| genetic characterization of h1n2 swine influenza virus isolated in china and its pathogenesis and inflammatory responses in mice. | in 2009, two h1n2 influenza viruses were isolated from trachea swabs of pigs in hubei in china. we compared these sequences with the other 18 complete genome sequences of swine h1n2 isolates from china during 2004 to 2010 and undertook extensive analysis of their evolutionary patterns. six different genotypes - two reassortants between triple reassortant (tr) h3n2 and classical swine (cs) h1n1 virus, three reassortants between tr h1n2, eurasian avian-like h1n1 swine virus and h9n2 swine virus, a ... | 2013 | 23591972 |
| immunomodulaton and attenuation of lethal influenza a virus infection by oral administration with kiom-c. | herbal medicine is used to treat many conditions such as asthma, eczema, premenstrual syndrome, rheumatoid arthritis, migraine, headaches, menopausal symptoms, chronic fatigue, irritable bowel syndrome, cancer, and viral infections such as influenza. in this study, we investigated the antiviral effect of kiom-c for the treatment of influenza a virus infection. our results show that oral administration of kiom-c conferred a survival benefit to mice infected with the 2009 pandemic h1n1 [a(h1n1)pdm ... | 2013 | 23588232 |
| antigenic variation of h1n1, h1n2 and h3n2 swine influenza viruses in japan and vietnam. | the antigenicity of the influenza a virus hemagglutinin is responsible for vaccine efficacy in protecting pigs against swine influenza virus (siv) infection. however, the antigenicity of siv strains currently circulating in japan and vietnam has not been well characterized. we examined the antigenicity of classical h1 sivs, pandemic a(h1n1)2009 (a(h1n1)pdm09) viruses, and seasonal human-lineage sivs isolated in japan and vietnam. a hemagglutination inhibition (hi) assay was used to determine ant ... | 2013 | 23435952 |
| infection of the upper respiratory tract with seasonal influenza a(h3n2) virus induces protective immunity in ferrets against infection with a(h1n1)pdm09 virus after intranasal, but not intratracheal, inoculation. | the clinical symptoms caused by infection with influenza a virus vary widely and depend on the strain causing the infection, the dose and route of inoculation, and the presence of preexisting immunity. in most cases, seasonal influenza a viruses cause relatively mild upper respiratory tract disease, while sometimes patients develop an acute severe pneumonia. heterosubtypic immunity induced by previous infections with influenza a viruses may dampen the development of clinical symptoms caused by i ... | 2013 | 23365444 |
| pandemic influenza a h1n1 in swine and other animals. | influenza a virus infection has been reported in a variety of mammalian and avian species. wild waterfowl such as ducks and geese are considered the principal reservoir of many influenza a viruses. on may 2, 2009, the first confirmed case of pandemic 2009 h1n1 (ph1n1) in animals was reported in a small swine herd in canada. a public health investigation concluded that transmission from people to pigs was the likely source of infection. subsequently the ph1n1 virus has been reported in turkeys, c ... | 2013 | 23254339 |
| cloned defective interfering influenza virus protects ferrets from pandemic 2009 influenza a virus and allows protective immunity to be established. | influenza a viruses are a major cause of morbidity and mortality in the human population, causing epidemics in the winter, and occasional worldwide pandemics. in addition there are periodic outbreaks in domestic poultry, horses, pigs, dogs, and cats. infections of domestic birds can be fatal for the birds and their human contacts. control in man operates through vaccines and antivirals, but both have their limitations. in the search for an alternative treatment we have focussed on defective inte ... | 2012 | 23251341 |
| immunogenic and protective properties of the first kazakhstan vaccine against pandemic influenza a (h1n1) pdm09 in ferrets. | this paper presents the results of a pre-clinical study of the immunogenicity and efficacy of an egg-derived, inactivated, whole-virion adjuvanted vaccine (refluvac®) on ferret models. for this purpose, groups of eight ferrets (6 to 7 months old) were injected with 0.5 ml of vaccine specimens containing 3.75, 7.5 or 15.0 μg of virus hemagglutinin. administration was intramuscular and given either as a single dose or as two doses 14 days apart. all vaccine specimens manifested immunogenicity in f ... | 2012 | 23180289 |
| characterization of the 2009 pandemic a/beijing/501/2009 h1n1 influenza strain in human airway epithelial cells and ferrets. | a novel 2009 swine-origin influenza a h1n1 virus (s-oiv h1n1) has been transmitted among humans worldwide. however, the pathogenesis of this virus in human airway epithelial cells and mammals is not well understood. | 2012 | 23049974 |
| comparison of the protection of ferrets against pandemic 2009 influenza a virus (h1n1) by 244 di influenza virus and oseltamivir. | the main antivirals employed to combat seasonal and pandemic influenza are oseltamivir and zanamivir which act by inhibiting the virus-encoded neuraminidase. these have to be deployed close to the time of infection and antiviral resistance to the more widely used oseltamivir has arisen relatively rapidly. defective interfering (di) influenza virus is a natural antiviral that works in a different way to oseltamivir and zanamivir, and a cloned version (segment 1 244 di rna in a cloned a/pr/8/34 vi ... | 2012 | 23041142 |
| virulence and transmissibility of h1n2 influenza virus in ferrets imply the continuing threat of triple-reassortant swine viruses. | efficient worldwide swine surveillance for influenza a viruses is urgently needed; the emergence of a novel reassortant pandemic h1n1 (ph1n1) virus in 2009 demonstrated that swine can be the direct source of pandemic influenza and that the pandemic potential of viruses prevalent in swine populations must be monitored. we used the ferret model to assess the pathogenicity and transmissibility of predominant korean triple-reassortant swine (trsw) h1n2 and h3n2 influenza viruses genetically related ... | 2012 | 23019374 |
| flagellin-ha vaccines protect ferrets and mice against h5n1 highly pathogenic avian influenza virus (hpaiv) infections. | in order to meet the global demand for rapid production of pandemic influenza vaccines, we have developed a recombinant fusion vaccine platform in which the globular head of hemagglutinin (ha) antigen is genetically fused to bacterial flagellin (a tlr5 ligand). these flagellin-ha fusion vaccine candidates elicit highly protective immunity against a lethal challenge with 2009 pandemic h1n1 (liu, et al. plos one 2011; 6:e20928) or h5n1 influenza a/vietnam/1203/04 (a/vn) infections in mice (song, e ... | 2012 | 23000130 |
| comparison of temporal and spatial dynamics of seasonal h3n2, pandemic h1n1 and highly pathogenic avian influenza h5n1 virus infections in ferrets. | humans may be infected by different influenza a viruses--seasonal, pandemic, and zoonotic--which differ in presentation from mild upper respiratory tract disease to severe and sometimes fatal pneumonia with extra-respiratory spread. differences in spatial and temporal dynamics of these infections are poorly understood. therefore, we inoculated ferrets with seasonal h3n2, pandemic h1n1 (ph1n1), and highly pathogenic avian h5n1 influenza virus and performed detailed virological and pathological an ... | 2012 | 22905124 |
