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an evaluation of avian influenza diagnostic methods with domestic duck specimens.monitoring of poultry, including domestic ducks, for avian influenza (ai) virus has increased considerably in recent years. however, the current methods validated for the diagnosis and detection of ai virus infection in chickens and turkeys have not been evaluated for performance with samples collected from domestic ducks. in order to ensure that methods for the detection of ai virus or ai virus antibody will perform acceptably well with these specimens, samples collected from domestic ducks exp ...200919630236
phenotypic, genetic, and phylogeographical characterization of avian influenza virus subtype h5n2 isolated from northern pintail (anas acuta) in japan.intercontinental movements of northern pintail (anas acuta) ducks wintering in japan create a high-risk of both incursion and dispersion of avian influenza viruses (aivs) that circulate in the ducks' breeding grounds in siberia and alaska. this predisposition is likely amplified by bi-directional conveyance of aivs between japan and china. in this study, h5n2 viruses were characterized by means of ha cleavage site sequencing and found to be low pathogenic. through entire genome analysis, as well ...200919635509
co-administration of inactivated avian influenza virus with cpg or ril-2 strongly enhances the local immune response after intranasal immunization in chicken.intranasal delivery of vaccines is the most effective means of inducing effective immunity in the upper respiratory tract as well as other mucosal lymphoid tissues. to evaluate the effects of the h5n2 inactivated virus with adjuvant, 120 one-day-old chicks were intranasal immunized with the h5n2 inactivated virus respectively mixed with adjuvant cpg or recombinant il-2 (ril-2). the local immunocompetent cells on the respiratory tract were detected. the results showed that the number of intraepit ...200919647063
spatial analysis of low pathogenic h5n2 avian influenza outbreaks in japan in 2005.we conducted a spatial analysis of low pathogenic h5n2 avian influenza (ai) outbreaks, that affected 41 chicken farms in japan in 2005. a statistically significant (p=0.001) cluster of ai-positive farms was identified in the central part of ibaraki prefecture. inside the ai cluster, the density was high for both chicken farms and chicken population, the proportion of layer finisher type farms was high and the farm size was large. we considered it important to take precautions for ai outbreaks in ...200919652489
comparative pathogenesis of an avian h5n2 and a swine h1n1 influenza virus in pigs.pigs are considered intermediate hosts for the transmission of avian influenza viruses (aivs) to humans but the basic organ pathogenesis of aivs in pigs has been barely studied. we have used 42 four-week-old influenza naive pigs and two different inoculation routes (intranasal and intratracheal) to compare the pathogenesis of a low pathogenic (lp) h5n2 aiv with that of an h1n1 swine influenza virus. the respiratory tract and selected extra-respiratory tissues were examined for virus replication ...200919684857
comparative efficacy of north american and antigenically matched reverse genetics derived h5n9 diva marker vaccines against highly pathogenic asian h5n1 avian influenza viruses in chickens.highly pathogenic (hp) h5n1 avian influenza has become endemic in several countries in asia and africa, and vaccination is being widely used as a control tool. however, there is a need for efficacious vaccines preferably utilizing a diva (differentiate infected from vaccinated animals) marker strategy to allow for improved surveillance of influenza in vaccinated poultry. using a reverse genetics approach, we generated asian rgh5n9 vaccine strain deriving the hemagglutinin gene from a/chicken/ind ...200919686695
highly pathogenic avian influenza virus infection of mallards with homo- and heterosubtypic immunity induced by low pathogenic avian influenza viruses.the potential role of wild birds as carriers of highly pathogenic avian influenza virus (hpaiv) subtype h5n1 is still a matter of debate. consecutive or simultaneous infections with different subtypes of influenza viruses of low pathogenicity (lpaiv) are very common in wild duck populations. to better understand the epidemiology and pathogenesis of hpaiv h5n1 infections in natural ecosystems, we investigated the influence of prior infection of mallards with homo- (h5n2) and heterosubtypic (h4n6) ...200919693268
