%), compared with frequencies of 3.3% and 0.9% for influenza A and B viruses from RT-PCR testing of respiratory samples over the same period. Influenza C virus was detected in samples from individuals <2 years or >45 years old, with cases occurring throughout the year. Phylogenetic analysis of nearly complete sequences of all seven segments revealed the presence of multiple, reassortant lineages. Conclusion We were unable to detect viruses related to influenza D virus in human respiratory samples. Influenza C virus was less prevalent than influenza A and B viruses, was associated with mild disease in the young (<2 years) and old (>45 years) and comprised multiple, reassortant lineages. Inclusion of influenza C virus as part of a diagnostic testing panel for respiratory infections would be of limited additional value. PMID:26655269

  14. Cryptoporus volvatus Extract Inhibits Influenza Virus Replication In Vitro and In Vivo

    PubMed Central

    Si, Jianyong; Liu, Jinhua; Sun, Guibo; Sun, Xiaobo; Cao, Li

    2014-01-01

    Influenza virus is the cause of significant morbidity and mortality, posing a serious health threat worldwide. Here, we evaluated the antiviral activities of Cryptoporus volvatus extract on influenza virus infection. Our results demonstrated that the Cryptoporus volvatus extract inhibited different influenza virus strain replication in MDCK cells. Time course analysis indicated that the extract exerted its inhibition at earlier and late stages in the replication cycle of influenza virus. Subsequently, we confirmed that the extract suppressed virus internalization into and released from cells. Moreover, the extract significantly reduced H1N1/09 influenza virus load in lungs and dramatically decreased lung lesions in mice. And most importantly, the extract protected mice from lethal challenge with H1N1/09 influenza virus. Our results suggest that the Cryptoporus volvatus extract could be a potential candidate for the development of a new anti-influenza virus therapy. PMID:25437846

  15. Influenza A virus recycling revisited.

    PubMed Central

    Dowdle, W. R.

    1999-01-01

    Current textbooks link influenza pandemics to influenza A virus subtypes H2 (1889-91), H3 (1990), H1 (1918-20), H2 (1957-58) and H3 (1968), a pattern suggesting subtype recycling in humans. Since H1 reappeared in 1977, whatever its origin, some workers feel that H2 is the next pandemic candidate. This report reviews the publications on which the concept of influenza A virus subtype recycling is based and concludes that the data are inconsistent with the purported sequence of events. The three influenza pandemics prior to 1957-58 were linked with subtypes through retrospective studies of sera from the elderly, or through seroarchaeology. The pandemic seroarchaeological model for subtype H1 has been validated by the recent recovery of swine virus RNA fragments from persons who died from influenza in 1918. Application of the model to pre-existing H3 antibody among the elderly links the H3 subtype to the pandemic of 1889-91, not that of 1900 as popularly quoted. Application of the model to pre-existing H2 antibody among the elderly fails to confirm that this subtype caused a pandemic in the late 1800's, a finding which is consistent with age-related excess mortality patterns during the pandemics of 1957 (H2) and 1968 (H3). H2 variants should be included in pandemic planning for a number of reasons, but not because of evidence of recycling. It is not known when the next pandemic will occur or which of the 15 (or more) haemagglutinin subtypes will be involved. Effective global surveillance remains the key to influenza preparedness. PMID:10593030

  16. Evolution and ecology of influenza A viruses.

    PubMed Central

    Webster, R G; Bean, W J; Gorman, O T; Chambers, T M; Kawaoka, Y

    1992-01-01

    In this review we examine the hypothesis that aquatic birds are the primordial source of all influenza viruses in other species and study the ecological features that permit the perpetuation of influenza viruses in aquatic avian species. Phylogenetic analysis of the nucleotide sequence of influenza A virus RNA segments coding for the spike proteins (HA, NA, and M2) and the internal proteins (PB2, PB1, PA, NP, M, and NS) from a wide range of hosts, geographical regions, and influenza A virus subtypes support the following conclusions. (i) Two partly overlapping reservoirs of influenza A viruses exist in migrating waterfowl and shorebirds throughout the world. These species harbor influenza viruses of all the known HA and NA subtypes. (ii) Influenza viruses have evolved into a number of host-specific lineages that are exemplified by the NP gene and include equine Prague/56, recent equine strains, classical swine and human strains, H13 gull strains, and all other avian strains. Other genes show similar patterns, but with extensive evidence of genetic reassortment. Geographical as well as host-specific lineages are evident. (iii) All of the influenza A viruses of mammalian sources originated from the avian gene pool, and it is possible that influenza B viruses also arose from the same source. (iv) The different virus lineages are predominantly host specific, but there are periodic exchanges of influenza virus genes or whole viruses between species, giving rise to pandemics of disease in humans, lower animals, and birds. (v) The influenza viruses currently circulating in humans and pigs in North America originated by transmission of all genes from the avian reservoir prior to the 1918 Spanish influenza pandemic; some of the genes have subsequently been replaced by others from the influenza gene pool in birds. (vi) The influenza virus gene pool in aquatic birds of the world is probably perpetuated by low-level transmission within that species throughout the year. (vii

  17. Impact of route of exposure and challenge dose on the pathogenesis of H7N9 low pathogenicity avian influenza virus in chickens

    PubMed Central

    Spackman, Erica; Pantin-Jackwood, Mary; Swayne, David E.; Suarez, David L.; Kapczynski, Darrell R.

    2015-01-01

    H7N9 influenza A first caused human infections in early 2013 in China. Virus genetics, histories of patient exposures to poultry, and previous experimental studies suggest the source of the virus is a domestic avian species, such as chickens. In order to better understand the ecology of this H7N9 in chickens, we evaluated the infectious dose and pathogenesis of A/Anhui/1/2013 H7N9 in two common breeds of chickens, White Leghorns (table-egg layers) and White Plymouth Rocks (meat chickens). No morbidity or mortality were observed with doses of 106 or 108 EID50 per bird when administered by the upper-respiratory route, and the mean infectious dose (106 EID50) was higher than expected, suggesting that the virus is poorly adapted to chickens. Virus was shed at higher titers and spread to the kidneys in chickens inoculated by the intravenous route. Challenge experiments with three other human-origin H7N9 viruses showed a similar pattern of virus replication. PMID:25662310

  18. Influenza virus neuraminidase: structure, antibodies, and inhibitors.

    PubMed Central

    Colman, P. M.

    1994-01-01

    The determination of the 3-dimensional structure of the influenza virus neuraminidase in 1983 has served as a platform for understanding interactions between antibodies and protein antigens, for investigating antigenic variation in influenza viruses, and for devising new inhibitors of the enzyme. That work is reviewed here, together with more recent developments that have resulted in one of the inhibitors entering clinical trials as an anti-influenza virus drug. PMID:7849585

  19. Optimisations and Challenges Involved in the Creation of Various Bioluminescent and Fluorescent Influenza A Virus Strains for In Vitro and In Vivo Applications

    PubMed Central

    Herfst, Sander; Bestebroer, Theo M.; Vaes, Vincent P.; van der Hoeven, Barbara; Koster, Abraham J.; Kremers, Gert-Jan; Scott, Dana P.; Gultyaev, Alexander P.; Sorell, Erin M.; de Graaf, Miranda; Bárcena, Montserrat; Rimmelzwaan, Guus F.; Fouchier, Ron A.

    2015-01-01

    Bioluminescent and fluorescent influenza A viruses offer new opportunities to study influenza virus replication, tropism and pathogenesis. To date, several influenza A reporter viruses have been described. These strategies typically focused on a single reporter gene (either bioluminescent or fluorescent) in a single virus backbone. However, whilst bioluminescence is suited to in vivo imaging, fluorescent viruses are more appropriate for microscopy. Therefore, the idea l reporter virus varies depending on the experiment in question, and it is important that any reporter virus strategy can be adapted accordingly. Herein, a strategy was developed to create five different reporter viruses in a single virus backbone. Specifically, enhanced green fluorescent protein (eGFP), far-red fluorescent protein (fRFP), near-infrared fluorescent protein (iRFP), Gaussia luciferase (gLUC) and firefly luciferase (fLUC) were inserted into the PA gene segment of A/PR/8/34 (H1N1). This study provides a comprehensive characterisation of the effects of different reporter genes on influenza virus replication and reporter activity. In vivo reporter gene expression, in lung tissues, was only detected for eGFP, fRFP and gLUC expressing viruses. In vitro, the eGFP-expressing virus displayed the best reporter stability and could be used for correlative light electron microscopy (CLEM). This strategy was then used to create eGFP-expressing viruses consisting entirely of pandemic H1N1, highly pathogenic avian influenza (HPAI) H5N1 and H7N9. The HPAI H5N1 eGFP-expressing virus infected mice and reporter gene expression was detected, in lung tissues, in vivo. Thus, this study provides new tools and insights for the creation of bioluminescent and fluorescent influenza A reporter viruses. PMID:26241861

  20. Efficacy of canine influenza virus (H3N8) vaccine to decrease severity of clinical disease after co-challenge with canine influenza virus and Streptococcus equi subsp. Zooepidemicus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since first emerging into the North American canine population in 2004, canine influenza virus (CIV) subtype H3N8 has shown horizontal transmission among dogs, with a high level of adaptation to this species. Severity of disease is variable, and co-infection by other respiratory pathogens is an impo...

  1. Expression of H5 hemagglutinin vaccine antigen in common duckweed (Lemna minor) protects against H5N1 high pathogenicity avian influenza virus challenge in immunized chickens.

    PubMed

    Bertran, Kateri; Thomas, Colleen; Guo, Xuan; Bublot, Michel; Pritchard, Nikki; Regan, Jeffrey T; Cox, Kevin M; Gasdaska, John R; Dickey, Lynn F; Kapczynski, Darrell R; Swayne, David E

    2015-07-01

    A synthetic hemagglutinin (HA) gene from the highly pathogenic avian influenza (HPAI) virus A/chicken/Indonesia/7/2003 (H5N1) (Indo/03) was expressed in aquatic plant Lemna minor (rLemna-HA). In Experiment 1, efficacy of rLemna-HA was tested on birds immunized with 0.2μg or 2.3 μg HA and challenged with 10(6) mean chicken embryo infectious doses (EID50) of homologous virus strain. Both dosages of rLemna-HA conferred clinical protection and dramatically reduced viral shedding. Almost all the birds immunized with either dosage of rLemna-HA elicited HA antibody titers against Indo/03 antigen, suggesting an association between levels of anti-Indo/03 antibodies and protection. In Experiment 2, efficacy of rLemna-HA was tested on birds immunized with 0.9 μg or 2.2 μg HA and challenged with 10(6) EID50 of heterologous H5N1 virus strains A/chicken/Vietnam/NCVD-421/2010 (VN/10) or A/chicken/West Java/PWT-WIJ/2006 (PWT/06). Birds challenged with VN/10 exhibited 100% survival regardless of immunization dosage, while birds challenged with PWT/06 had 50% and 30% mortality at 0.9 μg HA and 2.2 μg HA, respectively. For each challenge virus, viral shedding titers from 2.2 μg HA vaccinated birds were significantly lower than those from 0.9μg HA vaccinated birds, and titers from both immunized groups were in turn significantly lower than those from sham vaccinated birds. Even if immunized birds elicited HA titers against the vaccine antigen Indo/03, only the groups challenged with VN/10 developed humoral immunity against the challenge antigen. None (rLemna-HA 0.9 μg HA) and 40% (rLemna-HA 2.2 μg HA) of the immunized birds challenged with PWT/06 elicited pre-challenge antibody titers, respectively. In conclusion, Lemna-expressed HA demonstrated complete protective immunity against homologous challenge and suboptimal protection against heterologous challenge, the latter being similar to results from inactivated whole virus vaccines. Transgenic duckweed-derived HA could be a

  2. Immunogenicity of avian influenza H7N9 virus in birds: Identification of viral epitopes recognized by the immune system following vaccination and challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In March of 2013, the first cases of H7N9 influenza were reported in humans in China and shortly thereafter the virus was isolated from poultry in live bird markets. In 2014, a second wave of human infections occurred with similar mortality rates. The genetic composition of these H7N9 influenza vi...

  3. A brief introduction to influenza A virus in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A viruses (IAV) of the Orthomyxoviridae virus family cause one of the most important respiratory diseases in pigs as well as humans. Repeated outbreaks and rapid spread of genetically and antigenically distinct IAVs represent a considerable challenge for animal production and public health...

  4. DIVA vaccination strategies for avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination for both low pathogenic and highly pathogenic avian influenza is commonly used for countries that have been endemic for avian influenza influenza virus, but stamping out policies are common for countries that are normally free of the disease. Stamping out policies of euthanizing infecte...

  5. Heightened adaptive immune responses following vaccination with a temperature-sensitive, live-attenuated influenza virus compared to adjuvanted, whole-inactivated virus in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the United States there are currently two influenza vaccine platforms approved for use in humans - conventional inactivated virus and live-attenuated influenza virus (LAIV). One of the major challenges for influenza A virus (IAV) vaccination is designing a platform that provides protection across...

  6. The Carbomer-Lecithin Adjuvant Adjuplex Has Potent Immunoactivating Properties and Elicits Protective Adaptive Immunity against Influenza Virus Challenge in Mice.

    PubMed

    Wegmann, Frank; Moghaddam, Amin E; Schiffner, Torben; Gartlan, Kate H; Powell, Timothy J; Russell, Rebecca A; Baart, Matthijs; Carrow, Emily W; Sattentau, Quentin J

    2015-09-01

    The continued discovery and development of adjuvants for vaccine formulation are important to safely increase potency and/or reduce the antigen doses of existing vaccines and tailor the adaptive immune response to newly developed vaccines. Adjuplex is a novel adjuvant platform based on a purified lecithin and carbomer homopolymer. Here, we analyzed the adjuvant activity of Adjuplex in mice for the soluble hemagglutinin (HA) glycoprotein of influenza A virus. The titration of Adjuplex revealed an optimal dose of 1% for immunogenicity, eliciting high titers of HA-specific IgG but inducing no significant weight loss. At this dose, Adjuplex completely protected mice from an otherwise lethal influenza virus challenge and was at least as effective as the adjuvants monophosphoryl lipid A (MPL) and alum in preventing disease. Adjuplex elicited balanced Th1-/Th2-type immune responses with accompanying cytokines and triggered antigen-specific CD8(+) T-cell proliferation. The use of the peritoneal inflammation model revealed that Adjuplex recruited dendritic cells (DCs), monocytes, and neutrophils in the context of innate cytokine and chemokine secretion. Adjuplex neither triggered classical maturation of DCs nor activated a pathogen recognition receptor (PRR)-expressing NF-κB reporter cell line, suggesting a mechanism of action different from that reported for classical pathogen-associated molecular pattern (PAMP)-activated innate immunity. Taken together, these data reveal Adjuplex to be a potent and well-tolerated adjuvant with application for subunit vaccines. PMID:26135973

  7. The Carbomer-Lecithin Adjuvant Adjuplex Has Potent Immunoactivating Properties and Elicits Protective Adaptive Immunity against Influenza Virus Challenge in Mice

    PubMed Central

    Wegmann, Frank; Moghaddam, Amin E.; Schiffner, Torben; Gartlan, Kate H.; Powell, Timothy J.; Russell, Rebecca A.; Baart, Matthijs; Carrow, Emily W.

    2015-01-01

    The continued discovery and development of adjuvants for vaccine formulation are important to safely increase potency and/or reduce the antigen doses of existing vaccines and tailor the adaptive immune response to newly developed vaccines. Adjuplex is a novel adjuvant platform based on a purified lecithin and carbomer homopolymer. Here, we analyzed the adjuvant activity of Adjuplex in mice for the soluble hemagglutinin (HA) glycoprotein of influenza A virus. The titration of Adjuplex revealed an optimal dose of 1% for immunogenicity, eliciting high titers of HA-specific IgG but inducing no significant weight loss. At this dose, Adjuplex completely protected mice from an otherwise lethal influenza virus challenge and was at least as effective as the adjuvants monophosphoryl lipid A (MPL) and alum in preventing disease. Adjuplex elicited balanced Th1-/Th2-type immune responses with accompanying cytokines and triggered antigen-specific CD8+ T-cell proliferation. The use of the peritoneal inflammation model revealed that Adjuplex recruited dendritic cells (DCs), monocytes, and neutrophils in the context of innate cytokine and chemokine secretion. Adjuplex neither triggered classical maturation of DCs nor activated a pathogen recognition receptor (PRR)-expressing NF-κB reporter cell line, suggesting a mechanism of action different from that reported for classical pathogen-associated molecular pattern (PAMP)-activated innate immunity. Taken together, these data reveal Adjuplex to be a potent and well-tolerated adjuvant with application for subunit vaccines. PMID:26135973

  8. Protection against divergent influenza H1N1 virus by a centralized influenza hemagglutinin.

    PubMed

    Weaver, Eric A; Rubrum, Adam M; Webby, Richard J; Barry, Michael A

    2011-01-01

    Influenza poses a persistent worldwide threat to the human population. As evidenced by the 2009 H1N1 pandemic, current vaccine technologies are unable to respond rapidly to this constantly diverging pathogen. We tested the utility of adenovirus (Ad) vaccines expressing centralized consensus influenza antigens. Ad vaccines were produced within 2 months and protected against influenza in mice within 3 days of vaccination. Ad vaccines were able to protect at doses as low as 10(7) virus particles/kg indicating that approximately 1,000 human doses could be rapidly generated from standard Ad preparations. To generate broadly cross-reactive immune responses, centralized consensus antigens were constructed against H1 influenza and against H1 through H5 influenza. Twenty full-length H1 HA sequences representing the main branches of the H1 HA phylogenetic tree were used to create a synthetic centralized gene, HA1-con. HA1-con minimizes the degree of sequence dissimilarity between the vaccine and existing circulating viruses. The centralized H1 gene, HA1-con, induced stronger immune responses and better protection against mismatched virus challenges as compared to two wildtype H1 genes. HA1-con protected against three genetically diverse lethal influenza challenges. When mice were challenged with 1934 influenza A/PR/8/34, HA1-con protected 100% of mice while vaccine generated from 2009 A/TX/05/09 only protected 40%. Vaccination with 1934 A/PR/8/34 and 2009 A/TX/05/09 protected 60% and 20% against 1947 influenza A/FM/1/47, respectively, whereas 80% of mice vaccinated with HA1-con were protected. Notably, 80% of mice challenged with 2009 swine flu isolate A/California/4/09 were protected by HA1-con vaccination. These data show that HA1-con in Ad has potential as a rapid and universal vaccine for H1N1 influenza viruses. PMID:21464940

  9. Influenza virus activation of the interferon system

    PubMed Central

    Killip, Marian J.; Fodor, Ervin; Randall, Richard E.

    2015-01-01

    The host interferon (IFN) response represents one of the first barriers that influenza viruses must surmount in order to establish an infection. Many advances have been made in recent years in understanding the interactions between influenza viruses and the interferon system. In this review, we summarise recent work regarding activation of the type I IFN response by influenza viruses, including attempts to identify the viral RNA responsible for IFN induction, the stage of the virus life cycle at which it is generated and the role of defective viruses in this process. PMID:25678267

  10. Virulence determinants of pandemic influenza viruses

    PubMed Central

    Tscherne, Donna M.; García-Sastre, Adolfo

    2011-01-01

    Influenza A viruses cause recurrent, seasonal epidemics and occasional global pandemics with devastating levels of morbidity and mortality. The ability of influenza A viruses to adapt to various hosts and undergo reassortment events ensures constant generation of new strains with unpredictable degrees of pathogenicity, transmissibility, and pandemic potential. Currently, the combination of factors that drives the emergence of pandemic influenza is unclear, making it impossible to foresee the details of a future outbreak. Identification and characterization of influenza A virus virulence determinants may provide insight into genotypic signatures of pathogenicity as well as a more thorough understanding of the factors that give rise to pandemics. PMID:21206092

  11. Recombinant adenovirus encoding the HA gene from swine H3N2 influenza virus partially protects mice from challenge with heterologous virus: A/HK/1/68 (H3N2).

    PubMed

    Tang, M; Harp, J A; Wesley, R D

    2002-11-01

    Immunization with recombinant adenoviral vaccine that induces potent immunity has been applied to many infectious diseases. We report here developing a recombinant adenoviral vaccine encoding the HA gene from swine H3N2 influenza virus (SIV). Two replication-defective recombinant adenoviruses were generated: (1) rAd-HA: recombinant adenovirus encoding the HA gene from swine H3N2 influenza virus, and (2) rAd-vector: a control recombinant adenovirus containing adenovirus and transfer plasmids without a foreign HA gene. Mice given rAd-HA developed high titers of neutralizing and hemagglutination inhibition antibodies to SIV in comparison to mice inoculated with rAd-vector or PBS as early as 2 weeks after immunization, and these antibodies were substantially increased in the mice given rAd-HA within the next 3 weeks following the first dose. However, these antibodies were not able to neutralize the virus, A/HK/68 (H3N2), used for challenge. Nonetheless mice immunized with one or two doses of rAd-HA were protected from lethal challenge with heterologous virus, A/HK/1/68 (H3N2). A statistically significant ( P < 0.03) difference between survival rates of rAd-HA mice vs. rAd-vector or PBS mice was observed. PMID:12417948

  12. A brief introduction to avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) is caused by a type A influenza virus isolated from and adapted to an avian host. This chapter covers the basic physicochemical aspects of AIV including; virus family and properties, subtype classification; basic molecular biology and genetics. The avian host range and ecology...