| host gene expression signatures discriminate between ferrets infected with genetically similar h1n1 strains. | different respiratory viruses induce virus-specific gene expression in the host. recent evidence, including those presented here, suggests that genetically related isolates of influenza virus induce strain-specific host gene regulation in several animal models. here, we identified systemic strain-specific gene expression signatures in ferrets infected with pandemic influenza a/california/07/2009, a/mexico/4482/2009 or seasonal influenza a/brisbane/59/2007. using uncorrelated shrunken centroid cl ... | 2012 | 22808249 |
| key molecular factors in hemagglutinin and pb2 contribute to efficient transmission of the 2009 h1n1 pandemic influenza virus. | animal influenza viruses pose a clear threat to public health. transmissibility among humans is a prerequisite for a novel influenza virus to cause a human pandemic. a novel reassortant swine influenza virus acquired sustained human-to-human transmissibility and caused the 2009 influenza pandemic. however, the molecular aspects of influenza virus transmission remain poorly understood. here, we show that an amino acid in hemagglutinin (ha) is important for the 2009 h1n1 influenza pandemic virus ( ... | 2012 | 22740390 |
| experimental adaptation of an influenza h5 ha confers respiratory droplet transmission to a reassortant h5 ha/h1n1 virus in ferrets. | highly pathogenic avian h5n1 influenza a viruses occasionally infect humans, but currently do not transmit efficiently among humans. the viral haemagglutinin (ha) protein is a known host-range determinant as it mediates virus binding to host-specific cellular receptors. here we assess the molecular changes in ha that would allow a virus possessing subtype h5 ha to be transmissible among mammals. we identified a reassortant h5 ha/h1n1 virus-comprising h5 ha (from an h5n1 virus) with four mutation ... | 2012 | 22722205 |
| characterization in vitro and in vivo of pandemic (h1n1) 2009 influenza viruses isolated from patients. | the first influenza pandemic of the 21st century was caused by novel h1n1 viruses that emerged in early 2009. molecular evolutionary analyses of the 2009 pandemic influenza a h1n1 [a(h1n1)pdm09] virus revealed two major clusters, cluster i and cluster ii. although the pathogenicity of viruses belonging to cluster i, which became extinct by the end of 2009, has been examined in a nonhuman primate model, the pathogenic potential of viruses belonging to cluster ii, which has spread more widely in t ... | 2012 | 22718834 |
| concurrent 2009 pandemic influenza a (h1n1) virus infection in ferrets and in a community in pennsylvania. | we report a fall 2010 cluster of pandemic influenza a/h1n1 (ph1n1) infections in pet ferrets in lehigh valley region of pennsylvania. the ferrets were associated with one pet shop. the influenza cluster occurred during a period when the existing human surveillance systems had identified little to no ph1n1 in humans in the lehigh valley, and there were no routine influenza surveillance systems for exotic pets. the index case was a 2.5-month-old neutered male ferret that was presented to a veterin ... | 2013 | 22697485 |
| effect of priming with h1n1 influenza viruses of variable antigenic distances on challenge with 2009 pandemic h1n1 virus. | compared to seasonal influenza viruses, the 2009 pandemic h1n1 (ph1n1) virus caused greater morbidity and mortality in children and young adults. people over 60 years of age showed a higher prevalence of cross-reactive ph1n1 antibodies, suggesting that they were previously exposed to an influenza virus or vaccine that was antigenically related to the ph1n1 virus. to define the basis for this cross-reactivity, ferrets were infected with h1n1 viruses of variable antigenic distance that circulated ... | 2012 | 22674976 |
| the 2009 pandemic influenza virus: where did it come from, where is it now, and where is it going? | around 2008 or 2009, an influenza a virus that had been circulating undetected in swine entered human population. unlike most swine influenza infections of humans, this virus established sustained human-to-human transmission, leading to a global pandemic. the virus responsible, 2009 pandemic h1n1 (h1n1pdm), is the result of multiple reassortment events that brought together genomic segments from classical h1n1 swine influenza virus, human seasonal h3n2 influenza virus, north american avian influ ... | 2013 | 22638836 |
| in vivo evaluation of pathogenicity and transmissibility of influenza a(h1n1)pdm09 hemagglutinin receptor binding domain 222 intrahost variants isolated from a single immunocompromised patient. | the influenza a(h1n1)pdm09 virus has circulated worldwide and continued to cause complicated infections and deaths. reports have identified an increased prevalence of the hemagglutinin receptor binding domain d222g mutation in viruses isolated from individuals who have suffered such severe infections, but this association is still unclear. virus isolated from a nasopharyngeal wash of a severely ill immunocompromised patient at the time of diagnosis contained the d222, but isolates collected late ... | 2012 | 22575875 |
| pb1-f2 modulates early host responses but does not affect the pathogenesis of h1n1 seasonal influenza virus. | in the context of infections with highly pathogenic influenza a viruses, the pb1-f2 protein contributes to virulence and enhances lung inflammation. in contrast, its role in the pathogenesis of seasonal influenza viral strains is less clear, especially in the h1n1 subtype, where strains can have a full-length 87- to 90-amino-acid protein, a truncated 57-amino-acid version, or lack the protein altogether. toward this, we introduced the full-length 1918 pb1-f2, or prevented pb1-f2 expression, in h ... | 2012 | 22318139 |
| modification of the ferret model for pneumonia from seasonal human influenza a virus infection. | the primary complication of seasonal influenza in humans is viral pneumonia. a conventional animal model--intranasal inoculation of ferrets with 10(6) median tissue culture infectious dose of virus--results in disease that is neither consistent nor comparable with severe viral pneumonia in humans. therefore, the authors modified the experimental procedures by increasing the median tissue culture infectious dose to 10(9) and by inoculating via the intratracheal route, testing these procedures wit ... | 2012 | 22262355 |
| new reassortant and enzootic european swine influenza viruses transmit efficiently through direct contact in the ferret model. | the reverse zoonotic events that introduced the 2009 pandemic influenza virus into pigs have drastically increased the diversity of swine influenza viruses in europe. the pandemic potential of these novel reassortments is still unclear, necessitating enhanced surveillance of european pigs with additional focus on risk assessment of these new viruses. in this study, four european swine influenza viruses were assessed for their zoonotic potential. two of the four viruses were enzootic viruses of s ... | 2015 | 25701826 |
| h7n9 live attenuated influenza vaccine is highly immunogenic, prevents virus replication, and protects against severe bronchopneumonia in ferrets. | avian influenza viruses continue to cross the species barrier, and if such viruses become transmissible among humans, it would pose a great threat to public health. since its emergence in china in 2013, h7n9 has caused considerable morbidity and mortality. in the absence of a universal influenza vaccine, preparedness includes development of subtype-specific vaccines. in this study, we developed and evaluated in ferrets an intranasal live attenuated influenza vaccine (laiv) against h7n9 based on ... | 2016 | 26796670 |