[comparative study of avian influenza virus propagation in the cell culture and chick embryos].comparative reproduction studies of 7 avian influenza virus strains (h5n1, h5n2, h3n2, h4n6, h7n7) in vero and mdck cell lines have indicated that the mdck cell line is an optimal substrate for all study strains. the maximum viral output depends on trypsin concentrations and infection doses, which can differ for individual viral strains. the use of the optimal parameters of avian influenza virus replication in the mdck cell lines yields virus titers comparable with virus reproduction in the chic ...200919708550
development and application of avian influenza vaccines in china.following the first detection of the highly pathogenic h5n1 avian influenza virus in sick geese in guangdong province in china in 1996, scientists began to develop vaccines in preparation for an avian influenza pandemic. an inactivated h5n2 vaccine was produced from a low pathogenic virus, a/turkey/england/n-28/73, and was used for buffer zone vaccination during h5n1 outbreaks in 2004 in china. we also generated a low pathogenic h5n1 reassortant virus (re-1) that derives its ha and na genes from ...200919768404
thermal inactivation of h5n2 high-pathogenicity avian influenza virus in dried egg white with 7.5% moisture.high-pathogenicity avian influenza viruses (hpaiv) cause severe systemic disease with high mortality in chickens. isolation of hpaiv from the internal contents of chicken eggs has been reported, and this is cause for concern because hpaiv can be spread by movement of poultry products during marketing and trade activity. this study presents thermal inactivation data for the hpaiv strain a/chicken/pa/1370/83 (h5n2) (pa/83) in dried egg white with a moisture content (7.5%) similar to that found in ...200919777906
the polymerase acidic protein gene of influenza a virus contributes to pathogenicity in a mouse model.adaptation of influenza a viruses to a new host species usually involves the mutation of one or more of the eight viral gene segments, and the molecular basis for host range restriction is still poorly understood. to investigate the molecular changes that occur during adaptation of a low-pathogenic avian influenza virus subtype commonly isolated from migratory birds to a mammalian host, we serially passaged the avirulent wild-bird h5n2 strain a/aquatic bird/korea/w81/05 (w81) in the lungs of mic ...200919793828
mucosal immunity induced by adenovirus-based h5n1 hpai vaccine confers protection against a lethal h5n2 avian influenza virus challenge.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) expressi ...200919836045
prior infection with an h1n1 swine influenza virus partially protects pigs against a low pathogenic h5n1 avian influenza virus.most humans lack virus neutralizing (vn) and haemagglutination inhibition (hi) antibodies to h5n1 avian influenza viruses (aivs), but cross-reactive neuraminidase inhibition (ni) antibodies and cell-mediated immune (cmi) responses are common. these immune responses result largely from infections with seasonal human h1n1 influenza viruses, but the protective effect of h1n1 infection-immunity against h5n1 infection has never been examined. to this purpose, we have used the pig model of influenza a ...200919840669
phylogeny and genotyping of recent avian low-pathogenic h5 subtype influenza viruses from french ducks.h5 low-pathogenic avian influenza virus (lpaiv) has the potential to become highly pathogenic and to cause serious problems in animal and public health. aiv surveillance and characterization in both wild and domestic species is therefore necessary. in order to acquire molecular information and to identify possible reassortments in french viruses, we analysed the entire genome of five h5n3, three h5n2 and two h5n1 lpaiv, isolated in france between 2002 and 2008 mostly from captive ducks (free-ran ...201020016038