  13. Swine influenza virus: epidemiology and vaccine concerns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction. Swine influenza virus (SIV) is a primary cause of respiratory disease in swine and a component of the porcine respiratory disease complex (PRDC). Influenza viruses are an important health and economic concern for swine producers throughout the world. Swine operations may be affected by...

  14. The receptor preference of influenza viruses

    PubMed Central

    Meng, Bo; Marriott, Anthony C.; Dimmock, Nigel J.

    2010-01-01

    Please cite this paper as: Meng et al. (2010) The receptor preference of influenza viruses. Influenza and Other Respiratory Viruses 4(3), 147–153. Objectives  The cell surface receptor used by an influenza virus to infect that cell is an N‐acetyl neuraminic acid (NANA) residue terminally linked by an alpha2,3 or alpha2,6 bond to a carbohydrate moiety of a glycoprotein or glycolipid. Our aim was to determine a quick and technically simple method to determine cell receptor usage by whole influenza A virus particles. Methods  We employed surface plasmon resonance to detect the binding of viruses to fetuin, a naturally occurring glycoprotein that has both alpha2,3‐ and alpha2,6‐linked NANA, and free 3′‐sialyllactose or 6′‐sialyllactose to compete virus binding. All virus stocks were produced in embryonated chicken’s eggs. Results  The influenza viruses tested bound preferentially to NANAalpha2,3Gal or to NANAalpha2,6Gal, or showed no preference. Two PR8 viruses had different binding preferences. Binding preferences of viruses correlated well with their known biological properties. Conclusions  Our data suggest that it is not easy to predict receptor usage by influenza viruses. However, direct experimental determination as described here can inform experiments concerned with viral pathogenesis, biology and structure. In principle, the methodology can be used for any virus that binds to a terminal NANA residue. PMID:20409211

  15. Live, attenuated influenza virus (LAIV) vehicles are strong inducers of immunity toward influenza B virus

    PubMed Central

    Huber, Victor C.; Kleimeyer, Loren H.; McCullers, Jonathan A.

    2008-01-01

    Historically, vaccines developed toward influenza viruses of the B type using methodologies developed for influenza A viruses as a blueprint have not been equally efficacious or effective. Because most influenza research and public attention concerns influenza A viruses, these shortcomings have not been adequately addressed. In this manuscript, we utilized different influenza vaccine vehicles to compare immunogenicity and protection in mice and ferrets after vaccination against an influenza B virus. We report that plasmid DNA vaccines demonstrate low immunogenicity profiles and poor protection compared to either whole, inactivated influenza virus (IIV) or, live, attenuated influenza virus (LAIV) vaccines. When mixed prime:boost regimens using LAIV and IIV were studied, we observed a boosting effect in mice after priming with LAIV that was not seen when IIV was used as the prime. In ferrets LAIV induced high antibody titers after a single dose and provided a boost in IIV-primed animals. Regimens including LAIV as a prime demonstrated enhanced protection, and adjuvantation was required for efficacy using the IIV preparation. Our results differ from generally accepted influenza A virus vaccine models, and argue that strategies for control of influenza B virus should be considered separately from those for influenza A virus. PMID:18708106

  16. A Novel Influenza Virus Hemagglutinin-Respiratory Syncytial Virus (RSV) Fusion Protein Subunit Vaccine against Influenza and RSV

    PubMed Central

    Turner, Tiffany M.; Jones, Les P.; Tompkins, S. Mark

    2013-01-01

    Influenza A virus and respiratory syncytial virus (RSV) cause substantial morbidity and mortality afflicting the ends of the age spectrum during the autumn through winter months in the United States. The benefit of vaccination against RSV and influenza using a subunit vaccine to enhance immunity and neutralizing antibody was investigated. Influenza virus hemagglutinin (HA) and RSV fusion (F) protein were tested as vaccine components alone and in combination to explore the adjuvant properties of RSV F protein on HA immunity. Mice vaccinated with HA and F exhibited robust immunity that, when challenged, had reduced viral burden for both influenza and RSV. These studies show an enhancing and cross-protective benefit of F protein for anti-HA immunity. PMID:23903841

  17. An H1-H3 chimeric influenza virosome confers complete protection against lethal challenge with PR8 (H1N1) and X47 (H3N2) viruses in mice.

    PubMed

    Abdoli, Asghar; Soleimanjahi, Hoorieh; Tavassoti Kheiri, Masoumeh; Jamali, Abbas; Mazaheri, Vahideh; Abdollahpour Alitappeh, Meghdad

    2014-12-01

    Annual health threats and economic damages caused by influenza virus are still a main concern of the World Health Organization and other health departments all over the world. An influenza virosome is a highly efficient immunomodulating carrier mimicking the natural antigen presentation pathway and has shown an excellent tolerability profile due to its biocompatibility and purity. The major purpose of this study was to construct a new chimeric virosome influenza vaccine containing hemagglutinin (HA) and neuraminidase (NA) proteins derived from the A/PR/8/1934 (H1N1) (PR8) and A/X/47 (H3N2) (X47) viruses, and to evaluate its efficacy as a vaccine candidate in mice. A single intramuscular vaccination with the chimeric virosomes provided complete protection against lethal challenge with the PR8 and X47 viruses. The chimeric virosomes induced high IgG antibody responses as well as hemagglutination inhibition (HAI) titers. HAI titers following the chimeric virosome vaccination were at the same level as the whole inactivated influenza vaccine. Mice immunized with the chimeric virosomes displayed considerably less weight loss and exhibited significantly reduced viral load in their lungs compared with the controls. The chimeric virosomes can be used as an innovative vaccine formulation to confer protection against a broad range of influenza viruses. PMID:25066138

  18. Live attenuated influenza A virus vaccine protects against heterologous challenge with A(H1N1)pdm09 without inducing vaccine associated enhanced respiratory disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A virus (IAV) vaccines that provide broad cross-protection against antigenic variants are necessary to prevent infection and shedding of the wide array of IAV cocirculating in swine. Whole inactivated virus (WIV) vaccines provide only partial protection against IAV with substantial antigen...

  19. The evolution of human influenza viruses.

    PubMed Central

    Hay, A J; Gregory, V; Douglas, A R; Lin, Y P

    2001-01-01

    The evolution of influenza viruses results in (i) recurrent annual epidemics of disease that are caused by progressive antigenic drift of influenza A and B viruses due to the mutability of the RNA genome and (ii) infrequent but severe pandemics caused by the emergence of novel influenza A subtypes to which the population has little immunity. The latter characteristic is a consequence of the wide antigenic diversity and peculiar host range of influenza A viruses and the ability of their segmented RNA genomes to undergo frequent genetic reassortment (recombination) during mixed infections. Contrasting features of the evolution of recently circulating influenza AH1N1, AH3N2 and B viruses include the rapid drift of AH3N2 viruses as a single lineage, the slow replacement of successive antigenic variants of AH1N1 viruses and the co-circulation over some 25 years of antigenically and genetically distinct lineages of influenza B viruses. Constant monitoring of changes in the circulating viruses is important for maintaining the efficacy of influenza vaccines in combating disease. PMID:11779385

  20. Neutralization enzyme immunoassay for influenza virus.

    PubMed Central

    Benne, C A; Harmsen, M; De Jong, J C; Kraaijeveld, C A

    1994-01-01

    A neutralization enzyme immunoassay (N-EIA) was developed for the detection of antibody titer rises in sera of patients infected with influenza A (H3N2) virus. In this N-EIA, a selected strain of influenza A (H3N2) virus was added to monolayers of LLC-MK2 cells in microtiter plates. After 24 h, the replicated virus could be demonstrated with a virus-specific enzyme-labeled monoclonal antibody. Preincubation of the influenza virus with convalescent-phase sera of patients infected with influenza A (H3N2) virus resulted 1 day later in decreased absorbance values that could be used for calculation of neutralization titers. From use of paired serum samples from 10 patients with a history of flu-like symptoms, the results obtained with N-EIA correlated well (r = 0.83) with those of the standard hemagglutination inhibition test. PMID:8027355

  1. Analysis of in vivo dynamics of influenza virus infection in mice using a GFP reporter virus

    PubMed Central

    Manicassamy, Balaji; Manicassamy, Santhakumar; Belicha-Villanueva, Alan; Pisanelli, Giuseppe; Pulendran, Bali; García-Sastre, Adolfo

    2010-01-01

    Influenza A virus is being extensively studied because of its major impact on human and animal health. However, the dynamics of influenza virus infection and the cell types infected in vivo are poorly understood. These characteristics are challenging to determine, partly because there is no efficient replication-competent virus expressing an easily traceable reporter gene. Here, we report the generation of a recombinant influenza virus carrying a GFP reporter gene in the NS segment (NS1-GFP virus). Although attenuated when compared with wild-type virus, the NS1-GFP virus replicates efficiently in murine lungs and shows pathogenicity in mice. Using whole-organ imaging and flow cytometry, we have tracked the dynamics of influenza virus infection progression in mice. Imaging of murine lungs shows that infection starts in the respiratory tract in areas close to large conducting airways and later spreads to deeper sections of the lungs. In addition to epithelial cells, we found GFP-positive antigen-presenting cells, such as CD11b+CD11c−, CD11b−CD11c+, and CD11b+CD11c+, as early as 24 h after intranasal infection. In addition, a significant proportion of NK and B cells were GFP positive, suggesting active infection of these cells. We next tested the effects of the influenza virus inhibitors oseltamivir and amantadine on the kinetics of in vivo infection progression. Treatment with oseltamivir dramatically reduced influenza infection in all cell types, whereas, surprisingly, amantadine treatment more efficiently blocked infection in B and NK cells. Our results demonstrate high levels of immune cells harboring influenza virus antigen during viral infection and cell-type–specific effects upon treatment with antiviral agents, opening additional avenues of research in the influenza virus field. PMID:20534532

  2. Chitosan nanoparticle encapsulated hemagglutinin-split influenza virus mucosal vaccine.

    PubMed

    Sawaengsak, Chompoonuch; Mori, Yasuko; Yamanishi, Koichi; Mitrevej, Ampol; Sinchaipanid, Nuttanan

    2014-04-01

    Subunit/split influenza vaccines are less reactogenic compared with the whole virus vaccines. However, their immunogenicity is relatively low and thus required proper adjuvant and/or delivery vehicle for immunogenicity enhancement. Influenza vaccines administered intramuscularly induce minimum, if any, mucosal immunity at the respiratory mucosa which is the prime site of the infection. In this study, chitosan (CS) nanoparticles were prepared by ionic cross-linking of the CS with sodium tripolyphosphate (TPP) at the CS/TPP ratio of 1:0.6 using 2 h mixing time. The CS/TPP nanoparticles were used as delivery vehicle of an intranasal influenza vaccine made of hemagglutinin (HA)-split influenza virus product. Innocuousness, immunogenicity, and protective efficacy of the CS/TPP-HA vaccine were tested in influenza mouse model in comparison with the antigen alone vaccine. The CS/TPP-HA nanoparticles had required characteristics including nano-sizes, positive charges, and high antigen encapsulation efficiency. Mice that received two doses of the CS/TPP-HA vaccine intranasally showed no adverse symptoms indicating the vaccine innocuousness. The animals developed higher systemic and mucosal antibody responses than vaccine made of the HA-split influenza virus alone. The CS/TPP-HA vaccine could induce also a cell-mediated immune response shown as high numbers of IFN-γ-secreting cells in spleens while the HA vaccine alone could not. Besides, the CS nanoparticle encapsulated HA-split vaccine reduced markedly the influenza morbidity and also conferred 100% protective rate to the vaccinated mice against lethal influenza virus challenge. Overall results indicated that the CS nanoparticles invented in this study is an effective and safe delivery vehicle/adjuvant for the influenza vaccine. PMID:24343789

  3. Keeping the memory of influenza viruses.

    PubMed

    Combadière, B; Sibéril, S; Duffy, D

    2010-04-01

    Protection against pathogens is mediated by both humoral responses (neutralizing antibodies) and cellular immunity, both CD4+ and CD8+ cells. In the case of influenza viruses, circulating strains contain both variable and conserved T and B cell epitopes that are challenged after vaccination and/or infection. During infection, the role of T cells is to prevent viral dissemination in the organism by killing the infected cells and helping B cell antibody production to neutralize the virus. The threat of influenza virus increases the preparedness of protective immunity to pandemic and seasonal infection by vaccination. Several questions remain that need to be further addressed for the future development of innovative and rapidly efficient vaccines strategies. Firstly, what are the correlates of long-term protection (antibodies and/or T cells) against variant strains of influenza? How does the individual factors (age, natural immunity, vaccination and/or infection history) influence the generation and maintenance of memory cells? What are the factors allowing the maintenance of immune memory (regular contact with the pathogen or re-vaccination)? Secondly, what is the nature and quality (function / phenotype / location) of memory B and T cells? Finally, is it necessary to induce and maintain immunological memory against conserved proteins and/or to re-vaccinate against viral variants? What would be the consequences of repeated vaccination? These questions remain a subject of debate that will be further discussed. Since immunological memory is the cornerstone of vaccination, it is essential that we have a better understanding of its generation and maintenance over time as well as its contribution to recall responses during pandemics or after vaccination. PMID:20303671

  4. Immune responses elicited to a live-attenuated influenza virus vaccine compared to a traditional whole-inactivated virus vaccine for pandemic H1N1in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the United States there are currently two influenza vaccine platforms approved for use in humans - conventional inactivated virus and live-attenuated influenza virus (LAIV). One of the major challenges for influenza vaccination is designing a platform that provides cross-protection across strains...

  5. Immune mechanisms associated with enhanced influenza A virus disease versus cross-protection in vaccinated pigs.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccine associated enhanced respiratory disease (VAERD) has been described in pigs vaccinated with whole-inactivated influenza virus (WIV) following infection with heterologous influenza A virus (IAV). WIV vaccination elicits production of cross-reactive, non-neutralizing antibody to the challenge I...

  6. Biology and transmission of avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The natural host and reservoir for avian influenza is in wild birds where the viral infection is typically asymptomatic. The virus primarily replicates in the enteric tract and transmission is thought to be primarily by fecal-oral transmission. Avian influenza can infect a broad host range, but fo...

  7. A brief introduction to avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) causes a disease of high economic importance for poultry production worldwide. The earliest recorded cases of probable high pathogenicity AIV in poultry were reported in Italy in the 1870’s and avian influenza been recognized in domestic poultry through the modern era of ...

  8. Influenza A Viruses of Human Origin in Swine, Brazil.

    PubMed

    Nelson, Martha I; Schaefer, Rejane; Gava, Danielle; Cantão, Maurício Egídio; Ciacci-Zanella, Janice Reis

    2015-08-01

    The evolutionary origins of the influenza A(H1N1)pdm09 virus that caused the first outbreak of the 2009 pandemic in Mexico remain unclear, highlighting the lack of swine surveillance in Latin American countries. Although Brazil has one of the largest swine populations in the world, influenza was not thought to be endemic in Brazil's swine until the major outbreaks of influenza A(H1N1)pdm09 in 2009. Through phylogenetic analysis of whole-genome sequences of influenza viruses of the H1N1, H1N2, and H3N2 subtypes collected in swine in Brazil during 2009-2012, we identified multiple previously uncharacterized influenza viruses of human seasonal H1N2 and H3N2 virus origin that have circulated undetected in swine for more than a decade. Viral diversity has further increased in Brazil through reassortment between co-circulating viruses, including A(H1N1)pdm09. The circulation of multiple divergent hemagglutinin lineages challenges the design of effective cross-protective vaccines and highlights the need for additional surveillance. PMID:26196759

  9. Influenza A Viruses of Human Origin in Swine, Brazil

    PubMed Central

    Schaefer, Rejane; Gava, Danielle; Cantão, Maurício Egídio; Ciacci-Zanella, Janice Reis

    2015-01-01

    The evolutionary origins of the influenza A(H1N1)pdm09 virus that caused the first outbreak of the 2009 pandemic in Mexico remain unclear, highlighting the lack of swine surveillance in Latin American countries. Although Brazil has one of the largest swine populations in the world, influenza was not thought to be endemic in Brazil’s swine until the major outbreaks of influenza A(H1N1)pdm09 in 2009. Through phylogenetic analysis of whole-genome sequences of influenza viruses of the H1N1, H1N2, and H3N2 subtypes collected in swine in Brazil during 2009–2012, we identified multiple previously uncharacterized influenza viruses of human seasonal H1N2 and H3N2 virus origin that have circulated undetected in swine for more than a decade. Viral diversity has further increased in Brazil through reassortment between co-circulating viruses, including A(H1N1)pdm09. The circulation of multiple divergent hemagglutinin lineages challenges the design of effective cross-protective vaccines and highlights the need for additional surveillance. PMID:26196759

  10. Environmental role in influenza virus outbreaks.

    PubMed

    Sooryanarain, Harini; Elankumaran, Subbiah

    2015-01-01

    The environmental drivers of influenza outbreaks are largely unknown. Despite more than 50 years of research, there are conflicting lines of evidence on the role of the environment in influenza A virus (IAV) survival, stability, and transmissibility. With the increasing and looming threat of pandemic influenza, it is important to understand these factors for early intervention and long-term control strategies. The factors that dictate the severity and spread of influenza would include the virus, natural and acquired hosts, virus-host interactions, environmental persistence, virus stability and transmissibility, and anthropogenic interventions. Virus persistence in different environments is subject to minor variations in temperature, humidity, pH, salinity, air pollution, and solar radiations. Seasonality of influenza is largely dictated by temperature and humidity, with cool-dry conditions enhancing IAV survival and transmissibility in temperate climates in high latitudes, whereas humid-rainy conditions favor outbreaks in low latitudes, as seen in tropical and subtropical zones. In mid-latitudes, semiannual outbreaks result from alternating cool-dry and humid-rainy conditions. The mechanism of virus survival in the cool-dry or humid-rainy conditions is largely determined by the presence of salts and proteins in the respiratory droplets. Social determinants of heath, including health equity, vaccine acceptance, and age-related illness, may play a role in influenza occurrence and spread. PMID:25422855

  11. Expression of H5 hemagglutinin vaccine antigen in common duckweed (Lemna minor) protects against H5N1 high pathogenicity avian influenza virus challenge in immunized chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A synthetic hemagglutinin (HA) gene from the highly pathogenic avian influenza (HPAI) virus A/chicken/Indonesia/7/2003 (H5N1) (Indo/03) was expressed in aquatic plant Lemna minor (rLemna-HA). In Experiment 1, efficacy of rLemna-HA was tested on specific pathogen free (SPF) birds immunized with 0.2 ...

  12. Protection of chickens to antigenically variant avian influenza virus challenge after immunization with two antigenically unrelated strains of the same subtype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The antigenic diversity of avian influenza virus (AIV) within a subtype has been well established and is believed to be driven by the selection of immunologic escape mutants. In regions where vaccination against AIV has been implemented for prolonged periods (e.g. Vietnam and Egypt), vaccines which...

  13. Determination of efficacious vaccine seed strains for use against Egyptian H5N1 highly pathogenic avian influenza viruses through antigenic cartography and in vivo challenge studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2006, there have been reported outbreaks of H5N1 highly pathogenic avian influenza (HPAI) in vaccinated chickens in Africa and Asia. This study provides experimental data for selection of efficacious H5N1 vaccine seed strains against recently circulating strains of H5N1 HPAI viruses in Egypt....

  14. EFFICACY OF A FOWLPOX-VECTORED AVIAN INFLUENZA H5 VACCINE AGAINST ASIAN H5N1 HIGHLY PATHOGENIC AVIAN INFLUENZA VIRUS CHALLENGE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recombinant fowlpox-avian influenza (AI) H5 vaccine (rFP-AIV-H5) expressing the hemagglutinin of the A/turkey/Ireland/1378/83 H5N8 AI isolate has been used in Central America since 1998 to control H5N2 low pathogenicity (LP) AI. Previously, this vaccine was shown to induce full protection against...