| generation and characterization of live attenuated influenza a(h7n9) candidate vaccine virus based on russian donor of attenuation. | avian influenza a (h7n9) virus has emerged recently and continues to cause severe disease with a high mortality rate in humans prompting the development of candidate vaccine viruses. live attenuated influenza vaccines (laiv) are 6:2 reassortant viruses containing the ha and na gene segments from wild type influenza viruses to induce protective immune responses and the six internal genes from master donor viruses (mdv) to provide temperature sensitive, cold-adapted and attenuated phenotypes. | 2015 | 26405798 |
| a single dose of an avian h3n8 influenza virus vaccine is highly immunogenic and efficacious against a recently emerged seal influenza virus in mice and ferrets. | h3n8 influenza viruses are a commonly found subtype in wild birds, usually causing mild or no disease in infected birds. however, they have crossed the species barrier and have been associated with outbreaks in dogs, pigs, donkeys, and seals and therefore pose a threat to humans. a live attenuated, cold-adapted (ca) h3n8 vaccine virus was generated by reverse genetics using the wild-type (wt) hemagglutinin (ha) and neuraminidase (na) genes from the a/blue-winged teal/texas/sg-00079/2007 (h3n8) ( ... | 2015 | 25903333 |
| live attenuated influenza h7n3 vaccine is safe, immunogenic and confers protection in animal models. | in 2003 the outbreak of highly pathogenic h7 avian influenza occurred in the netherlands. the avian h7 virus causing the outbreak was also detected in humans; one person died of pneumonia and acute respiratory distress syndrome. our paper describes preclinical studies of a h7n3 live attenuated influenza a vaccine (laiv) candidate in various animal models. | 2014 | 25685247 |
| replication of live attenuated cold-adapted h2n2 influenza virus vaccine candidates in non human primates. | the development of an h2n2 vaccine is a priority in pandemic preparedness planning. we previously showed that a single dose of a cold-adapted (ca) h2n2 live attenuated influenza vaccine (laiv) based on the influenza a/ann arbor/6/60 (aa ca) virus was immunogenic and efficacious in mice and ferrets. however, in a phase i clinical trial, viral replication was restricted and immunogenicity was poor. in this study, we compared the replication of four h2n2 laiv candidate viruses, aa ca, a/tecumseh/3/ ... | 2015 | 25444799 |
| a live attenuated equine h3n8 influenza vaccine is highly immunogenic and efficacious in mice and ferrets. | equine influenza viruses (eiv) are responsible for rapidly spreading outbreaks of respiratory disease in horses. although natural infections of humans with eiv have not been reported, experimental inoculation of humans with these viruses can lead to a productive infection and elicit a neutralizing antibody response. moreover, eiv have crossed the species barrier to infect dogs, pigs, and camels and therefore may also pose a threat to humans. based on serologic cross-reactivity of h3n8 eiv from d ... | 2015 | 25410860 |
| development and pre-clinical evaluation of two laiv strains against potentially pandemic h2n2 influenza virus. | h2n2 influenza a caused the asian flu pandemic in 1957, circulated for more than 10 years and disappeared from the human population after 1968. given that people born after 1968 are naïve to h2n2, that the virus still circulates in wild birds and that this influenza subtype has a proven pandemic track record, h2n2 is regarded as a potential pandemic threat. to prepare for an h2n2 pandemic, here we developed and tested in mice and ferrets two live attenuated influenza vaccines based on the haemag ... | 2014 | 25058039 |
| risk assessment of h2n2 influenza viruses from the avian reservoir. | h2n2 influenza a viruses were the cause of the 1957-1958 pandemic. historical evidence demonstrates they arose from avian virus ancestors, and while the h2n2 subtype has disappeared from humans, it persists in wild and domestic birds. reemergence of h2n2 in humans is a significant threat due to the absence of humoral immunity in individuals under the age of 50. thus, examination of these viruses, particularly those from the avian reservoir, must be addressed through surveillance, characterizatio ... | 2014 | 24227848 |
| recently emerged swine influenza a virus (h2n3) causes severe pneumonia in cynomolgus macaques. | the triple reassortant h2n3 virus isolated from diseased pigs in the united states in 2006 is pathogenic for certain mammals without prior adaptation and transmits among swine and ferrets. adaptation, in the h2 hemagglutinin derived from an avian virus, includes the ability to bind to the mammalian receptor, a significant prerequisite for infection of mammals, in particular humans, which poses a big concern for public health. here we investigated the pathogenic potential of swine h2n3 in cynomol ... | 2012 | 22808082 |
| amino acids in hemagglutinin antigenic site b determine antigenic and receptor binding differences between a(h3n2)v and ancestral seasonal h3n2 influenza viruses. | influenza a h3n2 variant [a(h3n2)v] viruses, which have caused human infections in the united states in recent years, originated from human seasonal h3n2 viruses that were introduced into north american swine in the mid-1990s, but they are antigenically distinct from both the ancestral and current circulating h3n2 strains. a reference a(h3n2)v virus, a/minnesota/11/2010 (mn/10), and a seasonal h3n2 strain, a/beijing/32/1992 (bj/92), were chosen to determine the molecular basis for the antigenic ... | 2017 | 27807224 |
| peripheral leukocyte migration in ferrets in response to infection with seasonal influenza virus. | in order to better understand inflammation associated with influenza virus infection, we measured cell trafficking, via flow cytometry, to various tissues in the ferret model following infection with an a(h3n2) human seasonal influenza virus (a/perth/16/2009). changes in immune cells were observed in the blood, bronchoalveolar lavage fluid, and spleen, as well as lymph nodes associated with the site of infection or distant from the respiratory system. nevertheless clinical symptoms were mild, wi ... | 2016 | 27315117 |
| effects of egg-adaptation on receptor-binding and antigenic properties of recent influenza a (h3n2) vaccine viruses. | influenza a virus (subtype h3n2) causes seasonal human influenza and is included as a component of influenza vaccines. the majority of vaccine viruses are isolated and propagated in eggs, which commonly results in amino acid substitutions in the haemagglutinin (ha) glycoprotein. these substitutions can affect virus receptor-binding and alter virus antigenicity, thereby, obfuscating the choice of egg-propagated viruses for development into candidate vaccine viruses. to evaluate the effects of egg ... | 2016 | 26974849 |
| impact of a large deletion in the neuraminidase protein identified in a laninamivir-selected influenza a/brisbane/10/2007 (h3n2) variant on viral fitness in vitro and in ferrets. | viral fitness of a laninamivir-selected influenza a/brisbane/10/2007-like (h3n2) isolate (lrvp9) containing a 237-amino acid neuraminidase deletion and a p194l hemagglutinin mutation was evaluated in vitro and in ferrets. lrvp9 and the wild-type (wt) virus showed comparable replication kinetics in mdck-st6gali cells. cultured virus was recovered between days 2 and 5 post-infection in nasal washes (nw) from the 4 wt-infected ferrets whereas no virus was recovered from the lrvp9-infected animals. ... | 2016 | 26526406 |
| oseltamivir population pharmacokinetics in the ferret: model application for pharmacokinetic/pharmacodynamic study design. | the ferret is a suitable small animal model for preclinical evaluation of efficacy of antiviral drugs against various influenza strains, including highly pathogenic h5n1 viruses. rigorous pharmacokinetics/pharmacodynamics (pk/pd) assessment of ferret data has not been conducted, perhaps due to insufficient information on oseltamivir pk. here, based on pk data from several studies on both uninfected and influenza-infected groups (i.e., with influenza a viruses of h5n1 and h3n2 subtypes and an inf ... | 2015 | 26460484 |