highly pathogenic h5n1 avian influenza virus induces extracellular ca2+ influx, leading to apoptosis in avian cells.in this study, we show that the highly pathogenic h5n1 avian influenza virus (aiv) (a/crow/kyoto/53/04 and a/chicken/egypt/cl6/07) induced apoptosis in duck embryonic fibroblasts (def). in contrast, apoptosis was reduced among cells infected with low-pathogenic aivs (a/duck/hk/342/78 [h5n2], a/duck/hk/820/80 [h5n3], a/wigeon/osaka/1/01 [h7n7], and a/turkey/wisconsin/1/66 [h9n2]). thus, we investigated the molecular mechanisms of apoptosis induced by h5n1-aiv infection. caspase-dependent and -ind ...201020053741
serologic response and safety to vaccination against avian influenza using inactivated h5n2 vaccine in zoo birds.due to the spread of the h5n1 highly pathogenic strain of avian influenza virus across europe, a preventive vaccination occurred in early 2006 among 135 french zoologic institutions. approximately 25,000 birds were vaccinated with a h5n2 inactivated vaccine. among them, 4,369 birds were monitored by members of association francophone des vétérinaires de parc zoologique regarding safety issues of the vaccination protocol. a total of 1,686 blood samples were collected before the first injection (n ...200920063820
influenza virus in a natural host, the mallard: experimental infection data.wild waterfowl, particularly dabbling ducks such as mallards (anas platyrhynchos), are considered the main reservoir of low-pathogenic avian influenza viruses (lpaivs). they carry viruses that may evolve and become highly pathogenic for poultry or zoonotic. understanding the ecology of lpaivs in these natural hosts is therefore essential. we assessed the clinical response, viral shedding and antibody production of juvenile mallards after intra-esophageal inoculation of two lpaiv subtypes previou ...201020126617
surveillance and characterization of low pathogenic h5 avian influenza viruses isolated from wild migratory birds in korea.migratory waterfowls are the natural reservoir of influenza a viruses. however, interspecies transmission had occasionally caused outbreaks in various hosts including humans. to characterize the genetic origins of h5 avian influenza viruses isolated from migratory birds in south korea, phylogenetic analysis were conducted. a total of 53 h5 viruses were isolated between october 2005 and november 2008. full genetic characterization indicated that most of these viruses belong to the eurasian-like a ...201020227447
characterization of two low pathogenic avian influenza viruses isolated in hungary in 2007.two low pathogenic (lp) avian influenza virus strains, a/mallard/hungary/19616/07 (h3n8) and a/mute swan/hungary/5973/07 (h7n7), isolated as part of the national surveillance program in hungary, were fully sequenced and characterized. the two viruses showed the closest phylogenetic relationship regarding their acidic polymerase genes. the h7n7 hungarian virus and some h5n2 influenza viruses isolated from korean pigs appeared to have their basic polymerase gene 1 from a relatively recent common a ...201020363081
antigenic epitopes in the hemagglutinin of qinghai-type influenza h5n1 virus.the highly pathogenic avian influenza h5n1 viruses have become widespread and evolved into several clades. in our previous studies, the antigenic sites of the h5 hemagglutinin (ha) were characterized by selection and sequencing of escape mutants. in the present studies we analyzed the antigenic epitopes recognized by monoclonal antibodies against avian influenza a/duck/novosibirsk/56/05 (h5n1) virus isolated in western siberia and belonging to subclade 2.2 of the h5n1 viruses. the analysis revea ...201020373998
evaluation of different serological tests for the detection of antibodies against highly pathogenic avian influenza in experimentally infected ostriches (struthio camelus).in the present study we collected 177 serum samples from ostriches (struthio camelus) infected experimentally with a/ostrich/south africa/middleton/2004 (h5n2) highly pathogenic avian influenza virus. we tested these samples using the haemagglutination inhibition (hi) test, the agar gel immunodiffusion test and three enzyme-linked immunosorbent assay kits. we considered the hi test, with homologous antigen and including pre-treatment of sera with 10% chicken red blood cells, as the gold standard ...201020390531