  15. Innate immune evasion strategies of influenza viruses

    PubMed Central

    Hale, Benjamin G; Albrecht, Randy A; García-Sastre, Adolfo

    2010-01-01

    Influenza viruses are globally important human respiratory pathogens. These viruses cause seasonal epidemics and occasional worldwide pandemics, both of which can vary significantly in disease severity. The virulence of a particular influenza virus strain is partly determined by its success in circumventing the host immune response. This article briefly reviews the innate mechanisms that host cells have evolved to resist virus infection, and outlines the plethora of strategies that influenza viruses have developed in order to counteract such powerful defences. The molecular details of this virus–host interplay are summarized, and the ways in which research in this area is being applied to the rational design of protective vaccines and novel antivirals are discussed. PMID:20020828

  16. Efficacy of Influenza Vaccination and Tamiflu® Treatment – Comparative Studies with Eurasian Swine Influenza Viruses in Pigs

    PubMed Central

    Duerrwald, Ralf; Schlegel, Michael; Bauer, Katja; Vissiennon, Théophile; Wutzler, Peter; Schmidtke, Michaela

    2013-01-01

    Recent epidemiological developments demonstrated that gene segments of swine influenza A viruses can account for antigenic changes as well as reduced drug susceptibility of pandemic influenza A viruses. This raises questions about the efficacy of preventive measures against swine influenza A viruses. Here, the protective effect of vaccination was compared with that of prophylactic Tamiflu® treatment against two Eurasian swine influenza A viruses. 11-week-old pigs were infected by aerosol nebulisation with high doses of influenza virus A/swine/Potsdam/15/1981 (H1N1/1981, heterologous challenge to H1N1 vaccine strain) and A/swine/Bakum/1832/2000 (H1N2/2000, homologous challenge to H1N2 vaccine strain) in two independent trials. In each trial (i) 10 pigs were vaccinated twice with a trivalent vaccine (RESPIPORC® FLU3; 28 and 7 days before infection), (ii) another 10 pigs received 150 mg/day of Tamiflu® for 5 days starting 12 h before infection, and (iii) 12 virus-infected pigs were left unvaccinated and untreated and served as controls. Both viruses replicated efficiently in porcine respiratory organs causing influenza with fever, dyspnoea, and pneumonia. Tamiflu® treatment as well as vaccination prevented clinical signs and significantly reduced virus shedding. Whereas after homologous challenge with H1N2/2000 no infectious virus in lung and hardly any lung inflammation were detected, the virus titre was not and the lung pathology was only partially reduced in H1N1/1981, heterologous challenged pigs. Tamiflu® application did not affect these study parameters. In conclusion, all tested preventive measures provided protection against disease. Vaccination additionally prevented virus replication and histopathological changes in the lung of homologous challenged pigs. PMID:23630601

  17. Recent zoonoses caused by influenza A viruses.

    PubMed

    Alexander, D J; Brown, I H

    2000-04-01

    Influenza is a highly contagious, acute illness which has afflicted humans and animals since ancient times. Influenza viruses are part of the Orthomyxoviridae family and are grouped into types A, B and C according to antigenic characteristics of the core proteins. Influenza A viruses infect a large variety of animal species, including humans, pigs, horses, sea mammals and birds, occasionally producing devastating pandemics in humans, such as in 1918, when over twenty million deaths occurred world-wide. The two surface glycoproteins of the virus, haemagglutinin (HA) and neuraminidase (NA), are the most important antigens for inducing protective immunity in the host and therefore show the greatest variation. For influenza A viruses, fifteen antigenically distinct HA subtypes and nine NA subtypes are recognised at present; a virus possesses one HA and one NA subtype, apparently in any combination. Although viruses of relatively few subtype combinations have been isolated from mammalian species, all subtypes, in most combinations, have been isolated from birds. In the 20th Century, the sudden emergence of antigenically different strains in humans, termed antigenic shift, has occurred on four occasions, as follows, in 1918 (H1N1), 1957 (H2N2), 1968 (H3N2) and 1977 (H1N1), each resulting in a pandemic. Frequent epidemics have occurred between the pandemics as a result of gradual antigenic change in the prevalent virus, termed antigenic drift. Currently, epidemics occur throughout the world in the human population due to infection with influenza A viruses of subtypes H1N1 and H3N2 or with influenza B virus. The impact of these epidemics is most effectively measured by monitoring excess mortality due to pneumonia and influenza. Phylogenetic studies suggest that aquatic birds could be the source of all influenza A viruses in other species. Human pandemic strains are thought to have emerged through one of the following three mechanisms: genetic reassortment (occurring as a

  18. Epidemiological and Virological Characterization of Influenza B Virus Infections.

    PubMed

    Sharabi, Sivan; Drori, Yaron; Micheli, Michal; Friedman, Nehemya; Orzitzer, Sara; Bassal, Ravit; Glatman-Freedman, Aharona; Shohat, Tamar; Mendelson, Ella; Hindiyeh, Musa; Mandelboim, Michal

    2016-01-01

    While influenza A viruses comprise a heterogeneous group of clinically relevant influenza viruses, influenza B viruses form a more homogeneous cluster, divided mainly into two lineages: Victoria and Yamagata. This divergence has complicated seasonal influenza vaccine design, which traditionally contained two seasonal influenza A virus strains and one influenza B virus strain. We examined the distribution of the two influenza B virus lineages in Israel, between 2011-2014, in hospitalized and in non-hospitalized (community) influenza B virus-infected patients. We showed that influenza B virus infections can lead to hospitalization and demonstrated that during some winter seasons, both influenza B virus lineages circulated simultaneously in Israel. We further show that the influenza B virus Yamagata lineage was dominant, circulating in the county in the last few years of the study period, consistent with the anti-Yamagata influenza B virus antibodies detected in the serum samples of affected individuals residing in Israel in the year 2014. Interestingly, we found that elderly people were particularly vulnerable to Yamagata lineage influenza B virus infections. PMID:27533045

  19. Epidemiological and Virological Characterization of Influenza B Virus Infections

    PubMed Central

    Sharabi, Sivan; Drori, Yaron; Micheli, Michal; Friedman, Nehemya; Orzitzer, Sara; Bassal, Ravit; Glatman-Freedman, Aharona; Shohat, Tamar; Mendelson, Ella; Hindiyeh, Musa; Mandelboim, Michal

    2016-01-01

    While influenza A viruses comprise a heterogeneous group of clinically relevant influenza viruses, influenza B viruses form a more homogeneous cluster, divided mainly into two lineages: Victoria and Yamagata. This divergence has complicated seasonal influenza vaccine design, which traditionally contained two seasonal influenza A virus strains and one influenza B virus strain. We examined the distribution of the two influenza B virus lineages in Israel, between 2011–2014, in hospitalized and in non-hospitalized (community) influenza B virus-infected patients. We showed that influenza B virus infections can lead to hospitalization and demonstrated that during some winter seasons, both influenza B virus lineages circulated simultaneously in Israel. We further show that the influenza B virus Yamagata lineage was dominant, circulating in the county in the last few years of the study period, consistent with the anti-Yamagata influenza B virus antibodies detected in the serum samples of affected individuals residing in Israel in the year 2014. Interestingly, we found that elderly people were particularly vulnerable to Yamagata lineage influenza B virus infections. PMID:27533045

  20. Cross-Reactive, Cell-Mediated Immunity and Protection of Chickens from Lethal H5N1 Influenza Virus Infection in Hong Kong Poultry Markets

    PubMed Central

    Seo, Sang Heui; Webster, Robert G.

    2001-01-01

    In 1997, avian H5N1 influenza virus transmitted from chickens to humans resulted in 18 confirmed infections. Despite harboring lethal H5N1 influenza viruses, most chickens in the Hong Kong poultry markets showed no disease signs. At this time, H9N2 influenza viruses were cocirculating in the markets. We investigated the role of H9N2 influenza viruses in protecting chickens from lethal H5N1 influenza virus infections. Sera from chickens infected with an H9N2 influenza virus did not cross-react with an H5N1 influenza virus in neutralization or hemagglutination inhibition assays. Most chickens primed with an H9N2 influenza virus 3 to 70 days earlier survived the lethal challenge of an H5N1 influenza virus, but infected birds shed H5N1 influenza virus in their feces. Adoptive transfer of T lymphocytes or CD8+ T cells from inbred chickens (B2/B2) infected with an H9N2 influenza virus to naive inbred chickens (B2/B2) protected them from lethal H5N1 influenza virus. In vitro cytotoxicity assays showed that T lymphocytes or CD8+ T cells from chickens infected with an H9N2 influenza virus recognized target cells infected with either an H5N1 or H9N2 influenza virus in a dose-dependent manner. Our findings indicate that cross-reactive cellular immunity induced by H9N2 influenza viruses protected chickens from lethal infection with H5N1 influenza viruses in the Hong Kong markets in 1997 but permitted virus shedding in the feces. Our findings are the first to suggest that cross-reactive cellular immunity can change the outcome of avian influenza virus infection in birds in live markets and create a situation for the perpetuation of H5N1 influenza viruses. PMID:11222674

  1. Repeated Low-Dose Influenza Virus Infection Causes Severe Disease in Mice: a Model for Vaccine Evaluation

    PubMed Central

    Song, Yufeng; Wang, Xiang; Zhang, Hongbo; Tang, Xinying; Li, Min; Yao, Jufang; Jin, Xia; Ertl, Hildegund C. J.

    2015-01-01

    ABSTRACT Influenza infection causes severe disease and death in humans. In traditional vaccine research and development, a single high-dose virus challenge of animals is used to evaluate vaccine efficacy. This type of challenge model may have limitations. In the present study, we developed a novel challenge model by infecting mice repeatedly in short intervals with low doses of influenza A virus. Our results show that compared to a single high-dose infection, mice that received repeated low-dose challenges showed earlier morbidity and mortality and more severe disease. They developed higher vial loads, more severe lung pathology, and greater inflammatory responses and generated only limited influenza A virus-specific B and T cell responses. A commercial trivalent influenza vaccine protected mice against a single high and lethal dose of influenza A virus but was ineffective against repeated low-dose virus challenges. Overall, our data show that the repeated low-dose influenza A virus infection mouse model is more stringent and may thus be more suitable to select for highly efficacious influenza vaccines. IMPORTANCE Influenza epidemics and pandemics pose serious threats to public health. Animal models are crucial for evaluating the efficacy of influenza vaccines. Traditional models based on a single high-dose virus challenge may have limitations. Here, we describe a new mouse model based on repeated low-dose influenza A virus challenges given within a short period. Repeated low-dose challenges caused more severe disease in mice, associated with higher viral loads and increased lung inflammation and reduced influenza A virus-specific B and T cell responses. A commercial influenza vaccine that was shown to protect mice from high-dose challenge was ineffective against repeated low-dose challenges. Overall, our results show that the low-dose repeated-challenge model is more stringent and may therefore be better suited for preclinical vaccine efficacy studies. PMID

  2. Avian Influenza A (H7N9) Virus

    MedlinePlus

    ... this page: About CDC.gov . Avian Influenza H5 Viruses in the United States Updates and Publications Information ... Humans Examples of Human Infections with Avian Influenza Viruses Outbreaks Health Care and Laboratorian Guidance HPAI A ...

  3. Prevention and Treatment of Avian Influenza A Viruses in People

    MedlinePlus

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Button Past Newsletters Prevention and Treatment of Avian Influenza A Viruses in People Language: English Español ...

  4. Transmission of Avian Influenza A Viruses Between Animals and People

    MedlinePlus

    ... many different animals, including ducks, chickens, pigs, whales, horses, and seals. However, certain subtypes of influenza A ... pigs, and H7N7 and H3N8 virus infections of horses. Influenza A viruses that typically infect and transmit ...

  5. DIESEL EXHAUST ENHANCES INFLUENZA VIRUS INFECTIONS IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    Several factors, such as age and nutritional status can affect the susceptibility to influenza infections. Moreover, exposure to air pollutants, such as diesel exhaust (DE), has been shown to affect respiratory virus infections in rodent models. Influenza virus primarily infects ...

  6. [Influenza vaccination. Effectiveness of current vaccines and future challenges].

    PubMed

    Ortiz de Lejarazu, Raúl; Tamames, Sonia

    2015-01-01

    Seasonal influenza is an annual challenge for health-care systems, due to factors such as co-circulation of 2 influenza A subtypes jointly with 2 influenza B lineages; the antigenic drift of these virus, which eludes natural immunity, as well as immunity conferred by vaccination; together with influenza impact in terms of morbidity and mortality. Influenza vaccines have been available for more than 70 years and they have progressed in formulation, production and delivery route. Recommendations on vaccination are focused on those with a higher probability of severe disease, and have a progressively wider coverage, and classically based on inactivated vaccines, but with an increasing importance of attenuated live vaccines. More inactivated vaccines are becoming available, from adyuvanted and virosomal vaccines to intradermal delivery, cell-culture or quadrivalent. Overall vaccine effectiveness is about 65%, but varies depending on characteristics of vaccines, virus, population and the outcomes to be prevented, and ranges from less than 10% to almost 90%. Future challenges are formulations that confer more extensive and lasting protection, as well as increased vaccination coverage, especially in groups such as pregnant women and health-care professionals, as well as being extended to paediatrics. PMID:26232121

  7. Influenza Type A Viruses and Subtypes

    MedlinePlus

    ... virus infection of humans, such as with Asian-origin highly pathogenic avian influenza A (H5N1) viruses currently circulating among poultry in Asia and the Middle East have been reported in 16 countries, often resulting in severe pneumonia with approximately 60% ...

  8. Protection against multiple subtypes of influenza viruses by virus-like particle vaccines based on a hemagglutinin conserved epitope.

    PubMed

    Chen, Shaoheng; Zheng, Dan; Li, Changgui; Zhang, Wenjie; Xu, Wenting; Liu, Xueying; Fang, Fang; Chen, Ze

    2015-01-01

    We selected the conserved sequence in the stalk region of influenza virus hemagglutinin (HA) trimmer, the long alpha helix (LAH), as the vaccine candidate sequence, and inserted it into the major immunodominant region (MIR) of hepatitis B virus core protein (HBc), and, by using the E. coli expression system, we prepared a recombinant protein vaccine LAH-HBc in the form of virus-like particles (VLP). Intranasal immunization of mice with this LAH-HBc VLP plus cholera toxin B subunit with 0.2% of cholera toxin (CTB(*)) adjuvant could effectively elicit humoral and cellular immune responses and protect mice against a lethal challenge of homologous influenza viruses (A/Puerto Rico/8/1934 (PR8) (H1N1)). In addition, passage of the immune sera containing specific antibodies to naïve mice rendered them resistant against a lethal homologous challenge. Immunization with LAH-HBc VLP vaccine plus CTB(*) adjuvant could also fully protect mice against a lethal challenge of the 2009 pandemic H1N1 influenza virus or the avian H9N2 virus and could partially protect mice against a lethal challenge of the avian H5N1 influenza virus. This study demonstrated that the LAH-HBc VLP vaccine based on a conserved sequence of the HA trimmer stalk region is a promising candidate vaccine for developing a universal influenza vaccine against multiple influenza viruses infections. PMID:25767809

  9. Replication and transmission of influenza viruses in Japanese quail

    PubMed Central

    Makarova, Natalia V.; Ozaki, Hiroishi; Kida, Hiroshi; Webster, Robert G.; Perez, Daniel R.

    2015-01-01

    Quail have emerged as a potential intermediate host in the spread of avian influenza A viruses in poultry in Hong Kong. To better understand this possible role, we tested the replication and transmission in quail of influenza A viruses of all 15 HA subtypes. Quail supported the replication of at least 14 subtypes. Influenza A viruses replicated predominantly in the respiratory tract. Transmission experiments suggested that perpetuation of avian influenza viruses in quail requires adaptation. Swine influenza viruses were isolated from the respiratory tract of quail at low levels. There was no evidence of human influenza A or B virus replication. Interestingly, a human–avian recombinant containing the surface glycoprotein genes of a quail virus and the internal genes of a human virus replicated and transmitted readily in quail; therefore, quail could function as amplifiers of influenza virus reassortants that have the potential to infect humans and/or other mammalian species. PMID:12788625

  10. WOULD THE 1918 PANDEMIC INFLUENZA VIRUS BE A THREAT TODAY?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 1918 influenza pandemic caused more than 20 million deaths worldwide. Under biosafety level 3Ag containment, a recombinant influenza virus bearing the 1918 influenza virus hemagglutinin (HA) and neuraminidase (NA) was generated. This virus is highly virulent in mice, pointing to the 1918 HA and...

  11. Comparative pathology of select agent influenza A virus infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A virus infections may spread rapidly in human populations and cause acute respiratory disease with variable mortality. Two of these influenza viruses have been designated as select agents because of the high case fatality rate: 1918 H1N1 virus and highly pathogenic avian influenza (HPAI) ...

  12. Respiratory Viruses Other than Influenza Virus: Impact and Therapeutic Advances

    PubMed Central

    Nichols, W. Garrett; Peck Campbell, Angela J.; Boeckh, Michael

    2008-01-01

    Summary: Though several antivirals have been developed and marketed to treat influenza virus infections, the development of antiviral agents with clinical activity against other respiratory viruses has been more problematic. Here we review the epidemiology of respiratory viral infections in immunocompetent and immunocompromised hosts, examine the evidence surrounding the currently available antivirals for respiratory viral infections other than influenza, highlight those that are in the pipeline, and discuss the hurdles for development of such agents. PMID:18400797

  13. Broadly neutralizing antibodies against influenza viruses

    PubMed Central

    Laursen, Nick S.; Wilson, Ian A.

    2014-01-01

    Despite available antivirals and vaccines, influenza infections continue to be a major cause of mortality worldwide. Vaccination generally induces an effective, but strain-specific antibody response. As the virus continually evolves, new vaccines have to be administered almost annually when a novel strain becomes dominant. Furthermore, the sporadic emerging resistance to neuraminidase inhibitors among circulating strains suggests an urgent need for new therapeutic agents. Recently, several cross-reactive antibodies have been described, which neutralize an unprecedented spectrum of influenza viruses. These broadly neutralizing antibodies generally target conserved functional regions on the major influenza surface glycoprotein hemagglutinin (HA). The characterization of their neutralization breadth and epitopes on HA could stimulate the development of new antibody-based antivirals and broader influenza vaccines. PMID:23583287

  14. Antibody Titer Has Positive Predictive Value for Vaccine Protection against Challenge with Natural Antigenic-Drift Variants of H5N1 High-Pathogenicity Avian Influenza Viruses from Indonesia

    PubMed Central

    Suarez, David L.; Spackman, Erica; Jadhao, Samadhan; Dauphin, Gwenaelle; Kim-Torchetti, Mia; McGrane, James; Weaver, John; Daniels, Peter; Wong, Frank; Selleck, Paul; Wiyono, Agus; Indriani, Risa; Yupiana, Yuni; Sawitri Siregar, Elly; Prajitno, Teguh; Smith, Derek; Fouchier, Ron

    2015-01-01

    ABSTRACT Vaccines are used in integrated control strategies to protect poultry against H5N1 high-pathogenicity avian influenza (HPAI). H5N1 HPAI was first reported in Indonesia in 2003, and vaccination was initiated in 2004, but reports of vaccine failures began to emerge in mid-2005. This study investigated the role of Indonesian licensed vaccines, specific vaccine seed strains, and emerging variant field viruses as causes of vaccine failures. Eleven of 14 licensed vaccines contained the manufacturer's listed vaccine seed strains, but 3 vaccines contained a seed strain different from that listed on the label. Vaccines containing A/turkey/Wisconsin/1968 (WI/68), A/chicken/Mexico/28159-232/1994 (Mex/94), and A/turkey/England/N28/1973 seed strains had high serological potency in chickens (geometric mean hemagglutination inhibition [HI] titers, ≥1:169), but vaccines containing strain A/chicken/Guangdong/1/1996 generated by reverse genetics (rg; rgGD/96), A/chicken/Legok/2003 (Legok/03), A/chicken/Vietnam/C57/2004 generated by rg (rgVN/04), or A/chicken/Legok/2003 generated by rg (rgLegok/03) had lower serological potency (geometric mean HI titers, ≤1:95). In challenge studies, chickens immunized with any of the H5 avian influenza vaccines were protected against A/chicken/West Java/SMI-HAMD/2006 (SMI-HAMD/06) and were partially protected against A/chicken/Papua/TA5/2006 (Papua/06) but were not protected against A/chicken/West Java/PWT-WIJ/2006 (PWT/06). Experimental inactivated vaccines made with PWT/06 HPAI virus or rg-generated PWT/06 low-pathogenicity avian influenza (LPAI) virus seed strains protected chickens from lethal challenge, as did a combination of a commercially available live fowl poxvirus vaccine expressing the H5 influenza virus gene and inactivated Legok/03 vaccine. These studies indicate that antigenic variants did emerge in Indonesia following widespread H5 avian influenza vaccine usage, and efficacious inactivated vaccines can be developed using

  15. Influenza Virus Propagation in Embryonated Chicken Eggs

    PubMed Central

    Brauer, Rena; Chen, Peter

    2015-01-01

    Influenza infection is associated with about 36,000 deaths and more than 200,000 hospitalizations every year in the United States. The continuous emergence of new influenza virus strains due to mutation and re-assortment complicates the control of the virus and necessitates the permanent development of novel drugs and vaccines. The laboratory-based study of influenza requires a reliable and cost-effective method for the propagation of the virus. Here, a comprehensive protocol is provided for influenza A virus propagation in fertile chicken eggs, which consistently yields high titer viral stocks. In brief, serum pathogen-free (SPF) fertilized chicken eggs are incubated at 37 °C and 55-60% humidity for 10 – 11 days. Over this period, embryo development can be easily monitored using an egg candler. Virus inoculation is carried out by injection of virus stock into the allantoic cavity using a needle. After 2 days of incubation at 37 °C, the eggs are chilled for at least 4 hr at 4 °C. The eggshell above the air sac and the chorioallantoic membrane are then carefully opened, and the allantoic fluid containing the virus is harvested. The fluid is cleared from debris by centrifugation, aliquoted and transferred to -80 °C for long-term storage. The large amount (5-10 ml of virus-containing fluid per egg) and high virus titer which is usually achieved with this protocol has made the usage of eggs for virus preparation our favorable method, in particular for in vitro studies which require large quantities of virus in which high dosages of the same virus stock are needed. PMID:25867050

  16. Influenza virus propagation in embryonated chicken eggs.

    PubMed

    Brauer, Rena; Chen, Peter

    2015-01-01

    Influenza infection is associated with about 36,000 deaths and more than 200,000 hospitalizations every year in the United States. The continuous emergence of new influenza virus strains due to mutation and re-assortment complicates the control of the virus and necessitates the permanent development of novel drugs and vaccines. The laboratory-based study of influenza requires a reliable and cost-effective method for the propagation of the virus. Here, a comprehensive protocol is provided for influenza A virus propagation in fertile chicken eggs, which consistently yields high titer viral stocks. In brief, serum pathogen-free (SPF) fertilized chicken eggs are incubated at 37 °C and 55-60% humidity for 10-11 days. Over this period, embryo development can be easily monitored using an egg candler. Virus inoculation is carried out by injection of virus stock into the allantoic cavity using a needle. After 2 days of incubation at 37 °C, the eggs are chilled for at least 4 hr at 4 °C. The eggshell above the air sac and the chorioallantoic membrane are then carefully opened, and the allantoic fluid containing the virus is harvested. The fluid is cleared from debris by centrifugation, aliquoted and transferred to -80 °C for long-term storage. The large amount (5-10 ml of virus-containing fluid per egg) and high virus titer which is usually achieved with this protocol has made the usage of eggs for virus preparation our favorable method, in particular for in vitro studies which require large quantities of virus in which high dosages of the same virus stock are needed. PMID:25867050

  17. Pandemic and Seasonal Influenza: Therapeutic Challenges

    PubMed Central

    Memoli, Matthew J.; Morens, David M.; Taubenberger, Jeffery K.