| antigenic maps of influenza a(h3n2) produced with human antisera obtained after primary infection. | antigenic characterization of influenza viruses is typically based on hemagglutination inhibition (hi) assay data for viral isolates tested against strain-specific postinfection ferret antisera. here, similar virus characterizations were performed using serological data from humans with primary influenza a(h3n2) infection. | 2016 | 26142433 |
| [virological characteristics of influenza a (h3n2) virus in mainland china during 2013-2014]. | to analyze the antigenic and genetic characteristics of the influenza a (h3n2) virus in mainland china during the surveillance year of 2013-2014, the antigenic characteristics of h3n2 virus were analyzed using reference ferret anti-sera. the nucleotide sequences of the viruses were determined by sanger dideoxy sequencing, phylogenetic trees were constructed with the neighbor-joining method, and the genetic characteristics of the viruses were determined in comparison to current vaccine strains. t ... | 2015 | 25997327 |
| environmental conditions affect exhalation of h3n2 seasonal and variant influenza viruses and respiratory droplet transmission in ferrets. | the seasonality of influenza virus infections in temperate climates and the role of environmental conditions like temperature and humidity in the transmission of influenza virus through the air are not well understood. using ferrets housed at four different environmental conditions, we evaluated the respiratory droplet transmission of two influenza viruses (a seasonal h3n2 virus and an h3n2 variant virus, the etiologic virus of a swine to human summertime infection) and concurrently characterize ... | 2015 | 25969995 |
| the repeated introduction of the h3n2 virus from human to swine during 1979-1993 in china. | limited data are available regarding the swine influenza viruses (sivs) that circulated in mainland china prior to the 1990s. eleven h3n2 virus strains were isolated from swine populations from 1979 to 1992. to determine the origin and tendency of these sivs, the phylogenetic and antigenic properties of these viruses were analyzed based on the whole genome sequenced and the hi titrations with post-infection ferret antisera against influenza a (h3n2) virus isolates of swine and human origin. the ... | 2015 | 25858119 |
| optimization of an enzyme-linked lectin assay suitable for rapid antigenic characterization of the neuraminidase of human influenza a(h3n2) viruses. | antibodies to neuraminidase (na), the second most abundant surface protein of the influenza virus, contribute to protection against influenza virus infection. although traditional and miniaturized thiobarbituric acid (tba) neuraminidase inhibition (ni) assays have been successfully used to characterize the antigenic properties of na, these methods are cumbersome and not easily amendable to rapid screening. an additional difficulty of the ni assay is the interference by hemagglutinin (ha)-specifi ... | 2015 | 25712563 |
| comparative analysis of virulence of a novel, avian-origin h3n2 canine influenza virus in various host species. | a novel avian-origin h3n2 canine influenza a virus (civ) that showed high sequence similarities in hemagglutinin and neuraminidase genes with those of non-pathogenic avian influenza viruses was isolated in our routine surveillance program in south korea. we previously reported that the pathogenicity of this strain could be reproduced in dogs and cats. in the present study, the host tropism of h3n2 civ was examined by experimental inoculation into several host species, including chickens, pigs, m ... | 2015 | 25218482 |
| performance characteristics of qualified cell lines for isolation and propagation of influenza viruses for vaccine manufacturing. | cell culture is now available as a method for the production of influenza vaccines in addition to eggs. in accordance with currently accepted practice, viruses recommended as candidates for vaccine manufacture are isolated and propagated exclusively in hens' eggs prior to distribution to manufacturers. candidate vaccine viruses isolated in cell culture are not available to support vaccine manufacturing in mammalian cell bioreactors so egg-derived viruses have to be used. recently influenza a (h3 ... | 2014 | 24975811 |
| impact of prior seasonal h3n2 influenza vaccination or infection on protection and transmission of emerging variants of influenza a(h3n2)v virus in ferrets. | influenza h3n2 a viruses continue to circulate in swine and occasionally infect humans, resulting in outbreaks of variant influenza h3n2 [a(h3n2)v] virus. it has been previously demonstrated in ferrets that a(h3n2)v viruses transmit as efficiently as seasonal influenza viruses, raising concern over the pandemic potential of these viruses. however, a(h3n2)v viruses have not acquired the ability to transmit efficiently among humans, which may be due in part to existing cross-reactive immunity to a ... | 2013 | 24089569 |
| mutation from arginine to lysine at the position 189 of hemagglutinin contributes to the antigenic drift in h3n2 swine influenza viruses. | two distinct antigenic clusters were previously identified among the h3n2 swine influenza a viruses (iavs) and were designated h3n2siv-alpha and h3n2siv-beta (feng et al., 2013. journal of virology 87 (13), 7655-7667). a consistent mutation was observed at the position 189 of hemagglutinin (r189k) between h3n2siv-alpha and h3n2siv-beta fair isolates. to evaluate the contribution of r189k mutation to the antigenic drift from h3n2siv-alpha to h3n2siv-beta, four reassortant viruses with 189r or 189 ... | 2013 | 24074585 |
| pathogenesis and transmission of avian influenza a (h7n9) virus in ferrets and mice. | on 29 march 2013, the chinese center for disease control and prevention confirmed the first reported case of human infection with an avian influenza a(h7n9) virus. the recent human infections with h7n9 virus, totalling over 130 cases with 39 fatalities to date, have been characterized by severe pulmonary disease and acute respiratory distress syndrome (ards). this is concerning because h7 viruses have typically been associated with ocular disease in humans, rather than severe respiratory disease ... | 2013 | 23842497 |
| seasonal trivalent inactivated influenza vaccine does not protect against newly emerging variants of influenza a (h3n2v) virus in ferrets. | the recent increase in human cases of influenza a h3n2 variant virus [a(h3n2)v] highlights the need to assess whether seasonal influenza vaccination provides cross-protection against a(h3n2)v virus. our data demonstrate that the 2011-2012 trivalent inactivated influenza vaccine (tiv) protected ferrets against homologous h3n2 virus challenge but provided minimal to no protection against a(h3n2)v virus. the complete absence of specific hemagglutination inhibition antibody response to a(h3n2)v is c ... | 2013 | 23115290 |
| surface glycoproteins of influenza a h3n2 virus modulate virus replication in the respiratory tract of ferrets. | the hemagglutinin (ha) genes of the influenza a h3n2 subtype viruses isolated from 1968 to 2010 have evolved substantially but their neuraminidase (na) genes have been relatively less divergent. the h3n2 viruses isolated since 1995 were found to replicate in the lower respiratory tract of ferrets less efficiently than the earlier isolates. to evaluate whether the ha or/and na or the internal protein gene segments of the h3n2 virus affected viral replication in the respiratory tract of ferrets, r ... | 2012 | 22743127 |