characterization of h5n2 influenza viruses isolated in south korea and their influence on the emergence of a novel h9n2 influenza virus.we characterized low pathogenic avian influenza (lpai) h5n2 and h9n2 viruses isolated in south korea from 2008 to 2009. genetic analysis of the h5n2 viruses isolated from wild birds and domestic ducks demonstrated that they were related to the recently isolated southern chinese lpai h5 viruses and various influenza viruses circulating in eurasia. three h9n2 viruses obtained at live bird markets and duck farms were reassortant viruses generated from the h5n2 viruses of domestic ducks and the h9n2 ...201020392898
prophylactic and therapeutic efficacy of avian antibodies against influenza virus h5n1 and h1n1 in mice.pandemic influenza poses a serious threat to global health and the world economy. while vaccines are currently under development, passive immunization could offer an alternative strategy to prevent and treat influenza virus infection. attempts to develop monoclonal antibodies (mabs) have been made. however, passive immunization based on mabs may require a cocktail of mabs with broader specificity in order to provide full protection since mabs are generally specific for single epitopes. chicken i ...201020405007
[results of clinical trials on reactogenicity, safety, and immunogenicity of influenza allantoic intranasal live vaccine "ultragrivac" (type a/h5n2)].results of phase ii of a clinical trial of the influenza allantoic intranasal live vaccine "ultragrivac" (type a/h5n2) are presented. the vaccine was developed based on strain /17/duck/potsdam/86/92 h5n2 [17/h5] - reassortant of two viruses, /leningrad/134/17/57 (h2n2) and /duck/potsdam/1402-86 (h5n2), obtained from the virology department, st. petersburg institute of experimental medicine.two schemes of immunization (with revaccination on days 10 and 21) were used. evaluation of vaccine immunog ...201020422755
avian influenza in ostriches: epidemiological investigation in the western cape province of south africa.an h5n2 avian influenza virus was isolated from ostriches in the eastern cape province of south africa in july 2004. during a subsequent national survey to determine the possible presence of the disease in other areas of south africa, specific antibodies against h5 avian influenza were detected by the haemagglutination inhibition test in ostrich sera collected in the western cape province. however, the sampling strategy used in the initial survey was developed to accommodate practical constraint ...200620429053
recent outbreaks of avian influenza in japan.recently japan had three outbreaks of avian influenza (al) in 2004, 2005 and 2007. an outbreak of highly pathogenic avian influenza (hpai) was recorded in early 2004, the first for 79 years, with four farms being infected with hpai virus subtype h5n1. in 2005, 41 farms were found to be infected with ai virus subtype h5n2. in early 2007, four farms were infected with hpai virus subtype h5n1 again. in all of these outbreaks, the disease was eradicated without resorting to vaccination, through a ca ...200920462157
characterization and efficacy determination of commercially available central american h5n2 avian influenza vaccines for poultry.a poultry vaccination program was implemented in central america beginning in january 1995 to control both h5n2 low (lpai) and high pathogenicity avian influenza. this study was conducted to identify seed strain composition and the efficacy of 10 commercially available h5 vaccines against challenge with h5n2 lpai viruses isolated from latin america in 2003. the original 1994 vaccine seed virus in commercial inactivated vaccines did not significantly reduce challenge virus shed titers. however, t ...201020470798
avian influenza in north and south america, the caribbean, and australia, 2006-2008.between 2006 and 2008, only one outbreak of highly pathogenic notifiable avian influenza (ai) was reported from the americas, the caribbean, and australia. the outbreak, caused by h7n3, occurred in september 2007 in a multiage broiler breeder facility (approximately 49,000 birds) near regina beach in southern saskatchewan, canada. the disease was confined to a single farm; the farm was depopulated. all other reports of infections in poultry or wild birds involved low pathogenicity ai viruses. a ...201020521630
summary of avian influenza activity in europe, asia, and africa, 2006-2009.events during the period extending from 2006 to 2009 have been overshadowed by the ongoing panzootic with h5n1 (highly pathogenic notifiable avian influenza [hpnai]), which has afflicted 63 countries and three continents (africa, asia, and europe) during the review period. two countries, indonesia and egypt, have formally declared the disease endemic to the world organisation for animal health, while others have used a variety of approaches aimed at containment, control, and eradication. these a ...201020521631