    2008-01-01

    Influenza A viruses cause significant morbidity and mortality annually, and the threat of a pandemic underscores the need for new therapeutic strategies. Here we briefly discuss novel antiviral agents under investigation, the limitations of current antiviral therapy and stress the importance of secondary bacterial infections in seasonal and pandemic influenza. Additionally, the lack of new antibiotics available to treat increasingly drug resistant organisms such as methicillin-resistant Staphylococcus aureus, pneumococci, Acinetobacter, extended spectrum beta-lactamase producing gram negative bacteria and Clostridium difficile is highlighted as an important component of influenza treatment and pandemic preparedness. Addressing these problems will require a multidisciplinary approach, which includes the development of novel antivirals and new antibiotics, as well as a better understanding of the role secondary infections play on the morbidity and mortality due to influenza infection. PMID:18598914

  18. Protective effect of dietary xylitol on influenza A virus infection.

    PubMed

    Yin, Sun Young; Kim, Hyoung Jin; Kim, Hong-Jin

    2014-01-01

    Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide) and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases. PMID:24392148

  19. Protective Effect of Dietary Xylitol on Influenza A Virus Infection

    PubMed Central

    Yin, Sun Young; Kim, Hyoung Jin; Kim, Hong-Jin

    2014-01-01

    Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide) and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases. PMID:24392148

  20. Role of receptor binding specificity in influenza A virus transmission and pathogenesis

    PubMed Central

    de Graaf, Miranda; Fouchier, Ron A M

    2014-01-01

    The recent emergence of a novel avian A/H7N9 influenza virus in poultry and humans in China, as well as laboratory studies on adaptation and transmission of avian A/H5N1 influenza viruses, has shed new light on influenza virus adaptation to mammals. One of the biological traits required for animal influenza viruses to cross the species barrier that received considerable attention in animal model studies, in vitro assays, and structural analyses is receptor binding specificity. Sialylated glycans present on the apical surface of host cells can function as receptors for the influenza virus hemagglutinin (HA) protein. Avian and human influenza viruses typically have a different sialic acid (SA)-binding preference and only few amino acid changes in the HA protein can cause a switch from avian to human receptor specificity. Recent experiments using glycan arrays, virus histochemistry, animal models, and structural analyses of HA have added a wealth of knowledge on receptor binding specificity. Here, we review recent data on the interaction between influenza virus HA and SA receptors of the host, and the impact on virus host range, pathogenesis, and transmission. Remaining challenges and future research priorities are also discussed. PMID:24668228

  1. Efficacy of intranasal administration of a truncated NS1 modified live influenza virus vaccine in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the U.S., despite available swine influenza virus (SIV) vaccines, multiple influenza subtypes as well as antigenic and genetic variants within subtypes continue to circulate in the swine population. One of the challenges to control and eliminate SIV is that the currently used inactivated influenz...

  2. Ambient Influenza and Avian Influenza Virus during Dust Storm Days and Background Days

    PubMed Central

    Chen, Pei-Shih; Tsai, Feng Ta; Lin, Chien Kun; Yang, Chun-Yuh; Chan, Chang-Chuan; Young, Chea-Yuan; Lee, Chien-Hung

    2010-01-01

    Background The spread of influenza and highly pathogenic avian influenza (H5N1) presents a significant threat to human health. Avian influenza outbreaks in downwind areas of Asian dust storms (ADS) suggest that viruses might be transported by dust storms. Objectives We developed a technique to measure ambient influenza and avian influenza viruses. We then used this technique to measure concentrations of these viruses on ADS days and background days, and to assess the relationships between ambient influenza and avian influenza viruses, and air pollutants. Methods A high-volume air sampler was used in parallel with a filter cassette to evaluate spiked samples and unspiked samples. Then, air samples were monitored during ADS seasons using a filter cassette coupled with a real-time quantitative polymerase chain reaction (qPCR) assay. Air samples were monitored during ADS season (1 January to 31 May 2006). Results We successfully quantified ambient influenza virus using the filtration/real-time qPCR method during ADS days and background days. To our knowledge, this is the first report describing the concentration of influenza virus in ambient air. In both the spiked and unspiked samples, the concentration of influenza virus sampled using the filter cassette was higher than that using the high-volume sampler. The concentration of ambient influenza A virus was significantly higher during the ADS days than during the background days. Conclusions Our data imply the possibility of long-range transport of influenza virus. PMID:20435545

  3. CT findings in viral lower respiratory tract infections caused by parainfluenza virus, influenza virus and respiratory syncytial virus

    PubMed Central

    Kim, Min-Chul; Kim, Mi Young; Lee, Hyun Joo; Lee, Sang-Oh; Choi, Sang-Ho; Kim, Yang Soo; Woo, Jun Hee; Kim, Sung-Han

    2016-01-01

    Abstract Viral lower respiratory tract infections (LRTIs) can present with a variety of computed tomography (CT) findings. However, identifying the contribution of a particular virus to CT findings is challenging due to concomitant infections and the limited data on the CT findings in viral LRTIs. We therefore investigate the CT findings in different pure viral LRTIs. All patients who underwent bronchoalveolar lavage (BAL) and were diagnosed with LRTIs caused by parainfluenza virus (PIV), influenza virus, or respiratory syncytial virus (RSV) between 1998 and 2014 were enrolled in a tertiary hospital in Seoul, South Korea. A pure viral LRTI was defined as a positive viral culture from BAL without any positive evidence from respiratory or blood cultures, or from polymerase chain reaction (PCR), or from serologic tests for bacteria, fungi, mycobacteria, or other viruses. CT images of 40 patients with viral LRTIs were analyzed: 14 with PIV, 14 with influenza virus, and 12 with RSV. Patch consolidation (≥1 cm or more than 1 segmental level) was found only in PIV (29%) (P = 0.03), by which CT findings caused by PIV could resemble those seen in bacterial LRTIs. Ground-glass opacities were seen in all cases of influenza virus and were more frequent than in PIV (71%) and RSV (67%) (P = 0.05). Bronchial wall thickening was more common in influenza virus (71%) and RSV (67%) LRTIs than PIV LRTIs (21%) (P = 0.02). With respect to anatomical distribution, PIV infections generally affected the lower lobes (69%), while influenza virus mostly caused diffuse changes throughout the lungs (57%), and RSV frequently formed localized patterns in the upper and mid lobes (44%). The CT findings in LRTIs of PIV, influenza virus, and RSV can be distinguished by certain characteristics. These differences could be useful for early differentiation of these viral LRTIs, and empirical use of appropriate antiviral agents. PMID:27368011

  4. Influenza viruses in birds: rapid identification by counterimmunoelectrophoresis.

    PubMed Central

    Lecomte, J; Berthiaume, L; Boudreault, A

    1979-01-01

    Counterimmunoelectrophoresis with an antiserum raised in rabbits against the M protein of the avian N virus proved to be particularly useful for large-scale identification of influenza A virus isolates. Of a total of 231 hemagglutinating agents isolated from 1,656 rectal swabs collected from shore and open-country birds, 158 could be identified as influenza A viruses by counterimmunoelectrophoresis, and 75 were serologically related to Newcastle disease virus by hemagglutination inhibition with an antiserum to Newcastle disease virus. Two isolates contained a mixture of influenza A virus and Newcastle disease virus; although the Newcastle disease virus virus particles outnumbered the influenza A virus particles in a ratio of 1,000:1, as seen by electron microscopy, the latter could be readily detected by counterimmunoelectrophoresis. This type of assay appears to be of potential use for epidemiological surveillance of influenza virus isolated from humans and animals. It combines specificity, sensitivity, and simplicity. Images PMID:85632

  5. Influenza A virus infection in zebrafish recapitulates mammalian infection and sensitivity to anti-influenza drug treatment.

    PubMed

    Gabor, Kristin A; Goody, Michelle F; Mowel, Walter K; Breitbach, Meghan E; Gratacap, Remi L; Witten, P Eckhard; Kim, Carol H

    2014-11-01

    Seasonal influenza virus infections cause annual epidemics and sporadic pandemics. These present a global health concern, resulting in substantial morbidity, mortality and economic burdens. Prevention and treatment of influenza illness is difficult due to the high mutation rate of the virus, the emergence of new virus strains and increasing antiviral resistance. Animal models of influenza infection are crucial to our gaining a better understanding of the pathogenesis of and host response to influenza infection, and for screening antiviral compounds. However, the current animal models used for influenza research are not amenable to visualization of host-pathogen interactions or high-throughput drug screening. The zebrafish is widely recognized as a valuable model system for infectious disease research and therapeutic drug testing. Here, we describe a zebrafish model for human influenza A virus (IAV) infection and show that zebrafish embryos are susceptible to challenge with both influenza A strains APR8 and X-31 (Aichi). Influenza-infected zebrafish show an increase in viral burden and mortality over time. The expression of innate antiviral genes, the gross pathology and the histopathology in infected zebrafish recapitulate clinical symptoms of influenza infections in humans. This is the first time that zebrafish embryos have been infected with a fluorescent IAV in order to visualize infection in a live vertebrate host, revealing a pattern of vascular endothelial infection. Treatment of infected zebrafish with a known anti-influenza compound, Zanamivir, reduced mortality and the expression of a fluorescent viral gene product, demonstrating the validity of this model to screen for potential antiviral drugs. The zebrafish model system has provided invaluable insights into host-pathogen interactions for a range of infectious diseases. Here, we demonstrate a novel use of this species for IAV research. This model has great potential to advance our understanding of

  6. Influenza A Virus Attenuation by Codon Deoptimization of the NS Gene for Vaccine Development

    PubMed Central

    Nogales, Aitor; Baker, Steven F.; Ortiz-Riaño, Emilio; Dewhurst, Stephen; Topham, David J.

    2014-01-01

    ABSTRACT Influenza viral infection represents a serious public health problem that causes contagious respiratory disease, which is most effectively prevented through vaccination to reduce transmission and future infection. The nonstructural (NS) gene of influenza A virus encodes an mRNA transcript that is alternatively spliced to express two viral proteins, the nonstructural protein 1 (NS1) and the nuclear export protein (NEP). The importance of the NS gene of influenza A virus for viral replication and virulence has been well described and represents an attractive target to generate live attenuated influenza viruses with vaccine potential. Considering that most amino acids can be synthesized from several synonymous codons, this study employed the use of misrepresented mammalian codons (codon deoptimization) for the de novo synthesis of a viral NS RNA segment based on influenza A/Puerto Rico/8/1934 (H1N1) (PR8) virus. We generated three different recombinant influenza PR8 viruses containing codon-deoptimized synonymous mutations in coding regions comprising the entire NS gene or the mRNA corresponding to the individual viral protein NS1 or NEP, without modifying the respective splicing and packaging signals of the viral segment. The fitness of these synthetic viruses was attenuated in vivo, while they retained immunogenicity, conferring both homologous and heterologous protection against influenza A virus challenges. These results indicate that influenza viruses can be effectively attenuated by synonymous codon deoptimization of the NS gene and open the possibility of their use as a safe vaccine to prevent infections with these important human pathogens. IMPORTANCE Vaccination serves as the best therapeutic option to protect humans against influenza viral infections. However, the efficacy of current influenza vaccines is suboptimal, and novel approaches are necessary for the prevention of disease cause by this important human respiratory pathogen. The nonstructural

  7. Interval Between Infections and Viral Hierarchy Are Determinants of Viral Interference Following Influenza Virus Infection in a Ferret Model

    PubMed Central

    Laurie, Karen L.; Guarnaccia, Teagan A.; Carolan, Louise A.; Yan, Ada W. C.; Aban, Malet; Petrie, Stephen; Cao, Pengxing; Heffernan, Jane M.; McVernon, Jodie; Mosse, Jennifer; Kelso, Anne; McCaw, James M.; Barr, Ian G.

    2015-01-01

    Background. Epidemiological studies suggest that, following infection with influenza virus, there is a short period during which a host experiences a lower susceptibility to infection with other influenza viruses. This viral interference appears to be independent of any antigenic similarities between the viruses. We used the ferret model of human influenza to systematically investigate viral interference. Methods. Ferrets were first infected then challenged 1–14 days later with pairs of influenza A(H1N1)pdm09, influenza A(H3N2), and influenza B viruses circulating in 2009 and 2010. Results. Viral interference was observed when the interval between initiation of primary infection and subsequent challenge was <1 week. This effect was virus specific and occurred between antigenically related and unrelated viruses. Coinfections occurred when 1 or 3 days separated infections. Ongoing shedding from the primary virus infection was associated with viral interference after the secondary challenge. Conclusions. The interval between infections and the sequential combination of viruses were important determinants of viral interference. The influenza viruses in this study appear to have an ordered hierarchy according to their ability to block or delay infection, which may contribute to the dominance of different viruses often seen in an influenza season. PMID:25943206

  8. Swine as a model for influenza A virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A viruses (IAV) infect a variety of hosts, including humans, swine, and various avian species. The annual influenza disease burden in the human population remains significant even with current vaccine usage and much about the pathogenesis and transmission of influenza viruses in human rema...

  9. KINETIC PROFILE OF INFLUENZA VIRUS INFECTION IN THREE RAT STRAINS

    EPA Science Inventory

    Abstract

    Influenza infection is a respiratory disease of viral origin that can cause major epidemics in man. The influenza virus infects and damages epithelial cells of the respiratory tract and causes pneumonia. Lung lesions of mice infected with influenza virus resembl...

  10. THE MOLECULAR BIOLOGY OF AVIAN INFLUENZA VIRUS IN SHORT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is an important pathogen of poultry as it can cause severe economic losses through disease, including respiratory signs and mortality, and effects on trade. Avian influenza virus is classified as type A influenza, which is a member of the orthomyxoviridae family. Charact...

  11. Interaction of nanodiamonds materials with influenza viruses

    NASA Astrophysics Data System (ADS)

    Ivanova, V. T.; Ivanova, M. V.; Spitsyn, B. V.; Garina, K. O.; Trushakova, S. V.; Manykin, A. A.; Korzhenevsky, A. P.; Burseva, E. I.

    2012-02-01

    The perspectives of the application of modern materials contained nanodiamonds (ND) are considered in this study. The interaction between detonation paniculate ND, soot and influenza A and B viruses, fragments of cDNA were analyzed at the normal conditions. It was shown that these sorbents can interact with the following viruses: reference epidemic strains of influenza A(H1N1), A(H1N1)v, A(H3N2) and B viruses circulated in the word in 2000-2010. The allantoises, concentrated viruses, cDNA can be absorbed by ND sorbents and getting removed from water solutions within 20 min. ND sorbents can be used for the preparation of antivirus filters for water solution and for future diagnostic systems in virology.

  12. Protective immunity and safety of a genetically modified influenza virus vaccine.

    PubMed

    Barbosa, Rafael Polidoro Alves; Salgado, Ana Paula Carneiro; Garcia, Cristiana Couto; Filho, Bruno Galvão; Gonçalves, Ana Paula de Faria; Lima, Braulio Henrique Freire; Lopes, Gabriel Augusto Oliveira; Rachid, Milene Alvarenga; Peixoto, Andiara Cristina Cardoso; de Oliveira, Danilo Bretas; Ataíde, Marco Antônio; Zirke, Carla Aparecida; Cotrim, Tatiane Marques; Costa, Érica Azevedo; Almeida, Gabriel Magno de Freitas; Russo, Remo Castro; Gazzinelli, Ricardo Tostes; Machado, Alexandre de Magalhães Vieira

    2014-01-01

    Recombinant influenza viruses are promising viral platforms to be used as antigen delivery vectors. To this aim, one of the most promising approaches consists of generating recombinant viruses harboring partially truncated neuraminidase (NA) segments. To date, all studies have pointed to safety and usefulness of this viral platform. However, some aspects of the inflammatory and immune responses triggered by those recombinant viruses and their safety to immunocompromised hosts remained to be elucidated. In the present study, we generated a recombinant influenza virus harboring a truncated NA segment (vNA-Δ) and evaluated the innate and inflammatory responses and the safety of this recombinant virus in wild type or knock-out (KO) mice with impaired innate (Myd88 -/-) or acquired (RAG -/-) immune responses. Infection using truncated neuraminidase influenza virus was harmless regarding lung and systemic inflammatory response in wild type mice and was highly attenuated in KO mice. We also demonstrated that vNA-Δ infection does not induce unbalanced cytokine production that strongly contributes to lung damage in infected mice. In addition, the recombinant influenza virus was able to trigger both local and systemic virus-specific humoral and CD8+ T cellular immune responses which protected immunized mice against the challenge with a lethal dose of homologous A/PR8/34 influenza virus. Taken together, our findings suggest and reinforce the safety of using NA deleted influenza viruses as antigen delivery vectors against human or veterinary pathogens. PMID:24927156

  13. Continuous Influenza Virus Production in Cell Culture Shows a Periodic Accumulation of Defective Interfering Particles

    PubMed Central

    Pflugmacher, Antje; Behrendt, Ilona; Jordan, Ingo; Flockerzi, Dietrich; Genzel, Yvonne; Reichl, Udo

    2013-01-01

    Influenza viruses are a major public health burden during seasonal epidemics and a continuous threat due to their potential to cause pandemics. Annual vaccination provides the best protection against the contagious respiratory illness caused by influenza viruses. However, the current production capacities for influenza vaccines are insufficient to meet the increasing demands. We explored the possibility to establish a continuous production process for influenza viruses using the duck-derived suspension cell line AGE1.CR. A two-stage bioreactor setup was designed in which cells were cultivated in a first stirred tank reactor where an almost constant cell concentration was maintained. Cells were then constantly fed to a second bioreactor where virus infection and replication took place. Using this two-stage reactor system, it was possible to continuously produce influenza viruses. Surprisingly, virus titers showed a periodic increase and decrease during the run-time of 17 days. These titer fluctuations were caused by the presence of defective interfering particles (DIPs), which we detected by PCR. Mathematical modeling confirmed this observation showing that constant virus titers can only emerge in the absence of DIPs. Even with very low amounts of DIPs in the seed virus and very low rates for de novo DIP generation, defective viruses rapidly accumulate and, therefore, represent a serious challenge for continuous vaccine production. Yet, the continuous replication of influenza virus using a two-stage bioreactor setup is a novel tool to study aspects of viral evolution and the impact of DIPs. PMID:24039749

  14. Protective effects of phillyrin against influenza A virus in vivo.

    PubMed

    Qu, Xin-Yan; Li, Qing-Jun; Zhang, Hui-Min; Zhang, Xiao-Juan; Shi, Peng-Hui; Zhang, Xiu-Juan; Yang, Jing; Zhou, Zhe; Wang, Sheng-Qi

    2016-07-01

    Influenza A virus infection represents a great threat to public health. However, owing to side effects and the emergence of resistant virus strains, the use of currently available anti-influenza drugs may be limited. In order to identify novel anti-influenza drugs, we investigated the antiviral effects of phillyrin against influenza A virus infection in vivo. The mean survival time, lung index, viral titers, influenza hemagglutinin (HA) protein and serum cytokines levels, and histopathological changes in lung tissue were examined. Administration of phillyrin at a dose of 20 mg/kg/day for 3 days significantly prolonged the mean survival time, reduced the lung index, decreased the virus titers and interleukin-6 levels, reduced the expression of HA, and attenuated lung tissue damage in mice infected with influenza A virus. Taken together, these data showed that phillyrin had potential protective effects against infection caused by influenza A virus. PMID:27323762

  15. Cyclophilin A protects mice against infection by influenza A virus

    PubMed Central

    Li, Jing; Chen, Can; Wong, Gary; Dong, Wei; Zheng, Weinan; Li, Yun; Sun, Lei; Zhang, Lianfeng; Gao, George F.; Bi, Yuhai; Liu, Wenjun

    2016-01-01

    Our previous studies indicate that Cyclophilin A (CypA) impairs the replication of influenza A virus in vitro. To further evaluate the antiviral functions of CypA and explore its mechanism, transgenic mice with overexpression of CypA by two specific promoters with SPC (CypA-SPC) or CMV (CypA-CMV) were developed. After challenge with the A/WSN/33(H1N1) influenza virus, CypA-SPC and CypA-CMV transgenic mice displayed nearly 2.5- and 3.8-fold stronger disease resistance to virus infection, respectively, compared to wild-type animals. Virus replication, pathological lesions and inflammatory cytokines were substantially reduced in both lines of transgenic mice. In addition, after infection there was an upregulation of genes associated with cell migration, immune function, and organ development; and a downregulation of genes associated with the positive regulation of immune cells and apoptosis in the peritoneal macrophages of CypA-overexpressing transgenic mice (CypA+). These results indicate that CypA is a key modulator of influenza virus resistance in mice, and that CypA+ mice constitutes an important model to study the roles of CypA in the regulation of immune responses and infections. PMID:27354005

  16. Cyclophilin A protects mice against infection by influenza A virus.

    PubMed

    Li, Jing; Chen, Can; Wong, Gary; Dong, Wei; Zheng, Weinan; Li, Yun; Sun, Lei; Zhang, Lianfeng; Gao, George F; Bi, Yuhai; Liu, Wenjun

    2016-01-01

    Our previous studies indicate that Cyclophilin A (CypA) impairs the replication of influenza A virus in vitro. To further evaluate the antiviral functions of CypA and explore its mechanism, transgenic mice with overexpression of CypA by two specific promoters with SPC (CypA-SPC) or CMV (CypA-CMV) were developed. After challenge with the A/WSN/33(H1N1) influenza virus, CypA-SPC and CypA-CMV transgenic mice displayed nearly 2.5- and 3.8-fold stronger disease resistance to virus infection, respectively, compared to wild-type animals. Virus replication, pathological lesions and inflammatory cytokines were substantially reduced in both lines of transgenic mice. In addition, after infection there was an upregulation of genes associated with cell migration, immune function, and organ development; and a downregulation of genes associated with the positive regulation of immune cells and apoptosis in the peritoneal macrophages of CypA-overexpressing transgenic mice (CypA+). These results indicate that CypA is a key modulator of influenza virus resistance in mice, and that CypA+ mice constitutes an important model to study the roles of CypA in the regulation of immune responses and infections. PMID:27354005

  17. The changing face of swine influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    "Flu" in pigs has been known for 90 years and on the surface it may appear as though little has changed. We still suspect flu when a high percentage of pigs have a sudden onset of barking cough, especially during temperature fluctuations in the fall or spring. However, the influenza viruses responsi...