| evaluation of influenza virus a/h3n2 and b vaccines on the basis of cross-reactivity of postvaccination human serum antibodies against influenza viruses a/h3n2 and b isolated in mdck cells and embryonated hen eggs. | the vaccine strains against influenza virus a/h3n2 for the 2010-2011 season and influenza virus b for the 2009-2010 and 2010-2011 seasons in japan are a high-growth reassortant a/victoria/210/2009 (x-187) strain and an egg-adapted b/brisbane/60/2008 (victoria lineage) strain, respectively. hemagglutination inhibition (hi) tests with postinfection ferret antisera indicated that the antisera raised against the x-187 and egg-adapted b/brisbane/60/2008 vaccine production strains poorly inhibited rec ... | 2012 | 22492743 |
| pathogenesis and transmission of swine origin a(h3n2)v influenza viruses in ferrets. | recent isolation of a novel swine-origin influenza a h3n2 variant virus [a(h3n2)v] from humans in the united states has raised concern over the pandemic potential of these viruses. here, we analyzed the virulence, transmissibility, and receptor-binding preference of four a(h3n2)v influenza viruses isolated from humans in 2009, 2010, and 2011. high titers of infectious virus were detected in nasal turbinates and nasal wash samples of a(h3n2)v-inoculated ferrets. all four a(h3n2)v viruses possesse ... | 2012 | 22355116 |
| evolution and divergence of h3n8 equine influenza viruses circulating in the united kingdom from 2013 to 2015. | equine influenza viruses (eiv) are a major cause of acute respiratory disease in horses worldwide and occasionally also affect vaccinated animals. like other influenza a viruses, they undergo antigenic drift, highlighting the importance of both surveillance and virus characterisation in order for vaccine strains to be kept up to date. the aim of the work reported here was to monitor the genetic and antigenic changes occurring in eiv circulating in the uk from 2013 to 2015 and to identify any evi ... | 2017 | 28208721 |
| respiratory transmission of an avian h3n8 influenza virus isolated from a harbour seal. | the ongoing human h7n9 influenza infections highlight the threat of emerging avian influenza viruses. in 2011, an avian h3n8 influenza virus isolated from moribund new england harbour seals was shown to have naturally acquired mutations known to increase the transmissibility of highly pathogenic h5n1 influenza viruses. to elucidate the potential human health threat, here we evaluate a panel of avian h3n8 viruses and find that the harbour seal virus displays increased affinity for mammalian recep ... | 2014 | 25183346 |
| development of a surveillance scheme for equine influenza in the uk and characterisation of viruses isolated in europe, dubai and the usa from 2010-2012. | equine influenza viruses are a major cause of respiratory disease in horses worldwide and undergo antigenic drift. several outbreaks of equine influenza occurred worldwide during 2010-2012, including in vaccinated animals, highlighting the importance of surveillance and virus characterisation. virus isolates were characterised from more than 20 outbreaks over a 3-year period, including strains from the uk, dubai, germany and the usa. the haemagglutinin-1 (ha1) sequence of all isolates was determ ... | 2014 | 24480583 |
| the immune correlates of protection for an avian influenza h5n1 vaccine in the ferret model using oil-in-water adjuvants. | because of the pathogenicity and low incidence of avian influenza virus infections in humans, the immune correlates of protection for avian influenza vaccines cannot be determined from clinical studies. here, we used the ferret model to address this for an avian influenza h5n1 vaccine. using oil-in-water adjuvants, we generated groups of ferrets with undetectable (geometric mean titer [gmt] < 10), low (gmt = 28.3), or high (gmt > 761.1) hemagglutination-inhibition (hai) titers to the a/viet nam/ ... | 2017 | 28303960 |
| shifting clade distribution, reassortment, and emergence of new subtypes of highly pathogenic avian influenza a(h5) viruses collected from vietnamese poultry from 2012 to 2015. | whole-genome sequences of representative highly pathogenic avian influenza a(h5) viruses from vietnam were generated, comprising samples from poultry outbreaks and active market surveillance collected from january 2012 to august 2015. six hemagglutinin gene clades were characterized. clade 1.1.2 was predominant in southern mekong provinces throughout 2012 and 2013 but gradually disappeared and was not detected after april 2014. clade 2.3.2.1c viruses spread rapidly during 2012 and were detected ... | 2017 | 28003481 |
| highly pathogenic reassortant avian influenza a(h5n1) virus clade 2.3.2.1a in poultry, bhutan. | highly pathogenic avian influenza a(h5n1), clade 2.3.2.1a, with an h9-like polymerase basic protein 1 gene, isolated in bhutan in 2012, replicated faster in vitro than its h5n1 parental genotype and was transmitted more efficiently in a chicken model. these properties likely help limit/eradicate outbreaks, combined with strict control measures. | 2016 | 27584733 |
| vaccination is more effective than prophylactic oseltamivir in preventing cns invasion by h5n1 virus via the olfactory nerve. | influenza a viruses can replicate in the olfactory mucosa and subsequently use the olfactory nerve to enter the central nervous system (cns). it is currently unknown whether intervention strategies are able to reduce or prevent influenza virus replication within the olfactory mucosa and subsequent spread to the cns. therefore, we tested the efficacy of homologous vaccination and prophylactic oseltamivir to prevent h5n1 virus cns invasion via the olfactory nerve in our ferret model. | 2016 | 27448390 |
| a cationic liposome-dna complexes adjuvant (jvrs-100) enhances the immunogenicity and cross-protective efficacy of pre-pandemic influenza a (h5n1) vaccine in ferrets. | influenza a (h5n1) viruses continue to pose a public health threat. as inactivated h5n1 vaccines are poorly immunogenic, adjuvants are needed to improve the immunogenicity of h5n1 vaccine in humans. here, we investigated the immunogenicity and cross-protective efficacy in ferrets of a clade 2.2-derived vaccine with addition of jvrs-100, an adjuvant consisting of cationic liposome-dna complexes (cldc). after the first vaccination, significantly higher levels of hemagglutination-inhibition (hai) a ... | 2016 | 26967975 |
| identification of stabilizing mutations in an h5 hemagglutinin influenza virus protein. | highly pathogenic avian influenza viruses of the h5n1 subtype continue to circulate in poultry in asia, africa, and the middle east. recently, outbreaks of novel reassortant h5 viruses have also occurred in north america. although the number of human infections with highly pathogenic h5n1 influenza viruses continues to rise, these viruses remain unable to efficiently transmit between humans. however, we and others have identified h5 viruses capable of respiratory droplet transmission in ferrets. ... | 2015 | 26719265 |
| matrix-m adjuvated seasonal virosomal influenza vaccine induces partial protection in mice and ferrets against avian h5 and h7 challenge. | there is a constant threat of zoonotic influenza viruses causing a pandemic outbreak in humans. it is virtually impossible to predict which virus strain will cause the next pandemic and it takes a considerable amount of time before a safe and effective vaccine will be available once a pandemic occurs. in addition, development of pandemic vaccines is hampered by the generally poor immunogenicity of avian influenza viruses in humans. an effective pre-pandemic vaccine is therefore required as a fir ... | 2015 | 26402787 |