protective dose of a recombinant newcastle disease lasota-avian influenza virus h5 vaccine against h5n2 highly pathogenic avian influenza virus and velogenic viscerotropic newcastle disease virus in broilers with high maternal antibody levels.the protective dose of a live recombinant lasota newcastle disease virus (ndv)-avian influenza h5 vaccine (rndv-ls/ai-h5) was determined in broiler chickens with high levels of maternal antibodies against ndv and avian influenza virus (aiv). at hatch the geometric mean titers (gmt) of the chickens' maternal antibodies were 2(5.1) and 2(10.3) for ndv and aiv, respectively. at the time of vaccination the gmt was 2(3.1) for ndv and 2(7.9) for aiv. the chickens were vaccinated with one drop (0.03 ml ...201020521638
protection and differentiation of infected from vaccinated animals by an inactivated recombinant newcastle disease virus/avian influenza h5 vaccine.specific-pathogen-free chickens immunized at 14 days of age with either an inactivated recombinant newcastle disease virus-lasota/avian influenza h5 (k-rndv-ls/ai-h5) vaccine or a killed newcastle disease/avian influenza whole-virus vaccine (k-nd/ai) were protected from disease when challenged with either a/chicken/queretaro/14588-19/95 (h5n2), a high pathogenicity avian influenza virus (hpaiv) strain isolated in mexico in 1995, or with a mexican velogenic viscerotropic newcastle disease virus ( ...201020521639
passive protection afforded by maternally-derived antibodies in chickens and the antibodies' interference with the protection elicited by avian influenza-inactivated vaccines in progeny.systematic vaccination can be applied when a disease has become enzootic in a country or region. the final goal of the approach is to control or eradicate the disease within the country. this is a long-term vaccination plan that could be applied nationwide to all commercial and backyard poultry. however, after several months of vaccination in enzootic areas, maternally derived antibody (mda) is present in young chicks, providing some protection and/or interference with vaccination. the aim of th ...201020521640
a heterologous neuraminidase subtype strategy for the differentiation of infected and vaccinated animals (diva) for avian influenza virus using an alternative neuraminidase inhibition test.the option of vaccinating poultry against avian influenza (ai) as a control tool is gaining greater acceptance by governments and the poultry industry worldwide. one disadvantage about vaccination with killed whole-virus vaccines is the resulting inability to use common serologic diagnostic tests for surveillance to identify infected flocks. there has been considerable effort to develop a reliable test for the differentiation of infected from vaccinated animals (diva). the heterologous neuramini ...201020521644
phylogenetic analysis of influenza a viruses (h6n8, h1n8, h4n2, h9n2, h10n7) isolated from wild birds, ducks, and ostriches in south africa from 2007 to 2009.influenza a strains emerging from wild birds are a constant threat to south africa's valuable ostrich industry. in 2004 and again in 2006, low pathogenicity avian influenza h5n2 strains introduced from a wild bird reservoir mutated in ostriches to high pathogenicity avian influenza (hpai), with serious economic consequences and export bans imposed by the european union. although no outbreaks of notifiable avian influenza have occurred in south africa since 2006, the h9n2 virus caused a localized ...201020521652
low pathogenicity avian influenza in italy during 2007 and 2008: epidemiology and control.since 1999, the italian poultry production system has experienced several outbreaks of avian influenza (ai), mainly located in northeastern italy. this paper describes the low pathogenicity (lp) ai outbreaks detected during the surveillance activities implemented in 2007-08. from may to october 2007, ten rural and hobby poultry farms were infected by an lpai virus of the h7n3 subtype. in august-october 2007, the h7n3 lpai virus was introduced into the industrial poultry sector with the involveme ...201020521653