  18. VIRUS VACCINE RESEARCH AT THE NATIONAL ANIMAL DISEASE CENTER: LESSONS FROM SWINE INFLUENZA VIRUS AND BOVINE VIRAL DIARRHEA VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The continuing emergence of novel subtypes and genetic variants of swine influenza viruses (SIV) causing swine flu challenges our ability to effectively manage this high morbidity disease among swine. New strategic approaches for vaccine development must be considered to keep up with the ever-evolv...

  19. Promoter analysis of influenza virus RNA polymerase.

    PubMed Central

    Parvin, J D; Palese, P; Honda, A; Ishihama, A; Krystal, M

    1989-01-01

    Influenza virus polymerase, which was prepared depleted of viral RNA, was used to copy small RNA templates prepared from plasmid-encoded sequences. Template constructions containing only the 3' end of genomic RNA were shown to be efficiently copied, indicating that the promoter lay solely within the 15-nucleotide 3' terminus. Sequences not specific for the influenza virus termini were not copied, and, surprisingly, RNAs containing termini identical to those from plus-sense cRNA were copied at low levels. The specificity for recognition of the virus sense promoter was further defined by site-specific mutagenesis. It was also found that increased levels of viral protein were required in order to catalyze both the cap endonuclease-primed and primer-free RNA synthesis from these model templates, as well as from genomic-length RNAs. This finding indicates that the reconstituted system has catalytic properties very similar to those of native viral ribonucleoprotein complexes. Images PMID:2585601

  20. Enhanced Pneumonia and Proinflammatory Cytokine Response in Pigs Challenged with Pandemic 2009 A/H1N1 Influenza Virus Following Vaccination with an Inactivated delta-Cluster H1N2 Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endemic strains of swine influenza A virus (IAV) in North America consist of the subtypes H1N1, H1N2, and H3N2. These circulating strains contain the triple reassortant internal gene (TRIG) cassette resulting from incorporation of genes from swine, avian, and human IAV’s. Genetic drift and reassortm...

  1. Potent Neutralization of Influenza A Virus by a Single-Domain Antibody Blocking M2 Ion Channel Protein

    PubMed Central

    Wei, Guowei; Meng, Weixu; Guo, Haijiang; Pan, Weiqi; Liu, Jinsong; Peng, Tao; Chen, Ling; Chen, Chang-You

    2011-01-01

    Influenza A virus poses serious health threat to humans. Neutralizing antibodies against the highly conserved M2 ion channel is thought to offer broad protection against influenza A viruses. Here, we screened synthetic Camel single-domain antibody (VHH) libraries against native M2 ion channel protein. One of the isolated VHHs, M2-7A, specifically bound to M2-expressed cell membrane as well as influenza A virion, inhibited replication of both amantadine-sensitive and resistant influenza A viruses in vitro, and protected mice from a lethal influenza virus challenge. Moreover, M2-7A showed blocking activity for proton influx through M2 ion channel. These pieces of evidence collectively demonstrate for the first time that a neutralizing antibody against M2 with broad specificity is achievable, and M2-7A may have potential for cross protection against a number of variants and subtypes of influenza A viruses. PMID:22164266

  2. Influenza Virus Evolution, Host Adaptation and Pandemic Formation

    PubMed Central

    Taubenberger, Jeffery K.; Kash, John C.

    2010-01-01

    Newly emerging or `re-emerging' viral diseases continue to pose significant global public health threats. Prototypic are influenza viruses that are major causes of human respiratory infections and mortality. Influenza viruses can cause zoonotic infections and adapt to humans leading to sustained transmission and emergence of novel viruses. Mechanisms by which viruses evolve in one host, cause zoonotic infection and adapt to a new host species remain unelucidated. Here we review evolution of influenza A viruses in their reservoir hosts and discuss genetic changes associated with introduction of novel viruses into humans leading to pandemics and the establishment of seasonal viruses. PMID:20542248

  3. Swine influenza virus: zoonotic potential and vaccination strategies for the control of avian and swine influenzas.

    PubMed

    Thacker, Eileen; Janke, Bruce

    2008-02-15

    Influenza viruses are able to infect humans, swine, and avian species, and swine have long been considered a potential source of new influenza viruses that can infect humans. Swine have receptors to which both avian and mammalian influenza viruses bind, which increases the potential for viruses to exchange genetic sequences and produce new reassortant viruses in swine. A number of genetically diverse viruses are circulating in swine herds throughout the world and are a major cause of concern to the swine industry. Control of swine influenza is primarily through the vaccination of sows, to protect young pigs through maternally derived antibodies. However, influenza viruses continue to circulate in pigs after the decay of maternal antibodies, providing a continuing source of virus on a herd basis. Measures to control avian influenza in commercial poultry operations are dictated by the virulence of the virus. Detection of a highly pathogenic avian influenza (HPAI) virus results in immediate elimination of the flock. Low-pathogenic avian influenza viruses are controlled through vaccination, which is done primarily in turkey flocks. Maintenance of the current HPAI virus-free status of poultry in the United States is through constant surveillance of poultry flocks. Although current influenza vaccines for poultry and swine are inactivated and adjuvanted, ongoing research into the development of newer vaccines, such as DNA, live-virus, or vectored vaccines, is being done. Control of influenza virus infection in poultry and swine is critical to the reduction of potential cross-species adaptation and spread of influenza viruses, which will minimize the risk of animals being the source of the next pandemic. PMID:18269323

  4. Transmission of Influenza B Viruses in the Guinea Pig

    PubMed Central

    Pica, Natalie; Chou, Yi-Ying; Bouvier, Nicole M.

    2012-01-01

    Epidemic influenza is typically caused by infection with viruses of the A and B types and can result in substantial morbidity and mortality during a given season. Here we demonstrate that influenza B viruses can replicate in the upper respiratory tract of the guinea pig and that viruses of the two main lineages can be transmitted with 100% efficiency between inoculated and naïve animals in both contact and noncontact models. Our results also indicate that, like in the case for influenza A virus, transmission of influenza B viruses is enhanced at colder temperatures, providing an explanation for the seasonality of influenza epidemics in temperate climates. We therefore present, for the first time, a small animal model with which to study the underlying mechanisms of influenza B virus transmission. PMID:22301149

  5. Origin of the European avian-like swine influenza viruses.

    PubMed

    Krumbholz, Andi; Lange, Jeannette; Sauerbrei, Andreas; Groth, Marco; Platzer, Matthias; Kanrai, Pumaree; Pleschka, Stephan; Scholtissek, Christoph; Büttner, Mathias; Dürrwald, Ralf; Zell, Roland

    2014-11-01

    The avian-like swine influenza viruses emerged in 1979 in Belgium and Germany. Thereafter, they spread through many European swine-producing countries, replaced the circulating classical swine H1N1 influenza viruses, and became endemic. Serological and subsequent molecular data indicated an avian source, but details remained obscure due to a lack of relevant avian influenza virus sequence data. Here, the origin of the European avian-like swine influenza viruses was analysed using a collection of 16 European swine H1N1 influenza viruses sampled in 1979-1981 in Germany, the Netherlands, Belgium, Italy and France, as well as several contemporaneous avian influenza viruses of various serotypes. The phylogenetic trees suggested a triple reassortant with a unique genotype constellation. Time-resolved maximum clade credibility trees indicated times to the most recent common ancestors of 34-46 years (before 2008) depending on the RNA segment and the method of tree inference. PMID:25073465

  6. Edible bird's nest extract inhibits influenza virus infection.

    PubMed

    Guo, Chao-Tan; Takahashi, Tadanobu; Bukawa, Wakoto; Takahashi, Noriko; Yagi, Hirokazu; Kato, Koichi; Hidari, Kazuya I-P Jwa; Miyamoto, Daisei; Suzuki, Takashi; Suzuki, Yasuo

    2006-07-01

    Edible bird's nest (EBN) is the nest of the swift that is made from its saliva. Although EBN has been widely used for enhancing immunocompetence, its antiviral efficacy has not been studied in detail. We found that EBN extract could strongly inhibit infection with influenza viruses in a host range-independent manner when it was hydrolyzed with Pancreatin F. Western blotting assay showed that the EBN extract bound to influenza virus. Furthermore, EBN extract could neutralize the infection of MDCK cells with influenza viruses and inhibit hemagglutination of influenza viruses to erythrocytes, but it could not inhibit the activity of influenza virus sialidase. Fluorometric HPLC indicated that the major molecular species of sialic acid in EBN is N-acetylneuraminic acid. The results suggest that EBN is a safe and valid natural source for the prevention of influenza viruses. PMID:16581142

  7. EXISTING ANTIVIRALS ARE EFFECTIVE AGAINST INFLUENZA VIRUSES WITH GENES FROM THE 1918 PANDEMIC VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 1918 influenza pandemic caused more than 20 million deaths worldwide. Under biosafety level 3Ag containment, a recombinant influenza virus bearing the 1918 influenza virus hemagglutinin (HA) and neuraminidase (NA) was generated. This virus is highly virulent in mice, pointing to the 1918 HA and...

  8. Global migration of influenza A viruses in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The emergence of the 2009 A/H1N1 pandemic virus underscores the importance of understanding how influenza A viruses evolve in swine on a global scale. To reveal the frequency, patterns and drivers of the spread of swine influenza virus globally, we conducted the largest phylogenetic analysis of swin...

  9. Novel routes of transmission of influenza viruses in poultry species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to develop better control measures against influenza it’s necessary to understand how the virus transmits in different species. The presence of avian and swine influenza virus genes in the 2009 novel H1N1 pandemic virus (pH1N1) raises the potential for infection in poultry following exposur...

  10. Pathogenesis and pathobiology of avian influenza virus infection in birds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian Influenza (AI) viruses vary in their ability to produce infection, disease and death in different bird species. Based on the pathobiological features in chickens, AI viruses are categorized as, low (LP) and high pathogenicity (HP). Typically, LPAI (low pathogenicity avian influenza) viruses ...

  11. Cross talk between animal and human influenza viruses.

    PubMed

    Ozawa, Makoto; Kawaoka, Yoshihiro

    2013-01-01

    Although outbreaks of highly pathogenic avian influenza in wild and domestic birds have been posing the threat of a new influenza pandemic for the past decade, the first pandemic of the twenty-first century came from swine viruses. This fact emphasizes the complexity of influenza viral ecology and the difficulty of predicting influenza viral dynamics. Complete control of influenza viruses seems impossible. However, we must minimize the impact of animal and human influenza outbreaks by learning lessons from past experiences and recognizing the current status. Here, we review the most recent influenza virology data in the veterinary field, including aspects of zoonotic agents and recent studies that assess the pandemic potential of H5N1 highly pathogenic avian influenza viruses. PMID:25387011

  12. Animal models for influenza virus pathogenesis, transmission, and immunology

    PubMed Central

    Thangavel, Rajagowthamee R.; Bouvier, Nicole M.

    2014-01-01

    In humans, infection with an influenza A or B virus manifests typically as an acute and self-limited upper respiratory tract illness characterized by fever, cough, sore throat, and malaise. However, influenza can present along a broad spectrum of disease, ranging from sub-clinical or even asymptomatic infection to a severe primary viral pneumonia requiring advanced medical supportive care. Disease severity depends upon the virulence of the influenza virus strain and the immune competence and previous influenza exposures of the patient. Animal models are used in influenza research not only to elucidate the viral and host factors that affect influenza disease outcomes in and spread among susceptible hosts, but also to evaluate interventions designed to prevent or reduce influenza morbidity and mortality in man. This review will focus on the three animal models currently used most frequently in influenza virus research -- mice, ferrets, and guinea pigs -- and discuss the advantages and disadvantages of each. PMID:24709389

  13. Recombinant Hemagglutinin and Virus-Like Particle Vaccines for H7N9 Influenza Virus

    PubMed Central

    Li, Xiaohui; Pushko, Peter; Tretyakova, Irina

    2015-01-01

    Cases of H7N9 human infection were caused by a novel, avian-origin H7N9 influenza A virus that emerged in eastern China in 2013. Clusters of human disease were identified in many cities in China, with mortality rates approaching 30%. Pandemic concerns were raised, as historically, influenza pandemics were caused by introduction of novel influenza A viruses into immunologically naïve human population. Currently, there are no approved human vaccines for H7N9 viruses. Recombinant protein vaccine approaches have advantages in safety and manufacturing. In this review, we focused on evaluation of the expression of recombinant hemagglutinin (rHA) proteins as candidate vaccines for H7N9 influenza, with the emphasis on the role of oligomeric and particulate structures in immunogenicity and protection. Challenges in preparation of broadly protective influenza vaccines are discussed, and examples of broadly protective vaccines are presented including rHA stem epitope vaccines, as well as recently introduced experimental multi-HA VLP vaccines. PMID:26523241

  14. Live-attenuated influenza A virus vaccines using a B virus backbone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The currently FDA-licensed live attenuated influenza virus vaccine contains a trivalent mixture of types A (H1N1 and H3N2) and B vaccine viruses. The two A virus vaccines have the backbone of a cold-adapted influenza A virus and the B virus vaccine has the six backbone segments derived from a cold-...

  15. Modified Vaccinia Virus Ankara Encoding Influenza Virus Hemagglutinin Induces Heterosubtypic Immunity in Macaques

    PubMed Central

    Florek, Nicholas W.; Weinfurter, Jason T.; Jegaskanda, Sinthujan; Brewoo, Joseph N.; Powell, Tim D.; Young, Ginger R.; Das, Subash C.; Hatta, Masato; Broman, Karl W.; Hungnes, Olav; Dudman, Susanne G.; Kawaoka, Yoshihiro; Kent, Stephen J.; Stinchcomb, Dan T.

    2014-01-01

    ABSTRACT Current influenza virus vaccines primarily aim to induce neutralizing antibodies (NAbs). Modified vaccinia virus Ankara (MVA) is a safe and well-characterized vector for inducing both antibody and cellular immunity. We evaluated the immunogenicity and protective efficacy of MVA encoding influenza virus hemagglutinin (HA) and/or nucleoprotein (NP) in cynomolgus macaques. Animals were given 2 doses of MVA-based vaccines 4 weeks apart and were challenged with a 2009 pandemic H1N1 isolate (H1N1pdm) 8 weeks after the last vaccination. MVA-based vaccines encoding HA induced potent serum antibody responses against homologous H1 or H5 HAs but did not stimulate strong T cell responses prior to challenge. However, animals that received MVA encoding influenza virus HA and/or NP had high frequencies of virus-specific CD4+ and CD8+ T cell responses within the first 7 days of H1N1pdm infection, while animals vaccinated with MVA encoding irrelevant antigens did not. We detected little or no H1N1pdm replication in animals that received vaccines encoding H1 (homologous) HA, while a vaccine encoding NP from an H5N1 isolate afforded no protection. Surprisingly, H1N1pdm viral shedding was reduced in animals vaccinated with MVA encoding HA and NP from an H5N1 isolate. This reduced shedding was associated with cross-reactive antibodies capable of mediating antibody-dependent cellular cytotoxicity (ADCC) effector functions. Our results suggest that ADCC plays a role in cross-protective immunity against influenza. Vaccines optimized to stimulate cross-reactive antibodies with ADCC function may provide an important measure of protection against emerging influenza viruses when NAbs are ineffective. IMPORTANCE Current influenza vaccines are designed to elicit neutralizing antibodies (NAbs). Vaccine-induced NAbs typically are effective but highly specific for particular virus strains. Consequently, current vaccines are poorly suited for preventing the spread of newly emerging

  16. The global antigenic diversity of swine influenza A viruses.

    PubMed

    Lewis, Nicola S; Russell, Colin A; Langat, Pinky; Anderson, Tavis K; Berger, Kathryn; Bielejec, Filip; Burke, David F; Dudas, Gytis; Fonville, Judith M; Fouchier, Ron Am; Kellam, Paul; Koel, Bjorn F; Lemey, Philippe; Nguyen, Tung; Nuansrichy, Bundit; Peiris, Js Malik; Saito, Takehiko; Simon, Gaelle; Skepner, Eugene; Takemae, Nobuhiro; Webby, Richard J; Van Reeth, Kristien; Brookes, Sharon M; Larsen, Lars; Watson, Simon J; Brown, Ian H; Vincent, Amy L

    2016-01-01

    Swine influenza presents a substantial disease burden for pig populations worldwide and poses a potential pandemic threat to humans. There is considerable diversity in both H1 and H3 influenza viruses circulating in swine due to the frequent introductions of viruses from humans and birds coupled with geographic segregation of global swine populations. Much of this diversity is characterized genetically but the antigenic diversity of these viruses is poorly understood. Critically, the antigenic diversity shapes the risk profile of swine influenza viruses in terms of their epizootic and pandemic potential. Here, using the most comprehensive set of swine influenza virus antigenic data compiled to date, we quantify the antigenic diversity of swine influenza viruses on a multi-continental scale. The substantial antigenic diversity of recently circulating viruses in different parts of the world adds complexity to the risk profiles for the movement of swine and the potential for swine-derived infections in humans. PMID:27113719

  17. Reverse genetics based rgH5N2 vaccine provides protection against high dose challenge of H5N1 avian influenza virus in chicken.