| pathobiological features of a novel, highly pathogenic avian influenza a(h5n8) virus. | the endemicity of highly pathogenic avian influenza (hpai) a(h5n1) viruses in asia has led to the generation of reassortant h5 strains with novel gene constellations. a newly emerged hpai a(h5n8) virus caused poultry outbreaks in the republic of korea in 2014. because newly emerging high-pathogenicity h5 viruses continue to pose public health risks, it is imperative that their pathobiological properties be examined. here, we characterized a/mallard duck/korea/w452/2014 (mdk/w452(h5n8)), a repres ... | 2014 | 26038499 |
| intranasal vaccination with a plant-derived h5 ha vaccine protects mice and ferrets against highly pathogenic avian influenza virus challenge. | 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 ... | 2015 | 25714901 |
| pb2 segment promotes high-pathogenicity of h5n1 avian influenza viruses in mice. | h5n1 influenza viruses with high lethality are a continuing threat to humans and poultry. recently, h5n1 high-pathogenicity avian influenza virus (hpaiv) has been shown to transmit through aerosols between ferrets in lab experiments by acquiring some mutation. this is another deeply aggravated threat of h5n1 hpaiv to humans. to further explore the molecular determinant of h5n1 hpaiv virulence in a mammalian model, we compared the virulence of a/duck/guangdong/212/2004 (dk212) and a/quail/guangdo ... | 2015 | 25713566 |
| an anti-h5n1 influenza virus fcdart antibody is a highly efficacious therapeutic agent and prophylactic against h5n1 influenza virus infection. | highly pathogenic h5n1 avian influenza viruses are associated with severe disease in humans and continue to be a pandemic threat. while vaccines are available, other approaches are required for patients that typically respond poorly to vaccination, such as the elderly and the immunocompromised. to produce a therapeutic agent that is highly efficacious at low doses and is broadly specific against antigenically drifted h5n1 influenza viruses, we developed two neutralizing monoclonal antibodies and ... | 2015 | 25673719 |
| intranasal immunization of recombinant lactococcus lactis induces protection against h5n1 virus in ferrets. | the increasing outbreaks of highly pathogenic avian influenza a (hpai) h5n1 viruses in birds and human bring out an urgent need to develop a safe and effective vaccine to control and prevent h5n1 infection. lactococcus lactis (l. lactis) based vaccine platform is a promising approach for mucosal h5n1 vaccine development. intranasal immunization is the potential to induce mucosal immune response which is associated with protective immunity. to develop a safe and effective mucosal vaccine against ... | 2015 | 25445345 |
| identification of molecular markers associated with alteration of receptor-binding specificity in a novel genotype of highly pathogenic avian influenza a(h5n1) viruses detected in cambodia in 2013. | human infections with influenza a(h5n1) virus in cambodia increased sharply during 2013. molecular characterization of viruses detected in clinical specimens from human cases revealed the presence of mutations associated with the alteration of receptor-binding specificity (k189r, q222l) and respiratory droplet transmission in ferrets (n220k with q222l). discovery of quasispecies at position 222 (q/l), in addition to the absence of the mutations in poultry/environmental samples, suggested that th ... | 2014 | 25210193 |
| mammalian models for the study of h7 virus pathogenesis and transmission. | mammalian models, most notably the mouse and ferret, have been instrumental in the assessment of avian influenza virus pathogenicity and transmissibility, and have been used widely to characterize the molecular determinants that confer h5n1 virulence in mammals. however, while h7 influenza viruses have typically been associated with conjunctivitis and/or mild respiratory disease in humans, severe disease and death is also possible, as underscored by the recent emergence of h7n9 viruses in china. ... | 2014 | 24996862 |
| high doses of highly pathogenic avian influenza virus in chicken meat are required to infect ferrets. | high pathogenicity avian influenza viruses (hpaiv) have caused fatal infections in mammals through consumption of infected bird carcasses or meat, but scarce information exists on the dose of virus required and the diversity of hpaiv subtypes involved. ferrets were exposed to different hpaiv (h5 and h7 subtypes) through consumption of infected chicken meat. the dose of virus needed to infect ferrets through consumption was much higher than via respiratory exposure and varied with the virus strai ... | 2014 | 24894438 |
| african green monkeys recapitulate the clinical experience with replication of live attenuated pandemic influenza virus vaccine candidates. | live attenuated cold-adapted (ca) h5n1, h7n3, h6n1, and h9n2 influenza vaccine viruses replicated in the respiratory tract of mice and ferrets, and 2 doses of vaccines were immunogenic and protected these animals from challenge infection with homologous and heterologous wild-type (wt) viruses of the corresponding subtypes. however, when these vaccine candidates were evaluated in phase i clinical trials, there were inconsistencies between the observations in animal models and in humans. the vacci ... | 2014 | 24807726 |
| identification, characterization, and natural selection of mutations driving airborne transmission of a/h5n1 virus. | recently, a/h5n1 influenza viruses were shown to acquire airborne transmissibility between ferrets upon targeted mutagenesis and virus passage. the critical genetic changes in airborne a/indonesia/5/05 were not yet identified. here, five substitutions proved to be sufficient to determine this airborne transmission phenotype. substitutions in pb1 and pb2 collectively caused enhanced transcription and virus replication. one substitution increased ha thermostability and lowered the ph of membrane f ... | 2014 | 24725402 |
| highly pathogenic avian influenza a virus (h5n1) can be transmitted in ferrets by transfusion. | highly pathogenic avian influenza a virus has been shown to infect organs other than the lung, and this is likely to be mediated by systemic spread resulting from viremia which has been detected in blood in severe cases of infection with avian h5n1 viruses. the infectivity of virus in blood and the potential for virus transmission by transfusion has not been investigated. | 2014 | 24712669 |
| a novel neutralizing antibody against diverse clades of h5n1 influenza virus and its mutants capable of airborne transmission. | highly pathogenic avian influenza a virus h5n1 continues to spread among poultry and has frequently broken the species barrier to humans. recent studies have shown that a laboratory-mutated or reassortant h5n1 virus bearing hemagglutinin (ha) with as few as four or five mutations was capable of transmitting more efficiently via respiratory droplets between ferrets, posing a serious threat to public health and underscoring the priority of effective vaccines and therapeutics. in this study, we ide ... | 2014 | 24681124 |
| a model for early onset of protection against lethal challenge with highly pathogenic h5n1 influenza virus. | highly pathogenic avian influenza viruses of subtype h5n1 sporadically cause severe disease in humans and involve the risk of inducing a pandemic by gaining the ability for human-to-human transmission. in naïve poultry, primarily gallinaceous birds, the virus induces fatal disease and the used inactivated vaccines occasionally are unable to provide efficient and early onset of protection. therefore, optimized vaccines must be developed and evaluated in model systems. in our study, we tested a no ... | 2014 | 24674664 |