surveillance and control of avian influenza in the new york live bird markets.a comprehensive avian influenza control program was established for the new york live bird market (lbm) system. its purpose was to eliminate avian influenza virus (aiv) from the marketing system. the application of science-based surveillance, improved diagnostic performance, voluntary efforts of the lbm owners, and regulatory enforcement have resulted in the elimination of an h7 low pathogenic aiv (lpaiv) that had persisted in the lbm system for 13 yr. although sporadic introductions of h5n2 lpa ...201020521656
surveillance of avian influenza in the caribbean through the caribbean animal health network: surveillance tools and epidemiologic studies.the caribbean region is considered to be at risk for avian influenza (ai) due to a large backyard poultry system, an important commercial poultry production system, the presence of migratory birds, and disparities in the surveillance systems. the caribbean animal health network (caribvet) has developed tools to implement ai surveillance in the region with the goals to have 1) a regionally harmonized surveillance protocol and specific web pages for ai surveillance on www.caribvet.net, and 2) an a ...201020521662
low pathogenicity avian influenza subtypes isolated from wild birds in the united states, 2006-2008.due to concerns that high pathogenicity avian influenza would enter into the united states, an interagency strategic plan was developed to conduct surveillance in wild birds in order to address one of the possible pathways of entry. the usda and state wildlife agencies participated in this effort by collecting samples from 145,055 wild birds from april 2006 through march 2008 in all 50 states. the majority (59%) of all wild bird samples was collected from dabbling ducks, and 91% of h5 detections ...201020521670
presence of serum antibodies to influenza a subtypes h5 and n1 in swans and ibises in french wetlands, irrespective of highly pathogenic h5n1 natural infection.highly pathogenic (hp) avian influenza a viruses (aivs) subtype h5n1 (subclade 2.2) were detected in wild birds during outbreaks in france during winter 2006 and summer 2007 in la dombes wetlands (eastern france) and in moselle wetlands (northeastern france), respectively. blood samples from apparently healthy wild birds were collected in 2006 and 2007 from the end of the outbreak to several weeks after the influenza a outbreak inside and outside the contaminated areas, and in 2008 outside the c ...201020521685
adaptation of a mallard h5n2 low pathogenicity influenza virus in chickens with prior history of infection with infectious bursal disease virus.the influenza a/mallard/pennsylvania/10218/1984 (h5n2) virus is unable to replicate in 3-wk-old immunocompetent specific-pathogen-free chickens when a dose of 5 x 10(6) 50% egg infectious dose/ml is used. in contrast, this mallard virus shows limited replication in 3-wk-old chickens that had been previously infected at 2 days of age with, and recovered from, the immunosuppressive agent infectious bursal disease virus (ibdv; herein referred to as ibdv chickens). this limited replication in ibdv c ...201020521687
studying possible cross-protection of canada geese preexposed to north american low pathogenicity avian influenza virus strains (h3n8, h4n6, and h5n2) against an h5n1 highly pathogenic avian influenza challenge.highly pathogenic avian influenza (hpai) h5n1 virus infections have caused unprecedented morbidity and mortality in different species of domestic and wild birds in asia, europe, and africa. in our previous study, we demonstrated the susceptibility and potential epidemiologic importance of h5n1 hpai virus infections in canada geese. in this study, we investigated the potential of preexposure with north american lineage h3n8, h4n6, and h5n2 low pathogenicity avian influenza (lpai) viruses to cross ...201020521692
the effect of age on avian influenza viral shedding in mallards (anas platyrhynchos).avian influenza virus (aiv) prevalence in wild aquatic bird populations varies with season, geographic location, host species, and age. it is not clear how age at infection affects the extent of viral shedding. to better understand the influence of age at infection on viral shedding of wild bird-origin low pathogenicity avian influenza (lpai) viruses, mallards (anas platyrhynchos) of increasing age (2 wk, 1 mo, 2 mo, 3 mo, and 4 mo) were experimentally inoculated via choanal cleft with a 10(6) m ...201020521698