    PubMed

    Bhatia, S; Khandia, R; Sood, R; Bhat, S; Siddiqui, A; Jahagirdhar, G; Mishra, S; Mishra, A; Pateriya, A K; Kulkarni, D D

    2016-08-01

    An inactivated vaccine was developed using the rgH5N2 virus (6 + 2 reassortant) generated by plasmid based reverse genetics system (RGS) with WSN/33/H1N1 as backbone virus. Following mutation of the basic amino acid cleavage site RRRKKR*GLF to IETR*GLF, the H5-HA (haemagglutinin) gene of the selected donor H5N1 virus (A/chicken/West Bengal/80995/2008) of antigenic clade 2.2 was used along with the N2-NA gene from H9N2 field isolate (A/chicken/Uttar Pradesh/2543/2004) for generation of the rgH5N2 virus. A single dose (0.5 ml/bird) of the inactivated rgH5N2 vaccine protected 100% of the vaccinated chickens (n = 10) on 28(th) dpv (early challenge) and 90% of the vaccinated chickens (n = 10) on 200(th) dpv (late challenge) against high dose challenge with HPAI virus (10(9) EID50/bird). Challenge virus shedding via oropharynx and cloaca of the vaccinated chickens was detectable by realtime RT-PCR during 1-5 dpc and 1-9 days dpc in the early and the late challenge, respectively. The protective level of antibodies (mean HI titre > 128) was maintained without booster vaccination for 200 days. The present study provides the experimental evidence about the extent of protection provided by a reverse genetics based vaccine for clade 2.2 H5N1 viruses against challenge with high dose of field virus at two different time points (28 dpv and 200 dpv). The challenge study is uniquely different from the previous similar experiments on account of 1000 times higher dose of challenge and protection at 200 dpv. The protection and virus shedding data of the study may be useful for countries planning to use H5 vaccine in poultry especially against the clade 2.2 H5N1 viruses. PMID:27296706

  18. Influenza virus vaccine for neglected hosts: horses and dogs.

    PubMed

    Na, Woonsung; Yeom, Minjoo; Yuk, Huijoon; Moon, Hyoungjoon; Kang, Bokyu; Song, Daesub

    2016-07-01

    This study provides information regarding vaccine research and the epidemiology of influenza virus in neglected hosts (horses and dogs). Equine influenza virus (EIV) causes a highly contagious disease in horses and other equids, and outbreaks have occurred worldwide. EIV has resulted in costly damage to the horse industry and has the ability of cross the host species barrier from horses to dogs. Canine influenza is a virus of equine or avian origin and infects companion animals that live in close contact with humans; this results in possible exposure to the seasonal epizootic influenza virus. There have been case reports of genetic reassortment between human and canine influenza viruses, which results in high virulence and the ability of transmission to ferrets. This emphasizes the need for vaccine research on neglected hosts to update knowledge on current strains and to advance technology for controlling influenza outbreaks for public health. PMID:27489801

  19. Influenza virus vaccine for neglected hosts: horses and dogs

    PubMed Central

    2016-01-01

    This study provides information regarding vaccine research and the epidemiology of influenza virus in neglected hosts (horses and dogs). Equine influenza virus (EIV) causes a highly contagious disease in horses and other equids, and outbreaks have occurred worldwide. EIV has resulted in costly damage to the horse industry and has the ability of cross the host species barrier from horses to dogs. Canine influenza is a virus of equine or avian origin and infects companion animals that live in close contact with humans; this results in possible exposure to the seasonal epizootic influenza virus. There have been case reports of genetic reassortment between human and canine influenza viruses, which results in high virulence and the ability of transmission to ferrets. This emphasizes the need for vaccine research on neglected hosts to update knowledge on current strains and to advance technology for controlling influenza outbreaks for public health. PMID:27489801

  20. Heterosubtypic T-Cell Immunity to Influenza in Humans: Challenges for Universal T-Cell Influenza Vaccines

    PubMed Central

    Sridhar, Saranya

    2016-01-01

    Influenza A virus (IAV) remains a significant global health issue causing annual epidemics, pandemics, and sporadic human infections with highly pathogenic avian or swine influenza viruses. Current inactivated and live vaccines are the mainstay of the public health response to influenza, although vaccine efficacy is lower against antigenically distinct viral strains. The first pandemic of the twenty-first century underlined the urgent need to develop new vaccines capable of protecting against a broad range of influenza strains. Such “universal” influenza vaccines are based on the idea of heterosubtypic immunity, wherein immune responses to epitopes conserved across IAV strains can confer protection against subsequent infection and disease. T-cells recognizing conserved antigens are a key contributor in reducing viral load and limiting disease severity during heterosubtypic infection in animal models. Recent studies undertaken during the 2009 H1N1 pandemic provided key insights into the role of cross-reactive T-cells in mediating heterosubtypic protection in humans. This review focuses on human influenza to discuss the epidemiological observations that underpin cross-protective immunity, the role of T-cells as key players in mediating heterosubtypic immunity including recent data from natural history cohort studies and the ongoing clinical development of T-cell-inducing universal influenza vaccines. The challenges and knowledge gaps for developing vaccines to generate long-lived protective T-cell responses is discussed. PMID:27242800

  1. Heterosubtypic T-Cell Immunity to Influenza in Humans: Challenges for Universal T-Cell Influenza Vaccines.

    PubMed

    Sridhar, Saranya

    2016-01-01

    Influenza A virus (IAV) remains a significant global health issue causing annual epidemics, pandemics, and sporadic human infections with highly pathogenic avian or swine influenza viruses. Current inactivated and live vaccines are the mainstay of the public health response to influenza, although vaccine efficacy is lower against antigenically distinct viral strains. The first pandemic of the twenty-first century underlined the urgent need to develop new vaccines capable of protecting against a broad range of influenza strains. Such "universal" influenza vaccines are based on the idea of heterosubtypic immunity, wherein immune responses to epitopes conserved across IAV strains can confer protection against subsequent infection and disease. T-cells recognizing conserved antigens are a key contributor in reducing viral load and limiting disease severity during heterosubtypic infection in animal models. Recent studies undertaken during the 2009 H1N1 pandemic provided key insights into the role of cross-reactive T-cells in mediating heterosubtypic protection in humans. This review focuses on human influenza to discuss the epidemiological observations that underpin cross-protective immunity, the role of T-cells as key players in mediating heterosubtypic immunity including recent data from natural history cohort studies and the ongoing clinical development of T-cell-inducing universal influenza vaccines. The challenges and knowledge gaps for developing vaccines to generate long-lived protective T-cell responses is discussed. PMID:27242800

  2. Avian Influenza Virus and DIVA Strategies.

    PubMed

    Hasan, Noor Haliza; Ignjatovic, Jagoda; Peaston, Anne; Hemmatzadeh, Farhid

    2016-05-01

    Vaccination is becoming a more acceptable option in the effort to eradicate avian influenza viruses (AIV) from commercial poultry, especially in countries where AIV is endemic. The main concern surrounding this option has been the inability of the conventional serological tests to differentiate antibodies produced due to vaccination from antibodies produced in response to virus infection. In attempts to address this issue, at least six strategies have been formulated, aiming to differentiate infected from vaccinated animals (DIVA), namely (i) sentinel birds, (ii) subunit vaccine, (iii) heterologous neuraminidase (NA), (iv) nonstructural 1 (NS1) protein, (v) matrix 2 ectodomain (M2e) protein, and (vi) haemagglutinin subunit 2 (HA2) glycoprotein. This short review briefly discusses the strengths and limitations of these DIVA strategies, together with the feasibility and practicality of the options as a part of the surveillance program directed toward the eventual eradication of AIV from poultry in countries where highly pathogenic avian influenza is endemic. PMID:26900835

  3. The prospects and challenges of universal vaccines for influenza

    PubMed Central

    Subbarao, Kanta; Matsuoka, Yumiko

    2013-01-01

    Vaccination is the most effective way to reduce the impact of epidemic as well as pandemic influenza. However, the licensed inactivated influenza vaccine induces strain-specific immunity and must be updated annually. When novel viruses appear, matched vaccines are not likely to be available in time for the first wave of a pandemic. Yet, the enormous diversity of influenza A viruses in nature makes it impossible to predict which subtype or strain will cause the next pandemic. Several recent scientific advances have generated renewed enthusiasm and hope for universal vaccines that will induce broad protection from a range of influenza viruses. PMID:23685068

  4. TMPRSS2 Independency for Haemagglutinin Cleavage In Vivo Differentiates Influenza B Virus from Influenza A Virus.

    PubMed

    Sakai, Kouji; Ami, Yasushi; Nakajima, Noriko; Nakajima, Katsuhiro; Kitazawa, Minori; Anraku, Masaki; Takayama, Ikuyo; Sangsriratanakul, Natthanan; Komura, Miyuki; Sato, Yuko; Asanuma, Hideki; Takashita, Emi; Komase, Katsuhiro; Takehara, Kazuaki; Tashiro, Masato; Hasegawa, Hideki; Odagiri, Takato; Takeda, Makoto

    2016-01-01

    Influenza A and B viruses show clear differences in their host specificity and pandemic potential. Recent studies have revealed that the host protease TMPRSS2 plays an essential role for proteolytic activation of H1, H3, and H7 subtype strains of influenza A virus (IAV) in vivo. IAV possessing a monobasic cleavage site in the haemagglutinin (HA) protein replicates poorly in TMPRSS2 knockout mice owing to insufficient HA cleavage. In the present study, human isolates of influenza B virus (IBV) strains and a mouse-adapted IBV strain were analysed. The data showed that IBV successfully underwent HA cleavage in TMPRSS2 knockout mice, and that the mouse-adapted strain was fully pathogenic to these mice. The present data demonstrate a clear difference between IAV and IBV in their molecular mechanisms for spreading in vivo. PMID:27389476

  5. TMPRSS2 Independency for Haemagglutinin Cleavage In Vivo Differentiates Influenza B Virus from Influenza A Virus

    PubMed Central

    Sakai, Kouji; Ami, Yasushi; Nakajima, Noriko; Nakajima, Katsuhiro; Kitazawa, Minori; Anraku, Masaki; Takayama, Ikuyo; Sangsriratanakul, Natthanan; Komura, Miyuki; Sato, Yuko; Asanuma, Hideki; Takashita, Emi; Komase, Katsuhiro; Takehara, Kazuaki; Tashiro, Masato; Hasegawa, Hideki; Odagiri, Takato; Takeda, Makoto

    2016-01-01

    Influenza A and B viruses show clear differences in their host specificity and pandemic potential. Recent studies have revealed that the host protease TMPRSS2 plays an essential role for proteolytic activation of H1, H3, and H7 subtype strains of influenza A virus (IAV) in vivo. IAV possessing a monobasic cleavage site in the haemagglutinin (HA) protein replicates poorly in TMPRSS2 knockout mice owing to insufficient HA cleavage. In the present study, human isolates of influenza B virus (IBV) strains and a mouse-adapted IBV strain were analysed. The data showed that IBV successfully underwent HA cleavage in TMPRSS2 knockout mice, and that the mouse-adapted strain was fully pathogenic to these mice. The present data demonstrate a clear difference between IAV and IBV in their molecular mechanisms for spreading in vivo. PMID:27389476

  6. Amantadine resistance among highly pathogenic avian influenza viruses (H5N1) isolated from India.

    PubMed

    Jacob, Aron; Sood, Richa; Chanu, Kh Victoria; Bhatia, Sandeep; Khandia, Rekha; Pateriya, A K; Nagarajan, S; Dimri, U; Kulkarni, D D

    2016-02-01

    Emergence of antiviral resistance among H5N1 avian influenza viruses is the major challenge in the control of pandemic influenza. Matrix 2 (M2) inhibitors (amantadine and rimantadine) and neuraminidase inhibitors (oseltamivir and zanamivir) are the two classes of antiviral agents that are specifically active against influenza viruses and are used for both treatment and prophylaxis of influenza infections. Amantadine targets the M2 ion channel of influenza A virus and interrupts virus life cycle through blockade of hydrogen ion influx. This prevents uncoating of the virus in infected host cells which impedes the release of ribonucleoprotein required for transcription and replication of virion in the nucleus. The present study was carried out to review the status of amantadine resistance in H5N1 viruses isolated from India and to study their replicative capability. Results of the study revealed resistance to amantadine in antiviral assay among four H5N1 viruses out of which two viruses had Serine 31 Asparagine (AGT-AAT i.e., S31N) mutation and two had Valine 27 Alanine (GTT-GCT i.e., V27A) mutation. The four resistant viruses not only exhibited significant difference in effective concentration 50% (EC50) values of amantadine hydrochloride from that of susceptible viruses (P < 0.0001) but also showed significant difference between two different types (S31N and V27A) of mutant viruses (P < 0.05). Resistance to amantadine could also be demonstrated in a simple HA test after replication of the viruses in MDCK cells in presence of amantadine. The study identifies the correlation between in vitro antiviral assay and presence of established molecular markers of resistance, the retention of replicative capacity in the presence of amantadine hydrochloride by the resistant viruses and the emergence of resistant mutations against amantadine among avian influenza viruses (H5N1) without selective drug pressure. PMID:26639679

  7. Chloroquine is effective against influenza A virus in vitro but not in vivo

    PubMed Central

    Vigerust, David J.; McCullers, Jonathan A.

    2008-01-01

    Background  Chloroquine is an inexpensive and widely available 9‐aminoquinolone used in the management of malaria. Recently, in vitro assays suggest that chloroquine may have utility in the treatment of several viral infections including influenza. Objectives  We sought to test whether chloroquine is effective against influenza in vivo in relevant animal models. Methods  The effectiveness of chloroquine at preventing or ameliorating influenza following viral challenge was assessed in established mouse and ferret disease models. Results  Although active against influenza viruses in vitro, chloroquine did not prevent the weight loss associated with influenza virus infection in mice after challenge with viruses expressing an H1 or H3 hemagglutinin protein. Similarly, clinical signs and viral replication in the nose of ferrets were not altered by treatment. Conclusions  Although in vitro results were promising, chloroquine was not effective as preventive therapy in vivo in standard mouse and ferret models of influenza virus infection. This dampens enthusiasm for the potential utility of the drug for humans with influenza. PMID:19453426

  8. Sialic acid content in human saliva and anti-influenza activity against human and avian influenza viruses.

    PubMed

    Limsuwat, Nattavatchara; Suptawiwat, Ornpreya; Boonarkart, Chompunuch; Puthavathana, Pilaipan; Wiriyarat, Witthawat; Auewarakul, Prasert

    2016-03-01

    It was shown previously that human saliva has higher antiviral activity against human influenza viruses than against H5N1 highly pathogenic avian influenza viruses, and that the major anti-influenza activity was associated with sialic-acid-containing molecules. To further characterize the differential susceptibility to saliva among influenza viruses, seasonal influenza A and B virus, pandemic H1N1 virus, and 15 subtypes of avian influenza virus were tested for their susceptibility to human and chicken saliva. Human saliva showed higher hemagglutination inhibition (HI) and neutralization (NT) titers against seasonal influenza A virus and the pandemic H1N1 viruses than against influenza B virus and most avian influenza viruses, except for H9N2 and H12N9 avian influenza viruses, which showed high HI and NT titers. To understand the nature of sialic-acid-containing anti-influenza factors in human saliva, α2,3- and α2,6-linked sialic acid was measured in human saliva samples using a lectin binding and dot blot assay. α2,6-linked sialic acid was found to be more abundant than α2,3-linked sialic acid, and a seasonal H1N1 influenza virus bound more efficiently to human saliva than an H5N1 virus in a dot blot analysis. These data indicated that human saliva contains the sialic acid type corresponding to the binding preference of seasonal influenza viruses. PMID:26671828

  9. Vaccination with NS1-truncated H3N2 swine influenza virus primes T cells and confers cross-protection against an H1N1 heterosubtypic challenge in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diversity of contemporary swine influenza virus (SIV) strains impedes effective immunization of swine herds. Mucosally delivered, attenuated virus vaccines are one approach with potential to provide broad cross-protection. Reverse genetics-derived H3N2 SIV virus with truncated NS1 (NS1delta126 T...

  10. Attenuation of human influenza a viruses

    PubMed Central

    Beare, A. S.; Bynoe, M. L.

    1969-01-01

    The attenuation of two human influenza A viruses has been carried out, using the selection of inhibitor-resistant strains and multiple passages at low temperatures. A virus related to A2/Tokyo/3/67 was obtained in an inhibitor-resistant form. When this was compared with the inhibitor-sensitive strain in a volunteer trial it was relatively non-pathogenic. The second virus, A2/Hongkong/1/68, was subjected to much longer treatment, but nevertheless remained slightly sensitive to serum inhibitor. When given to volunteers it was less pathogenic than before but attenuation was incomplete. A2/Hongkong/1/68 was also modified by passage at low temperatures. Many of these passages are apparently necessary for full attenuation. All attenuated viruses were infective and antigenic. PMID:4900146

  11. Correlation between Virus Replication and Antibody Responses in Macaques following Infection with Pandemic Influenza A Virus

    PubMed Central

    Koopman, Gerrit; Dekking, Liesbeth; Mortier, Daniëlla; Nieuwenhuis, Ivonne G.; van Heteren, Melanie; Kuipers, Harmjan; Remarque, Edmond J.; Radošević, Katarina; Bogers, Willy M. J. M.

    2015-01-01

    ABSTRACT Influenza virus infection of nonhuman primates is a well-established animal model for studying pathogenesis and for evaluating prophylactic and therapeutic intervention strategies. However, usually a standard dose is used for the infection, and there is no information on the relation between challenge dose and virus replication or the induction of immune responses. Such information is also very scarce for humans and largely confined to evaluation of attenuated virus strains. Here, we have compared the effect of a commonly used dose (4 × 106 50% tissue culture infective doses) versus a 100-fold-higher dose, administered by intrabronchial installation, to two groups of 6 cynomolgus macaques. Animals infected with the high virus dose showed more fever and had higher peak levels of gamma interferon in the blood. However, virus replication in the trachea was not significantly different between the groups, although in 2 out of 6 animals from the high-dose group it was present at higher levels and for a longer duration. The virus-specific antibody response was not significantly different between the groups. However, antibody enzyme-linked immunosorbent assay, virus neutralization, and hemagglutination inhibition antibody titers correlated with cumulative virus production in the trachea. In conclusion, using influenza virus infection in cynomolgus macaques as a model, we demonstrated a relationship between the level of virus production upon infection and induction of functional antibody responses against the virus. IMPORTANCE There is only very limited information on the effect of virus inoculation dose on the level of virus production and the induction of adaptive immune responses in humans or nonhuman primates. We found only a marginal and variable effect of virus dose on virus production in the trachea but a significant effect on body temperature. The induction of functional antibody responses, including virus neutralization titer, hemagglutination inhibition

  12. Global circulation patterns of seasonal influenza viruses vary with antigenic drift

    NASA Astrophysics Data System (ADS)

    Bedford, Trevor; Riley, Steven; Barr, Ian G.; Broor, Shobha; Chadha, Mandeep; Cox, Nancy J.; Daniels, Rodney S.; Gunasekaran, C. Palani; Hurt, Aeron C.; Kelso, Anne; Klimov, Alexander; Lewis, Nicola S.; Li, Xiyan; McCauley, John W.; Odagiri, Takato; Potdar, Varsha; Rambaut, Andrew; Shu, Yuelong; Skepner, Eugene; Smith, Derek J.; Suchard, Marc A.; Tashiro, Masato; Wang, Dayan; Xu, Xiyan; Lemey, Philippe; Russell, Colin A.

    2015-07-01

    Understanding the spatiotemporal patterns of emergence and circulation of new human seasonal influenza virus variants is a key scientific and public health challenge. The global circulation patterns of influenza A/H3N2 viruses are well characterized, but the patterns of A/H1N1 and B viruses have remained largely unexplored. Here we show that the global circulation patterns of A/H1N1 (up to 2009), B/Victoria, and B/Yamagata viruses differ substantially from those of A/H3N2 viruses, on the basis of analyses of 9,604 haemagglutinin sequences of human seasonal influenza viruses from 2000 to 2012. Whereas genetic variants of A/H3N2 viruses did not persist locally between epidemics and were reseeded from East and Southeast Asia, genetic variants of A/H1N1 and B viruses persisted across several seasons and exhibited complex global dynamics with East and Southeast Asia playing a limited role in disseminating new variants. The less frequent global movement of influenza A/H1N1 and B viruses coincided with slower rates of antigenic evolution, lower ages of infection, and smaller, less frequent epidemics compared to A/H3N2 viruses. Detailed epidemic models support differences in age of infection, combined with the less frequent travel of children, as probable drivers of the differences in the patterns of global circulation, suggesting a complex interaction between virus evolution, epidemiology, and human behaviour.

  13. Influenza virus infection, ozone exposure, and fibrogenesis.

    PubMed

    Jakab, G J; Bassett, D J

    1990-05-01

    Oxidant exposure following chemically induced lung injury exacerbates the tendency to develop pulmonary fibrosis. Influenza virus pneumonitis causes severe acute lung damage that, upon resolution, is followed by a persistent alveolitis and parenchymal changes characterized by patchy interstitial pneumonia and collagen deposition in the affected areas. To determine whether oxidant exposure exacerbates the virus-induced alveolitis and residual lung damage, mice were infected by aerosol inhalation with influenza A virus and continuously exposed to 0.5 ppm ozone or ambient air. Noninfected control mice were exposed to either ambient air or ozone. On various days during the first month after infection, groups of mice were sacrificed and their lungs assessed for acute injury (lung lavage albumin, total and differential cell counts, wet/dry ratios, and morphometry). At 30, 60, 90, and 120 days after infection, groups of mice were sacrificed for total and differential lavage cell counts, lung hydroxyproline content, and morphometric analysis. Ozone exposure did not alter the proliferation of virus in the lungs as quantitated by infectious virus titers of lung homogenates at 1, 4, 7, 10, and 15 days after virus infection but mitigated the virus-induced acute lung injury by approximately 50%. After Day 30 a shift in the character of the pulmonary lesions was observed in that continuous exposure to ozone potentiated the postinfluenzal alveolitis and structural changes in the lung parenchyma. Additional studies suggest that the mechanism for the enhanced postinfluenzal lung damage may be related to the oxidant impairing the repair process of the acute influenzal lung damage. These data demonstrate that ozone exposure mitigates acute virus-induced lung injury and potentiates residual lung damage. PMID:2339849

  14. Recent progress in designing inhibitors that target the drug-resistant M2 proton channels from the influenza A viruses.