| assessing the fitness of distinct clades of influenza a (h9n2) viruses. | influenza a (h9n2) viruses are a genetically diverse population that infects wild and domestic avian species and mammals and contributed the internal gene segments to the a/h5n1 and a/h7n9 viruses associated with lethal human infections. here we comprehensively assess the potential risk to mammals of a diverse panel of a/h9n2 viruses, representing the major h9n2 clades, using a combination of in vitro assays (e.g., antiviral susceptibility and virus growth in primary differentiated human airway ... | 2013 | 26038443 |
| selection on haemagglutinin imposes a bottleneck during mammalian transmission of reassortant h5n1 influenza viruses. | the emergence of human-transmissible h5n1 avian influenza viruses poses a major pandemic threat. h5n1 viruses are thought to be highly genetically diverse both among and within hosts; however, the effects of this diversity on viral replication and transmission are poorly understood. here we use deep sequencing to investigate the impact of within-host viral variation on adaptation and transmission of h5n1 viruses in ferrets. we show that, although within-host genetic diversity in haemagglutinin ( ... | 2013 | 24149915 |
| microrna-based strategy to mitigate the risk of gain-of-function influenza studies. | recent gain-of-function studies in influenza a virus h5n1 strains revealed that as few as three-amino-acid changes in the hemagglutinin protein confer the capacity for viral transmission between ferrets. as transmission between ferrets is considered a surrogate indicator of transmissibility between humans, these studies raised concerns about the risks of gain-of-function influenza a virus research. here we present an approach to strengthen the biosafety of gain-of-function influenza experiments. ... | 2013 | 23934176 |
| limited airborne transmission of h7n9 influenza a virus between ferrets. | wild waterfowl form the main reservoir of influenza a viruses, from which transmission occurs directly or indirectly to various secondary hosts, including humans. direct avian-to-human transmission has been observed for viruses of subtypes a(h5n1), a(h7n2), a(h7n3), a(h7n7), a(h9n2) and a(h10n7) upon human exposure to poultry, but a lack of sustained human-to-human transmission has prevented these viruses from causing new pandemics. recently, avian a(h7n9) viruses were transmitted to humans, cau ... | 2013 | 23925116 |
| structure and receptor-binding properties of an airborne transmissible avian influenza a virus hemagglutinin h5 (vn1203mut). | avian influenza a virus continues to pose a global threat with occasional h5n1 human infections, which is emphasized by a recent severe human infection caused by avian-origin h7n9 in china. luckily these viruses do not transmit efficiently in human populations. with a few amino acid substitutions of the hemagglutinin h5 protein in the laboratory, two h5 mutants have been shown to obtain an air-borne transmission in a mammalian ferret model. here in this study one of the mutant h5 proteins develo ... | 2013 | 23794001 |
| receptor binding by a ferret-transmissible h5 avian influenza virus. | cell-surface-receptor binding by influenza viruses is a key determinant of their transmissibility, both from avian and animal species to humans as well as from human to human. highly pathogenic avian h5n1 viruses that are a threat to public health have been observed to acquire affinity for human receptors, and transmissible-mutant-selection experiments have identified a virus that is transmissible in ferrets, the generally accepted experimental model for influenza in humans. here, our quantitati ... | 2013 | 23615615 |
| mutations in haemagglutinin that affect receptor binding and ph stability increase replication of a pr8 influenza virus with h5 ha in the upper respiratory tract of ferrets and may contribute to transmissibility. | the h5n1 influenza a viruses have circulated widely in the avian population for 10 years with only sporadic infection of humans observed and no sustained human to human transmission. vaccination against potential pandemic strains is one strategy in planning for future influenza pandemics; however, the success of live attenuated vaccines for h5n1 has been limited, due to poor replication in the human upper respiratory tract (urt). mutations that increase the ability of h5n1 viruses to replicate i ... | 2013 | 23486663 |
| h5n1 pathogenesis studies in mammalian models. | h5n1 influenza viruses are capable of causing severe disease and death in humans, and represent a potential pandemic subtype should they acquire a transmissible phenotype. due to the expanding host and geographic range of this virus subtype, there is an urgent need to better understand the contribution of both virus and host responses following h5n1 virus infection to prevent and control human disease. the use of mammalian models, notably the mouse and ferret, has enabled the detailed study of b ... | 2013 | 23458998 |
| influenza viruses with rearranged genomes as live-attenuated vaccines. | h5n1 and h9n2 avian influenza virus subtypes top the world health organization's list for the greatest pandemic potential. inactivated h5n1 vaccines induce limited immune responses and, in the case of live-attenuated influenza virus vaccines (laiv), there are safety concerns regarding the possibility of reassortment between the h5 gene segment and circulating influenza viruses. in order to overcome these drawbacks, we rearranged the genome of an avian h9n2 influenza virus and expressed the entir ... | 2013 | 23449800 |
| quantitative description of glycan-receptor binding of influenza a virus h7 hemagglutinin. | in the context of recently emerged novel influenza strains through reassortment, avian influenza subtypes such as h5n1, h7n7, h7n2, h7n3 and h9n2 pose a constant threat in terms of their adaptation to the human host. among these subtypes, it was recently demonstrated that mutations in h5 and h9 hemagglutinin (ha) in the context of lab-generated reassorted viruses conferred aerosol transmissibility in ferrets (a property shared by human adapted viruses). we previously demonstrated that the quanti ... | 2013 | 23437033 |
| early indicators of disease in ferrets infected with a high dose of avian influenza h5n1. | avian influenza viruses are widespread in birds, contagious in humans, and are categorized as low pathogenicity avian influenza or highly pathogenic avian influenza. ferrets are susceptible to infection with avian and human influenza a and b viruses and have been widely used as a model to study pathogenicity and vaccine efficacy. in this report, the natural history of the h5n1 influenza virus a/vietnam/1203/04 influenza infection in ferrets was examined to determine clinical and laboratory param ... | 2012 | 23240077 |
| identification and structural characterization of a broadly neutralizing antibody targeting a novel conserved epitope on the influenza virus h5n1 hemagglutinin. | the unabated circulation of the highly pathogenic avian influenza a virus/h5n1 continues to be a serious threat to public health worldwide. because of the high frequency of naturally occurring mutations, the emergence of h5n1 variants with high virulence has raised great concerns about the potential transmissibility of the virus in humans. recent studies have shown that laboratory-mutated or reassortant h5n1 viruses could be efficiently transmitted among mammals, particularly ferrets, the best a ... | 2013 | 23221567 |
| an adenovirus-based vaccine with a double-stranded rna adjuvant protects mice and ferrets against h5n1 avian influenza in oral delivery models. | an oral gene-based avian influenza vaccine would allow rapid development and simplified distribution, but efficacy has previously been difficult to achieve by the oral route. this study assessed protection against avian influenza virus challenge using a chimeric adenovirus vector expressing hemagglutinin and a double-stranded rna adjuvant. immunized ferrets and mice were protected upon lethal challenge. further, ferrets immunized by the peroral route induced cross-clade neutralizing antibodies, ... | 2013 | 23155123 |
| spread of influenza virus a (h5n1) clade 2.3.2.1 to bulgaria in common buzzards. | on march 15, 2010, a highly pathogenic avian influenza virus was isolated from the carcass of a common buzzard (buteo buteo) in bulgaria. phylogenetic analyses of the virus showed a close genetic relationship with influenza virus a (h5n1) clade 2.3.2.1 viruses isolated from wild birds in the tyva republic and mongolia during 2009-2010. designated a/common buzzard/bulgaria/38wb/2010, this strain was highly pathogenic in chickens but had low pathogenicity in mice and ferrets and no molecular marke ... | 2012 | 23017273 |
| avian influenza a h5n1 virus: a continuous threat to humans. | we report the first case of severe pneumonia due to co-infection with the emerging avian influenza a (h5n1) virus subclade 2.3.2.1 and mycoplasma pneumoniae. the patient was a returning traveller who had visited a poultry market in south china. we then review the epidemiology, virology, interspecies barrier limiting poultry-to-human transmission, clinical manifestation, laboratory diagnosis, treatment and control measures of h5n1 clades that can be transmitted to humans. the recent controversy r ... | 2012 | 26038430 |
| airborne transmission of influenza a/h5n1 virus between ferrets. | highly pathogenic avian influenza a/h5n1 virus can cause morbidity and mortality in humans but thus far has not acquired the ability to be transmitted by aerosol or respiratory droplet ("airborne transmission") between humans. to address the concern that the virus could acquire this ability under natural conditions, we genetically modified a/h5n1 virus by site-directed mutagenesis and subsequent serial passage in ferrets. the genetically modified a/h5n1 virus acquired mutations during passage in ... | 2012 | 22723413 |
| an optimized real-time pcr to avoid species-/tissue-associated inhibition for h5n1 detection in ferret and monkey tissues. | the real-time pcr diagnostics for avian influenza virus h5n1 in tissue specimens are often suboptimal, since naturally occurring pcr inhibitors present in samples, or unanticipated match of primer to unsequenced species' genome. with the principal aim of optimizing the sybr green real-time pcr method for detecting h5n1 in ferret and monkey (chinese rhesus macaque) tissue specimens, we screened various h5n1 gene-specific primer pairs and tested their ability to sensitively and specifically detect ... | 2012 | 22645461 |
| the future of research and publication on altered h5n1 viruses. | recently, we and others obtained experimental evidence that highly pathogenic avian influenza virus subtype h5 can acquire the ability to transmit via aerosols between ferrets. upon submission of manuscripts describing the results of these studies, the us national science advisory board for biosecurity was consulted and recommended that the main conclusions of the work be published but without the experimental details and mutation data that would enable replication of the experiments. over the p ... | 2012 | 22454474 |
| influenza virus respiratory infection and transmission following ocular inoculation in ferrets. | while influenza viruses are a common respiratory pathogen, sporadic reports of conjunctivitis following human infection demonstrates the ability of this virus to cause disease outside of the respiratory tract. the ocular surface represents both a potential site of virus replication and a portal of entry for establishment of a respiratory infection. however, the properties which govern ocular tropism of influenza viruses, the mechanisms of virus spread from ocular to respiratory tissue, and the p ... | 2012 | 22396651 |
| ferret-transmissible influenza a(h5n1) virus: let us err on the side of caution. | | 2012 | 22396481 |
| mammalian-transmissible h5n1 influenza: facts and perspective. | two recently submitted (but as yet unpublished) studies describe success in creating mutant isolates of h5n1 influenza a virus that can be transmitted via the respiratory route between ferrets; concern has been raised regarding human-to-human transmissibility of these or similar laboratory-generated influenza viruses. furthermore, the potential release of methods used in these studies has engendered a great deal of controversy around publishing potential dual-use data and also has served as a ca ... | 2012 | 22366820 |
| low virulence and lack of airborne transmission of the dutch highly pathogenic avian influenza virus h5n8 in ferrets. | highly pathogenic avian influenza (hpai) h5n8 viruses that emerged in poultry in east asia spread to europe and north america by late 2014. here we show that the european hpai h5n8 viruses differ from the korean and japanese hpai h5n8 viruses by several amino acids and that a dutch hpai h5n8 virus had low virulence and was not transmitted via the airborne route in ferrets. the virus did not cross-react with sera raised against pre-pandemic h5 vaccine strains. this data is useful for public healt ... | 2015 | 26090682 |
| pathogenesis of novel reassortant avian influenza virus a (h5n8) isolates in the ferret. | outbreaks of avian influenza virus h5n8 first occurred in 2014, and spread to poultry farms in korea. although there was no report of human infection by this subtype, it has the potential to threaten human public health. therefore, we evaluated the pathogenesis of h5n8 viruses in ferrets. two representative korean h5n8 strains did not induce mortality and significant respiratory signs after an intranasal challenge in ferrets. however, ferrets intratracheally infected with a/broiler duck/korea/bu ... | 2015 | 25776760 |
| an avian h7n1 gain-of-function experiment of great concern. | inappropriately named gain-of-function influenza research seeks to confer airborne transmission on avian influenza a viruses that otherwise cause only dead-end infections in humans. a recent study has succeeded in doing this with a highly pathogenic ostrich h7n1 virus in a ferret model without loss of virulence. if transposable to humans, this would constitute a novel virus with a case fatality rate ~30 greater than that of spanish flu. a commentary from three distinguished virologists considere ... | 2014 | 25316697 |
| airborne transmission of highly pathogenic h7n1 influenza virus in ferrets. | avian h7 influenza viruses are recognized as potential pandemic viruses, as personnel often become infected during poultry outbreaks. h7 infections in humans typically cause mild conjunctivitis; however, the h7n9 outbreak in the spring of 2013 has resulted in severe respiratory disease. to date, no h7 viruses have acquired the ability for sustained transmission among humans. airborne transmission is considered a requirement for the emergence of pandemic influenza, and advanced knowledge of the m ... | 2014 | 24696487 |
| replication capacity of avian influenza a(h9n2) virus in pet birds and mammals, bangladesh. | avian influenza a(h9n2) is an agricultural and public health threat. we characterized an h9n2 virus from a pet market in bangladesh and demonstrated replication in samples from pet birds, swine tissues, human airway and ocular cells, and ferrets. results implicated pet birds in the potential dissemination and zoonotic transmission of this virus. | 2015 | 26583371 |