    PubMed

    Wang, Jun; Li, Fang; Ma, Chunlong

    2015-07-01

    Influenza viruses are the causative agents for seasonal influenza, which results in thousands of deaths and millions of hospitalizations each year. Moreover, sporadic transmission of avian or swan influenza viruses to humans often leads to an influenza pandemic, as there is no preimmunity in the human body to fight against such novel strains. The metastable genome of the influenza viruses, coupled with the reassortment of different strains from a wide range of host origins, leads to the continuous evolution of the influenza virus diversity. Such characteristics of influenza viruses present a grand challenge in devising therapeutic strategies to combat influenza virus infection. This review summarizes recent progress in designing small molecule inhibitors that target the drug-resistant influenza A virus M2 proton channels and highlights the contribution of mechanistic studies of proton conductance to drug discovery. The lessons learned throughout the course of M2 drug discovery might provide insights for designing inhibitors that target other therapeutically important ion channels. PMID:25663018

  15. Characterization of influenza virus among influenza like illness cases in Mumbai, India.

    PubMed

    Roy, Soumen; Dahake, Ritwik; Patil, Deepak; Tawde, Shweta; Mukherjee, Sandeepan; Athlekar, Shrikant; Chowdhary, Abhay; Deshmukh, Ranjana

    2014-01-01

    The present study was carried out to monitor influenza viruses by identifying the virus and studying the seasonal variation during 2007-2009 in Mumbai. A total of 193 clinical respiratory samples (nasal and throat swab) were collected from patients having influenza like illness in Mumbai region. One-step real-time reverse-transcriptase PCR (rRTPCR) was used to detect Influenza type A (H1 and H3) and Influenza type B virus. Isolation of the virus was carried out using in vitro system which was further confirmed and typed by hemagglutination assay and hemagglutination inhibition assay. Out of 193 samples 24 (12.4 3%) samples tested positive for influenza virus, of which 13 (6.73 %) were influenza type A virus and 10 (5.18 %) were influenza type B virus, while 1 sample (0.51 %) was positive for both. By culture methods, 3 (1.55 %) viral isolates were obtained. All the three isolates were found to be Influenza type B/Malaysia (Victoria lineage) by Hemagglutination Inhibition Assay. The data generated from the present study reveals that both Influenza type A and B are prevalent in Mumbai with considerable activity. The peak activity was observed during monsoon season. PMID:25674606

  16. New World Bats Harbor Diverse Influenza A Viruses

    PubMed Central

    Tong, Suxiang; Zhu, Xueyong; Li, Yan; Shi, Mang; Zhang, Jing; Bourgeois, Melissa; Yang, Hua; Chen, Xianfeng; Recuenco, Sergio; Gomez, Jorge; Chen, Li-Mei; Johnson, Adam; Tao, Ying; Dreyfus, Cyrille; Yu, Wenli; McBride, Ryan; Carney, Paul J.; Gilbert, Amy T.; Chang, Jessie; Guo, Zhu; Davis, Charles T.; Paulson, James C.; Stevens, James; Rupprecht, Charles E.; Holmes, Edward C.; Wilson, Ian A.; Donis, Ruben O.

    2013-01-01

    Aquatic birds harbor diverse influenza A viruses and are a major viral reservoir in nature. The recent discovery of influenza viruses of a new H17N10 subtype in Central American fruit bats suggests that other New World species may similarly carry divergent influenza viruses. Using consensus degenerate RT-PCR, we identified a novel influenza A virus, designated as H18N11, in a flat-faced fruit bat (Artibeus planirostris) from Peru. Serologic studies with the recombinant H18 protein indicated that several Peruvian bat species were infected by this virus. Phylogenetic analyses demonstrate that, in some gene segments, New World bats harbor more influenza virus genetic diversity than all other mammalian and avian species combined, indicative of a long-standing host-virus association. Structural and functional analyses of the hemagglutinin and neuraminidase indicate that sialic acid is not a ligand for virus attachment nor a substrate for release, suggesting a unique mode of influenza A virus attachment and activation of membrane fusion for entry into host cells. Taken together, these findings indicate that bats constitute a potentially important and likely ancient reservoir for a diverse pool of influenza viruses. PMID:24130481

  17. Sequencing of avian influenza virus genomes following random amplification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian Influenza (AI) is a significant disease of birds and a threat to humans. Recently, as a result of the emergence of Asian H5N1 viruses capable of zoonotic spread, wild and domestic bird surveillance for Avian Influenza viruses (AIV) has increased worldwide, requiring the development of fast a...

  18. Saikosaponin A inhibits influenza A virus replication and lung immunopathology

    PubMed Central

    Zhao, Yaqin; Ling, Fangfang; Xiao, Kun; Li, Qian; Li, Bin; Lu, Chunni; Qi, Wenbao; Zeng, Zhenling; Liao, Ming; Liu, Yahong; Chen, Weisan

    2015-01-01

    Fatal influenza outcomes result from a combination of rapid virus replication and collateral lung tissue damage caused by exaggerated pro-inflammatory host immune cell responses. There are few therapeutic agents that target both biological processes for the attenuation of influenza-induced lung pathology. We show that Saikosaponin A, a bioactive triterpene saponin with previouslyestablished anti-inflammatory effects, demonstrates both in vitro and in vivo anti-viral activity against influenza A virus infections. Saikosaponin A attenuated the replication of three different influenza A virus strains, including a highly pathogenic H5N1 strain, in human alveolar epithelial A549 cells. This anti-viral activity occurred through both downregulation of NF-κB signaling and caspase 3-dependent virus ribonucleoprotein nuclear export as demonstrated by NF-κB subunit p65 and influenza virus nucleoprotein nuclear translocation studies in influenza virus infected A549 cells. Critically, Saikosaponin A also attenuated viral replication, aberrant pro-inflammatory cytokine production and lung histopathology in the widely established H1N1 PR8 model of influenza A virus lethality in C57BL/6 mice. Flow cytometry studies of mouse bronchoalveolar lavage cells revealed that SSa exerted immunomodulatory effects through a selective attenuation of lung neutrophil and monocyte recruitment during the early peak of the innate immune response to PR8 infection. Altogether, our results indicate that Saikosaponin A possesses novel therapeutic potential for the treatment of pathological influenza virus infections. PMID:26637810

  19. Quantification of Influenza Virus RNA in Aerosols in Patient Rooms

    PubMed Central

    Leung, Nancy H. L.; Zhou, Jie; Chu, Daniel K. W.; Yu, Han; Lindsley, William G.; Beezhold, Donald H.; Yen, Hui-Ling; Li, Yuguo; Seto, Wing-Hong; Peiris, Joseph S. M.; Cowling, Benjamin J.

    2016-01-01

    Background The potential for human influenza viruses to spread through fine particle aerosols remains controversial. The objective of our study was to determine whether influenza viruses could be detected in fine particles in hospital rooms. Methods and Findings We sampled the air in 2-bed patient isolation rooms for four hours, placing cyclone samplers at heights of 1.5m and 1.0m. We collected ten air samples each in the presence of at least one patient with confirmed influenza A virus infection, and tested the samples by reverse transcription polymerase chain reaction. We recovered influenza A virus RNA from 5/10 collections (50%); 4/5 were from particles>4 μm, 1/5 from 1–4 μm, and none in particles<1 μm. Conclusions Detection of influenza virus RNA in aerosols at low concentrations in patient rooms suggests that healthcare workers and visitors might have frequent exposure to airborne influenza virus in proximity to infected patients. A limitation of our study was the small sample size. Further studies should be done to quantify the concentration of viable influenza virus in healthcare settings, and factors affecting the detection of influenza viruses in fine particles in the air. PMID:26849130

  20. Saikosaponin A inhibits influenza A virus replication and lung immunopathology.

    PubMed

    Chen, Jianxin; Duan, Mubing; Zhao, Yaqin; Ling, Fangfang; Xiao, Kun; Li, Qian; Li, Bin; Lu, Chunni; Qi, Wenbao; Zeng, Zhenling; Liao, Ming; Liu, Yahong; Chen, Weisan

    2015-12-15

    Fatal influenza outcomes result from a combination of rapid virus replication and collateral lung tissue damage caused by exaggerated pro-inflammatory host immune cell responses. There are few therapeutic agents that target both biological processes for the attenuation of influenza-induced lung pathology. We show that Saikosaponin A, a bioactive triterpene saponin with previouslyestablished anti-inflammatory effects, demonstrates both in vitro and in vivo anti-viral activity against influenza A virus infections. Saikosaponin A attenuated the replication of three different influenza A virus strains, including a highly pathogenic H5N1 strain, in human alveolar epithelial A549 cells. This anti-viral activity occurred through both downregulation of NF-κB signaling and caspase 3-dependent virus ribonucleoprotein nuclear export as demonstrated by NF-κB subunit p65 and influenza virus nucleoprotein nuclear translocation studies in influenza virus infected A549 cells. Critically, Saikosaponin A also attenuated viral replication, aberrant pro-inflammatory cytokine production and lung histopathology in the widely established H1N1 PR8 model of influenza A virus lethality in C57BL/6 mice. Flow cytometry studies of mouse bronchoalveolar lavage cells revealed that SSa exerted immunomodulatory effects through a selective attenuation of lung neutrophil and monocyte recruitment during the early peak of the innate immune response to PR8 infection. Altogether, our results indicate that Saikosaponin A possesses novel therapeutic potential for the treatment of pathological influenza virus infections. PMID:26637810

  1. Quantifying the global antigenic diversity of swine influenza A viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine influenza presents a substantial disease burden for pig populations worldwide and poses a potential pandemic threat to humans. There is considerable diversity in both H1 and H3 influenza viruses circulating in swine due to the frequent introductions of viruses from humans and birds coupled wit...

  2. Experimental Infection of Pigs with the 1918 Pandemic Influenza Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine influenza was first recognized as a disease during the 1918 "Spanish flu" pandemic suggesting the Spanish flu virus caused swine influenza. The objective of this study was to determine the susceptibility of swine to the Spanish flu virus. A plasmid-derived 1918 pandemic H1N1 (1918/rec) influe...

  3. Experimental vaccinations for avian influenza virus including DIVA approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) is a viral disease of poultry that remains an economic threat to commercial poultry throughout the world by negatively impacting animal health and trade. Strategies to control avian influenza (AI) virus are developed to prevent, manage or eradicate the virus from the country, re...

  4. Seasonal trivalent inactivated influenza vaccine protects against 1918 Spanish influenza virus in ferrets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influenza H1N1 pandemic of 1918 was one of the worst medical disasters in human history. Recent studies have demonstrated that the hemagglutinin (HA) protein of the 1918 virus and 2009 H1N1 pandemic virus, the latter now a component of the seasonal trivalent inactivated influenza vaccine (TIV),...

  5. Development of high-yield influenza A virus vaccine viruses.

    PubMed

    Ping, Jihui; Lopes, Tiago J S; Nidom, Chairul A; Ghedin, Elodie; Macken, Catherine A; Fitch, Adam; Imai, Masaki; Maher, Eileen A; Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Vaccination is one of the most cost-effective ways to prevent infection. Influenza vaccines propagated in cultured cells are approved for use in humans, but their yields are often suboptimal. Here, we screened A/Puerto Rico/8/34 (PR8) virus mutant libraries to develop vaccine backbones (defined here as the six viral RNA segments not encoding haemagglutinin and neuraminidase) that support high yield in cell culture. We also tested mutations in the coding and regulatory regions of the virus, and chimeric haemagglutinin and neuraminidase genes. A combination of high-yield mutations from these screens led to a PR8 backbone that improved the titres of H1N1, H3N2, H5N1 and H7N9 vaccine viruses in African green monkey kidney and Madin-Darby canine kidney cells. This PR8 backbone also improves titres in embryonated chicken eggs, a common propagation system for influenza viruses. This PR8 vaccine backbone thus represents an advance in seasonal and pandemic influenza vaccine development. PMID:26334134

  6. Development of high-yield influenza A virus vaccine viruses

    PubMed Central

    Ping, Jihui; Lopes, Tiago J.S.; Nidom, Chairul A.; Ghedin, Elodie; Macken, Catherine A.; Fitch, Adam; Imai, Masaki; Maher, Eileen A.; Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Vaccination is one of the most cost-effective ways to prevent infection. Influenza vaccines propagated in cultured cells are approved for use in humans, but their yields are often suboptimal. Here, we screened A/Puerto Rico/8/34 (PR8) virus mutant libraries to develop vaccine backbones (defined here as the six viral RNA segments not encoding haemagglutinin and neuraminidase) that support high yield in cell culture. We also tested mutations in the coding and regulatory regions of the virus, and chimeric haemagglutinin and neuraminidase genes. A combination of high-yield mutations from these screens led to a PR8 backbone that improved the titres of H1N1, H3N2, H5N1 and H7N9 vaccine viruses in African green monkey kidney and Madin–Darby canine kidney cells. This PR8 backbone also improves titres in embryonated chicken eggs, a common propagation system for influenza viruses. This PR8 vaccine backbone thus represents an advance in seasonal and pandemic influenza vaccine development. PMID:26334134

  7. Predicting Hotspots for Influenza Virus Reassortment

    PubMed Central

    Gilbert, Marius; Martin, Vincent; Cappelle, Julien; Hosseini, Parviez; Njabo, Kevin Y.; Abdel Aziz, Soad; Xiao, Xiangming; Daszak, Peter; Smith, Thomas B.

    2013-01-01

    The 1957 and 1968 influenza pandemics, each of which killed ≈1 million persons, arose through reassortment events. Influenza virus in humans and domestic animals could reassort and cause another pandemic. To identify geographic areas where agricultural production systems are conducive to reassortment, we fitted multivariate regression models to surveillance data on influenza A virus subtype H5N1 among poultry in China and Egypt and subtype H3N2 among humans. We then applied the models across Asia and Egypt to predict where subtype H3N2 from humans and subtype H5N1 from birds overlap; this overlap serves as a proxy for co-infection and in vivo reassortment. For Asia, we refined the prioritization by identifying areas that also have high swine density. Potential geographic foci of reassortment include the northern plains of India, coastal and central provinces of China, the western Korean Peninsula and southwestern Japan in Asia, and the Nile Delta in Egypt. PMID:23628436

  8. Ecology of avian influenza virus in birds.

    PubMed

    Causey, Douglas; Edwards, Scott V

    2008-02-15

    Avian influenza A virus (an orthomyxovirus) is a zoonotic pathogen with a natural reservoir entirely in birds. The influenza virus genome is an 8-segment single-stranded RNA with high potential for in situ recombination. Two segments code for the hemagglutinin (H) and neuraminidase (N) antigens used for host-cell entry. At present, 16 H and 9 N subtypes are known, for a total of 144 possible different influenza subtypes, each with potentially different host susceptibility. With >10,000 species of birds found in nearly every terrestrial and aquatic habitat, there are few places on earth where birds cannot be found. The avian immune system differs from that of humans in several important features, including asynchronous B and T lymphocyte systems and a polymorphic multigene immune complex, but little is known about the immunogenetics of pathogenic response. Postbreeding dispersal and migration and a naturally high degree of environmental vagility mean that wild birds have the potential to be vectors that transmit highly pathogenic variants great distances from the original sources of infection. PMID:18269325

  9. Evaluation of Alere i Influenza A&B for rapid detection of influenza viruses A and B.

    PubMed

    Nie, Shuping; Roth, Richard B; Stiles, Jeffrey; Mikhlina, Albina; Lu, Xuedong; Tang, Yi-Wei; Babady, N Esther

    2014-09-01

    Rapid and accurate diagnosis of influenza is important for infection control, as well as for patient management. Alere i Influenza A&B is an isothermal nucleic acid amplification-based integrated system for detection and differentiation of influenza virus A and influenza virus B. The performance of the Alere i Influenza A&B was screened using frozen nasopharyngeal-swab specimens collected in viral transport medium (VTM) that were originally tested fresh with the FilmArray Respiratory Panel (RP) assay during the 2012-2013 influenza outbreak. In total, 360 VTM specimens were selected for Alere i Influenza A&B testing: 40 influenza virus A H1N1-2009 (influenza virus A-1), 40 influenza virus A H3N2 (influenza virus A-3), 37 influenza virus A "equivocal" or "no subtype detected" (influenza virus A-u), 41 influenza virus B, and 202 influenza virus-negative specimens, as initially determined by the FilmArray RP assay. The Alere assay showed sensitivities of 87.2%, 92.5%, 25.0%, and 97.4% for influenza virus A-1, influenza virus A-3, influenza virus A-u, and influenza virus B, respectively, after discordant resolution by Prodesse ProFLU+ PCR. The specificities were 100% for both influenza virus A and influenza virus B. In general, the Alere i Influenza A&B provided good sensitivity, although the assay did show poorer sensitivity with samples determined to have low influenza virus A titers by Prodesse ProFlu+ PCR (a mean real-time PCR threshold cycle [CT] value of 31.9 ± 2.0), which included the majority of the samples called influenza virus A "equivocal" or "no subtype detected" by a single BioFire FilmArray RP test. The integrated, rapid, and simple characteristics of the Alere i Influenza A&B assay make it a potential candidate for point-of-care testing, with a test turnaround time of less than 15 min. PMID:24989611

  10. The contrasting phylodynamics of human influenza B viruses.

    PubMed

    Vijaykrishna, Dhanasekaran; Holmes, Edward C; Joseph, Udayan; Fourment, Mathieu; Su, Yvonne C F; Halpin, Rebecca; Lee, Raphael T C; Deng, Yi-Mo; Gunalan, Vithiagaran; Lin, Xudong; Stockwell, Timothy B; Fedorova, Nadia B; Zhou, Bin; Spirason, Natalie; Kühnert, Denise; Bošková, Veronika; Stadler, Tanja; Costa, Anna-Maria; Dwyer, Dominic E; Huang, Q Sue; Jennings, Lance C; Rawlinson, William; Sullivan, Sheena G; Hurt, Aeron C; Maurer-Stroh, Sebastian; Wentworth, David E; Smith, Gavin J D; Barr, Ian G

    2015-01-01

    A complex interplay of viral, host, and ecological factors shapes the spatio-temporal incidence and evolution of human influenza viruses. Although considerable attention has been paid to influenza A viruses, a lack of equivalent data means that an integrated evolutionary and epidemiological framework has until now not been available for influenza B viruses, despite their significant disease burden. Through the analysis of over 900 full genomes from an epidemiological collection of more than 26,000 strains from Australia and New Zealand, we reveal fundamental differences in the phylodynamics of the two co-circulating lineages of influenza B virus (Victoria and Yamagata), showing that their individual dynamics are determined by a complex relationship between virus transmission, age of infection, and receptor binding preference. In sum, this work identifies new factors that are important determinants of influenza B evolution and epidemiology. PMID:25594904

  11. The contrasting phylodynamics of human influenza B viruses

    PubMed Central

    Vijaykrishna, Dhanasekaran; Holmes, Edward C; Joseph, Udayan; Fourment, Mathieu; Su, Yvonne CF; Halpin, Rebecca; Lee, Raphael TC; Deng, Yi-Mo; Gunalan, Vithiagaran; Lin, Xudong; Stockwell, Timothy B; Fedorova, Nadia B; Zhou, Bin; Spirason, Natalie; Kühnert, Denise; Bošková, Veronika; Stadler, Tanja; Costa, Anna-Maria; Dwyer, Dominic E; Huang, Q Sue; Jennings, Lance C; Rawlinson, William; Sullivan, Sheena G; Hurt, Aeron C; Maurer-Stroh, Sebastian; Wentworth, David E; Smith, Gavin JD; Barr, Ian G

    2015-01-01

    A complex interplay of viral, host, and ecological factors shapes the spatio-temporal incidence and evolution of human influenza viruses. Although considerable attention has been paid to influenza A viruses, a lack of equivalent data means that an integrated evolutionary and epidemiological framework has until now not been available for influenza B viruses, despite their significant disease burden. Through the analysis of over 900 full genomes from an epidemiological collection of more than 26,000 strains from Australia and New Zealand, we reveal fundamental differences in the phylodynamics of the two co-circulating lineages of influenza B virus (Victoria and Yamagata), showing that their individual dynamics are determined by a complex relationship between virus transmission, age of infection, and receptor binding preference. In sum, this work identifies new factors that are important determinants of influenza B evolution and epidemiology. DOI: http://dx.doi.org/10.7554/eLife.05055.001 PMID:25594904

  12. Dynamical correlations in the escape strategy of Influenza A virus

    NASA Astrophysics Data System (ADS)

    Taggi, L.; Colaiori, F.; Loreto, V.; Tria, F.

    2013-03-01

    The evolutionary dynamics of human Influenza A virus presents a challenging theoretical problem. An extremely high mutation rate allows the virus to escape, at each epidemic season, the host immune protection elicited by previous infections. At the same time, at each given epidemic season a single quasi-species, that is a set of closely related strains, is observed. A non-trivial relation between the genetic (i.e., at the sequence level) and the antigenic (i.e., related to the host immune response) distances can shed light into this puzzle. In this paper we introduce a model in which, in accordance with experimental observations, a simple interaction rule based on spatial correlations among point mutations dynamically defines an immunity space in the space of sequences. We investigate the static and dynamic structure of this space and we discuss how it affects the dynamics of the virus-host interaction. Interestingly we observe a staggered time structure in the virus evolution as in the real Influenza evolutionary dynamics.

  13. Research update on avian influenza viruses and H1N1 influenza virus in poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) remains an economic threat to commercial poultry throughout the world by negatively impacting animal health and trade. Southeast Poultry Research Laboratory conducts research on many areas related to AI including pathogenesis and transmission studies, use of vaccination, virus ...

  14. Verdinexor, a Novel Selective Inhibitor of Nuclear Export, Reduces Influenza A Virus Replication In Vitro and In Vivo

    PubMed Central

    Perwitasari, Olivia; Johnson, Scott; Yan, Xiuzhen; Howerth, Elizabeth; Shacham, Sharon; Landesman, Yosef; Baloglu, Erkan; McCauley, Dilara; Tamir, Sharon; Tompkins, S. Mark

    2014-01-01

    ABSTRACT Influenza is a global health concern, causing death, morbidity, and economic losses. Chemotherapeutics that target influenza virus are available; however, rapid emergence of drug-resistant strains is common. Therapeutic targeting of host proteins hijacked by influenza virus to facilitate replication is an antiviral strategy to reduce the development of drug resistance. Nuclear export of influenza virus ribonucleoprotein (vRNP) from infected cells has been shown to be mediated by exportin 1 (XPO1) interaction with viral nuclear export protein tethered to vRNP. RNA interference screening has identified XPO1 as a host proinfluenza factor where XPO1 silencing results in reduced influenza virus replication. The Streptomyces metabolite XPO1 inhibitor leptomycin B (LMB) has been shown to limit influenza virus replication in vitro; however, LMB is toxic in vivo, which makes it unsuitable for therapeutic use. In this study, we tested the anti-influenza virus activity of a new class of orally available small-molecule selective inhibitors of nuclear export, specifically, the XPO1 antagonist KPT-335 (verdinexor). Verdinexor was shown to potently and selectively inhibit vRNP export and effectively inhibited the replication of various influenza virus A and B strains in vitro, including pandemic H1N1 virus, highly pathogenic H5N1 avian influenza virus, and the recently emerged H7N9 strain. In vivo, prophylactic and therapeutic administration of verdinexor protected mice against disease pathology following a challenge with influenza virus A/California/04/09 or A/Philippines/2/82-X79, as well as reduced lung viral loads and proinflammatory cytokine expression, while having minimal toxicity. These studies show that verdinexor acts as a novel anti-influenza virus therapeutic agent. IMPORTANCE Antiviral drugs represent important means of influenza virus control. However, substantial resistance to currently approved influenza therapeutic drugs has developed. New antiviral

  15. Pandemic Threat Posed by Avian Influenza A Viruses

    PubMed Central

    Horimoto, Taisuke; Kawaoka, Yoshihiro

    2001-01-01

    Influenza pandemics, defined as global outbreaks of the disease due to viruses with new antigenic subtypes, have exacted high death tolls from human populations. The last two pandemics were caused by hybrid viruses, or reassortants, that harbored a combination of avian and human viral genes. Avian influenza viruses are therefore key contributors to the emergence of human influenza pandemics. In 1997, an H5N1 influenza virus was directly transmitted from birds in live poultry markets in Hong Kong to humans. Eighteen people were infected in this outbreak, six of whom died. This avian virus exhibited high virulence in both avian and mammalian species, causing systemic infection in both chickens and mice. Subsequently, another avian virus with the H9N2 subtype was directly transmitted from birds to humans in Hong Kong. Interestingly, the genes encoding the internal proteins of the H9N2 virus are genetically highly related to those of the H5N1 virus, suggesting a unique property of these gene products. The identification of avian viruses in humans underscores the potential of these and similar strains to produce devastating influenza outbreaks in major population centers. Although highly pathogenic avian influenza viruses had been identified before the 1997 outbreak in Hong Kong, their devastating effects had been confined to poultry. With the Hong Kong outbreak, it became clear that the virulence potential of these viruses extended to humans. PMID:11148006

  16. The Mutational Robustness of Influenza A Virus.

    PubMed

    Visher, Elisa; Whitefield, Shawn E; McCrone, John T; Fitzsimmons, William; Lauring, Adam S

    2016-08-01

    A virus' mutational robustness is described in terms of the strength and distribution of the mutational fitness effects, or MFE. The distribution of MFE is central to many questions in evolutionary theory and is a key parameter in models of molecular evolution. Here we define the mutational fitness effects in influenza A virus by generating 128 viruses, each with a single nucleotide mutation. In contrast to mutational scanning approaches, this strategy allowed us to unambiguously assign fitness values to individual mutations. The presence of each desired mutation and the absence of additional mutations were verified by next generation sequencing of each stock. A mutation was considered lethal only after we failed to rescue virus in three independent transfections. We measured the fitness of each viable mutant relative to the wild type by quantitative RT-PCR following direct competition on A549 cells. We found that 31.6% of the mutations in the genome-wide dataset were lethal and that the lethal fraction did not differ appreciably between the HA- and NA-encoding segments and the rest of the genome. Of the viable mutants, the fitness mean and standard deviation were 0.80 and 0.22 in the genome-wide dataset and best modeled as a beta distribution. The fitness impact of mutation was marginally lower in the segments coding for HA and NA (0.88 ± 0.16) than in the other 6 segments (0.78 ± 0.24), and their respective beta distributions had slightly different shape parameters. The results for influenza A virus are remarkably similar to our own analysis of CirSeq-derived fitness values from poliovirus and previously published data from other small, single stranded DNA and RNA viruses. These data suggest that genome size, and not nucleic acid type or mode of replication, is the main determinant of viral mutational fitness effects. PMID:27571422

  17. Inhibitors of influenza viruses replication: a patent evaluation (WO2013019828).

    PubMed

    Xie, Yuanchao; Song, Weiguo; Xiao, Weidong; Gu, Changjuan; Xu, Wenfang

    2013-11-01

    A series of compounds incorporating two aromatic heterocycles were prepared as inhibitors of influenza virus replication in the patent. Some of them presented potent activity against influenza virus in Madin-Darby canine kidney (MDCK) cells and in influenza therapeutic mouse model. These compounds in the patent were also defined to be pharmaceutically acceptable salts and pharmaceutical compositions that were claimed to be useful for treating influenza. In view of the threat of influenza pandemic, it is necessary to discover new anti-influenza drugs. Although there is a lack of essential biological data and the molecular mechanisms are not clear, these compounds with potent antiviral activity stand for a new type of anti-influenza agents and deserve further studies. PMID:23967861

  18. Increased influenza pneumonia mortality of mice adoptively immunized with node and spleen cells sensitized by inactivated but not live virus.

    PubMed Central

    Cate, T R; Mold, N G

    1975-01-01

    Syngeneic mice adoptively immunized intravenously with 25 million washed node and spleen cells from donors vaccinated subcutaneously with formolized influenza A PR8 had a higher mortality with influenza pneumonia after challenge with homologous virus than occurred in recipients of similar cells from unsensitized donors, and this increased mortality was prevented by treatment of the sensitized cells with antithymocyte serum. Mice adoptively immunized with cells from donors vaccinated with formolized influenza A PR8 also had a higher mortality than recipients of unsensitized cells after challenge with heterologous influenza B Lee. Mice who received PR8-sensitized cells and survived challenge with influenza B Lee developed antibody only to the challenge virus, and serum antibody titers to the challenge virus in surviving recipients of sensitized cells were similar to those of recipients of unsensitized cells in all studies. Influenza mortality of recipients of antibody-containing mouse serum after homologous virus challenge was similar to that of recipients of antibody-free mouse serum in this model. Washed node and spleen cells from donor mice who had survived respiratory infection or received subcutaneous vaccination with live influenza A PR8 and those from donor mice given typhoid vaccine subcutaneously all failed to alter mortality from that observed in recipients of unsensitized cells after challenge with influenza A PR8. These results suggest that subcutaneous vaccination with inactivated influenza establishes a reactivity of the cell-mediated immunologic system which can increase the severity of influenza infection of the respiratory tract under certain conditions, and that sensitization by live influenza fails to produce this effect. PMID:47313

  19. Sialic acid tissue distribution and influenza virus tropism

    PubMed Central

    Kumlin, Urban; Olofsson, Sigvard; Dimock, Ken; Arnberg, Niklas

    2008-01-01

    Abstract  Avian influenza A viruses exhibit a strong preference for using α2,3‐linked sialic acid as a receptor. Until recently, the presumed lack of this receptor in human airways was believed to constitute an efficient barrier to avian influenza A virus infection of humans. Recent zoonotic outbreaks of avian influenza A virus have triggered researchers to analyse tissue distribution of sialic acid in further detail. Here, we review and extend the current knowledge about sialic acid distribution in human tissues, and discuss viruses with ocular tropism and their preference for α2,3‐linked sialic acid. PMID:19453419

  20. Modeling Influenza Virus Infection: A Roadmap for Influenza Research

    PubMed Central

    Boianelli, Alessandro; Nguyen, Van Kinh; Ebensen, Thomas; Schulze, Kai; Wilk, Esther; Sharma, Niharika; Stegemann-Koniszewski, Sabine; Bruder, Dunja; Toapanta, Franklin R.; Guzmán, Carlos A.; Meyer-Hermann, Michael; Hernandez-Vargas, Esteban A.

    2015-01-01

    Influenza A virus (IAV) infection represents a global threat causing seasonal outbreaks and pandemics. Additionally, secondary bacterial infections, caused mainly by Streptococcus pneumoniae, are one of the main complications and responsible for the enhanced morbidity and mortality associated with IAV infections. In spite of the significant advances in our knowledge of IAV infections, holistic comprehension of the interplay between IAV and the host immune response (IR) remains largely fragmented. During the last decade, mathematical modeling has been instrumental to explain and quantify IAV dynamics. In this paper, we review not only the state of the art of mathematical models of IAV infection but also the methodologies exploited for parameter estimation. We focus on the adaptive IR control of IAV infection and the possible mechanisms that could promote a secondary bacterial coinfection. To exemplify IAV dynamics and identifiability issues, a mathematical model to explain the interactions between adaptive IR and IAV infection is considered. Furthermore, in this paper we propose a roadmap for future influenza research. The development of a mathematical modeling framework with a secondary bacterial coinfection, immunosenescence, host genetic factors and responsiveness to vaccination will be pivotal to advance IAV infection understanding and treatment optimization. PMID:26473911

  1. Sterilizing immunity to influenza virus infection requires local antigen-specific T cell response in the lungs

    PubMed Central

    Dutta, Avijit; Huang, Ching-Tai; Lin, Chun-Yen; Chen, Tse-Ching; Lin, Yung-Chang; Chang, Chia-Shiang; He, Yueh-Chia

    2016-01-01

    Sterilizing immunity is a unique immune status, which prevents effective virus infection into the host. It is different from the immunity that allows infection but with subsequent successful eradication of the virus. Pre-infection induces sterilizing immunity to homologous influenza virus challenge in ferret. In our antigen-specific experimental system, mice pre-infected with PR8 influenza virus through nasal route are likewise resistant to reinfection of the same strain of virus. The virus is cleared before establishment of effective infection. Intramuscular influenza virus injection confers protection against re-infection with facilitated virus clearance but not sterilizing immunity. Pre-infection and intramuscular injection generates comparable innate immunity and antibody response, but only pre-infection induces virus receptor reduction and efficient antigen-specific T cell response in the lungs. Pre-infection with nH1N1 influenza virus induces virus receptor reduction but not PR8-specific T cell immune response in the lungs and cannot prevent infection of PR8 influenza virus. Pre-infection with PR8 virus induced PR8-specific T cell response in the lungs but cannot prevent infection of nH1N1 virus either. These results reveal that antigen-specific T cell immunity is required for sterilizing immunity. PMID:27596047

  2. Sterilizing immunity to influenza virus infection requires local antigen-specific T cell response in the lungs.

    PubMed

    Dutta, Avijit; Huang, Ching-Tai; Lin, Chun-Yen; Chen, Tse-Ching; Lin, Yung-Chang; Chang, Chia-Shiang; He, Yueh-Chia

    2016-01-01

    Sterilizing immunity is a unique immune status, which prevents effective virus infection into the host. It is different from the immunity that allows infection but with subsequent successful eradication of the virus. Pre-infection induces sterilizing immunity to homologous influenza virus challenge in ferret. In our antigen-specific experimental system, mice pre-infected with PR8 influenza virus through nasal route are likewise resistant to reinfection of the same strain of virus. The virus is cleared before establishment of effective infection. Intramuscular influenza virus injection confers protection against re-infection with facilitated virus clearance but not sterilizing immunity. Pre-infection and intramuscular injection generates comparable innate immunity and antibody response, but only pre-infection induces virus receptor reduction and efficient antigen-specific T cell response in the lungs. Pre-infection with nH1N1 influenza virus induces virus receptor reduction but not PR8-specific T cell immune response in the lungs and cannot prevent infection of PR8 influenza virus. Pre-infection with PR8 virus induced PR8-specific T cell response in the lungs but cannot prevent infection of nH1N1 virus either. These results reveal that antigen-specific T cell immunity is required for sterilizing immunity. PMID:27596047

  3. Current Approaches for Diagnosis of Influenza Virus Infections in Humans

    PubMed Central

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-01-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000–50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans. PMID:27077877

  4. Development of Framework for Assessing Influenza Virus Pandemic Risk

    PubMed Central

    Burke, Stephen A.; Cox, Nancy J.

    2015-01-01

    Although predicting which influenza virus subtype will cause the next pandemic is not yet possible, public health authorities must continually assess the pandemic risk associated with animal influenza viruses, particularly those that have caused infections in humans, and determine what resources should be dedicated to mitigating that risk. To accomplish this goal, a risk assessment framework was created in collaboration with an international group of influenza experts. Compared with the previously used approach, this framework, named the Influenza Risk Assessment Tool, provides a systematic and transparent approach for assessing and comparing threats posed primarily by avian and swine influenza viruses. This tool will be useful to the international influenza community and will remain flexible and responsive to changing information. PMID:26196098

  5. Current Approaches for Diagnosis of Influenza Virus Infections in Humans.

    PubMed

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-04-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000-50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans. PMID:27077877

  6. A zanamivir dimer with prophylactic and enhanced therapeutic activity against influenza viruses

    PubMed Central

    Tarbet, E. Bart; Hamilton, Stephanie; Vollmer, Almut H.; Luttick, Angela; Ng, Wy Ching; Pryor, Melinda; Hurst, Brett L.; Crawford, Simon; Smee, Donald F.; Tucker, Simon P.

    2014-01-01

    Objectives Emerging drug resistance to antiviral therapies is an increasing challenge for the treatment of influenza virus infections. One new antiviral compound, BTA938, a dimeric derivative of the viral neuraminidase inhibitor zanamivir, contains a 14-carbon linker bridging two zanamivir moieties. In these studies, we evaluated antiviral efficacy in cell cultures infected with influenza virus and in mouse models of lethal influenza using H1N1pdm09, H3N2 and oseltamivir-resistant (H275Y) viruses. Methods In vitro activity was evaluated against 22 strains of influenza virus. Additionally, in vivo studies compared the efficacy of BTA938 or zanamivir after intranasal treatment. We also tested the hypothesis of a dual mode of action for BTA938 using scanning electron microscopy (SEM). Results BTA938 inhibited the viruses at nanomolar concentrations in vitro with a median 50% effective concentration value of 0.5 nM. In mouse models, the dimer provided ∼10-fold greater protection than zanamivir. The data also showed that a single low dose (3 mg/kg) protected 100% of mice from an otherwise lethal oseltamivir-resistant (H275Y) influenza virus infection. Remarkably, a single prophylactic treatment (10 mg/kg) administered 7 days before the challenge protected 70% of mice and when administered 1 or 3 days before the challenge it protected 90% of mice. Additionally, SEM provides evidence that the increased antiviral potency may be mediated by an enhanced aggregation of virus on the cell surface. Conclusions In vitro and in vivo experiments showed the high antiviral activity of BTA938 for the treatment of influenza virus infections. Moreover, we demonstrated that a single dose of BTA938 is sufficient for prophylactic and therapeutic protection in mouse models. PMID:24777908

  7. Protection Against H7 Subtype Influenza Virus Infection in Mice by Passive Transfer of Neutralizing Monoclonal Antibody.

    PubMed

    Zhang, Zhuo; Liu, Ming; Zheng, Shimin

    2015-10-01

    H7 subtype influenza viruses pose serious threats to both the poultry industry and public health. Recent human infections of avian H7N9 influenza viruses with substantial morbidity and mortality have raised concerns about this virus becoming a potential pandemic pathogen. Neutralizing antibodies have been proven to be highly effective in blocking influenza virus infections. In this study, in order to develop an antibody-based immunoprophylaxis against H7 subtype influenza virus, we first generated a neutralizing monoclonal antibody (MAb) by using a pseudotyped lentiviral vector carrying the hemagglutinin protein of H7 subtype influenza virus. In vitro studies demonstrated that this neutralizing MAb completely inhibited the infection of an H7 subtype influenza virus to cells. The protective efficacy of this MAb was then further tested in a mouse model. It was shown that passive immunization of this MAb protected mice from local virus challenge. Results of the current study lay a foundation for the development of neutralizing MAb-mediated prophylactic strategies to combat human H7 influenza virus infections. PMID:26492625

  8. An MDCK Cell Culture-Derived Formalin-Inactivated Influenza Virus Whole-Virion Vaccine from an Influenza Virus Library Confers Cross-Protective Immunity by Intranasal Administration in Mice

    PubMed Central

    Haredy, Ahmad M.; Takenaka, Nobuyuki; Yamada, Hiroshi; Sakoda, Yoshihiro; Okamatsu, Masatoshi; Yamamoto, Naoki; Omasa, Takeshi; Ohtake, Hisao; Mori, Yasuko; Kida, Hiroshi; Yamanishi, Koichi

    2013-01-01

    It is currently impossible to predict the next pandemic influenza virus strain. We have thus established a library of influenza viruses of all hemagglutinin and neuraminidase subtypes and their genes. In this article, we examine the applicability of a rapid production model for the preparation of vaccines against emerging pandemic influenza viruses. This procedure utilizes the influenza virus library, cell culture-based vaccine production, and intranasal administration to induce a cross-protective immune response. First, an influenza virus reassortant from the library, A/duck/Hokkaido/Vac-3/2007 (H5N1), was passaged 22 times (P22) in Madin-Darby canine kidney (MDCK) cells. The P22 virus had a titer of >2 ×108 PFU/ml, which was 40 times that of the original strain, with 4 point mutations, which altered amino acids in the deduced protein sequences encoded by the PB2 and PA genes. We then produced a formalin-inactivated whole-virion vaccine from the MDCK cell-cultured A/duck/Hokkaido/Vac-3/2007 (H5N1) P22 virus. Intranasal immunization of mice with this vaccine protected them against challenges with lethal influenza viruses of homologous and heterologous subtypes. We further demonstrated that intranasal immunization with the vaccine induced cross-reactive neutralizing antibody responses against the homotypic H5N1 influenza virus and its antigenic variants and cross-reactive cell-mediated immune responses to the homologous virus, its variants within a subtype, and even an influenza virus of a different subtype. These results indicate that a rapid model for emergency vaccine production may be effective for producing the next generation of pandemic influenza virus vaccines. PMID:23637045

  9. A genetically adjuvanted influenza B virus vector increases immunogenicity and protective efficacy in mice.

    PubMed

    Kittel, Christian; Wressnigg, Nina; Shurygina, Anna Polina; Wolschek, Markus; Stukova, Marina; Romanovskaya-Romanko, Ekatherina; Romanova, Julia; Kiselev, Oleg; Muster, Thomas; Egorov, Andrej

    2015-10-01

    The existence of multiple antigenically distinct types and subtypes of influenza viruses allows the construction of a multivalent vector system for the mucosal delivery of foreign sequences. Influenza A viruses have been exploited successfully for the expression of extraneous antigens as well as immunostimulatory molecules. In this study, we describe the development of an influenza B virus vector whose functional part of the interferon antagonist NS1 was replaced by human interleukin 2 (IL2) as a genetic adjuvant. We demonstrate that IL2 expressed by this viral vector displays immune adjuvant activity in immunized mice. Animals vaccinated with the IL2 viral vector showed an increased hemagglutination inhibition antibody response and higher protective efficacy after challenge with a wild-type influenza B virus when compared to mice vaccinated with a control virus. Our results demonstrate that it is feasible to construct influenza B vaccine strains expressing immune-potentiating foreign sequences from the NS genomic segment. Based on these data, it is now hypothetically possible to create a trivalent (or quadrivalent) live attenuated influenza vaccine in which each component expresses a selected genetic adjuvant with tailored expression levels. PMID:26215439

  10. Influenza Virus Aerosols in the Air and Their Infectiousness

    PubMed Central

    2014-01-01

    Influenza is one of the most contagious and rapidly spreading infectious diseases and an important global cause of hospital admissions and mortality. There are some amounts of the virus in the air constantly. These amounts is generally not enough to cause disease in people, due to infection prevention by healthy immune systems. However, at a higher concentration of the airborne virus, the risk of human infection increases dramatically. Early detection of the threshold virus concentration is essential for prevention of the spread of influenza infection. This review discusses different approaches for measuring the amount of influenza A virus particles in the air and assessing their infectiousness. Here we also discuss the data describing the relationship between the influenza virus subtypes and virus air transmission, and distribution of viral particles in aerosol drops of different sizes. PMID:25197278