development and evaluation of an avian influenza, neuraminidase subtype 1, indirect enzyme-linked immunosorbent assay for poultry using the differentiation of infected from vaccinated animals control strategy.an indirect enzyme-linked immunosorbent assay (elisa) was developed using baculovirus, purified, recombinant n1 protein from a/chicken/indonesia/pa7/2003 (h5n1) virus. the n1-elisa showed high selectivity for detection of n1 antibodies, with no cross-reactivity with other neuraminidase subtypes, and broad reactivity with sera to n1 subtype isolates from north american and eurasian lineages. sensitivity of the n1-elisa to detect n1 antibodies in turkey sera, collected 3 wk after h1n1 vaccination, ...201020521703
production of h5-specific monoclonal antibodies and the development of a competitive enzyme-linked immunosorbent assay for detection of h5 antibodies in multiple species.the hemagglutinin gene of an avian influenza virus (aiv) a/duck/nc/674964/07 (h5n2) was cloned and expressed in a baculovirus system (h5-bac). in parallel, a recombinant hemagglutinin of a/vietnam/1203/04 (h5n1) was expressed in mammalian cells, purified, and used for generation of h5-specific monoclonal antibodies (mab). the purified h5-bac was used to develop a competitive enzyme-linked immunosorbent assay (celisa) to detect h5 antibodies in a species-independent approach using one of the esta ...201020521708
interaction between research and diagnosis and surveillance of avian influenza within the caribbean animal health network (caribvet).the caribbean region is considered to be at risk for avian influenza (ai) because of predominance of the backyard poultry system, important commercial poultry production, migratory birds and disparities in the surveillance systems. the caribbean animal health network (caribvet) has developed tools to implement ai surveillance in the region: (i) a regionally harmonized surveillance protocol, (ii) specific web pages for ai surveillance on http://www.caribvet.net, and (iii) a diagnostic network for ...201020537093
evaluation of the protection induced by avian influenza vaccines containing a 1994 mexican h5n2 lpai seed strain against a 2008 egyptian h5n1 hpai virus belonging to clade 2.2.1 by means of serological and in vivo tests.since 2006 egypt has been facing an extensive epidemic of h5n1 highly pathogenic avian influenza (hpai) with a huge number of outbreaks both in rural and intensively reared poultry areas. the use of efficacious vaccines in this country has been, and still remains, essential for the control and possible eradication of hpai. the present study was performed to establish whether the administration of inactivated vaccines containing an h5 virus belonging to a different lineage to the eurasian h5n1 hp ...201020544428
[molecular analysis of an avian influenza virus isolate of h5n2 subtype from parrot].in 2005, an avian influenza virus stain was isolated from parrot in guangdong, which was then genotyped as h5n2 subtype and designated as a/parrot/guangdong/268/2005. according to the current oie definition on the low-pathogenicity of avian influenza virus, the strain was recognized as a low pathogenic avian influenza virus due to the presence of one basic amino acid residue at the ha cleavage site. some molecular characteristics of the virus, such as potential glycosylation sites in ha and na, ...201020572338
epidemiology of avian influenza virus in wild birds in switzerland between 2006 and 2009.after the spread of h5n1 highly pathogenic avian influenza virus (aiv) from asia into russia, the middle east, europe, and africa in 2005-06, the swiss national aiv surveillance program was extended. one of the new focal points was lake constance, where sentinel duck stations and swim-in traps were established within the project constanze in collaboration with germany and austria. more than 2000 samples from 41 species were collected in switzerland between september 2006 and december 2008. appro ...201020608533
isolation and characterization of potentially pathogenic h5n2 influenza virus from a chicken in taiwan in 2008.during the surveillance of avian influenza, an h5n2 influenza a virus was isolated from a cloacal swab sample of an apparently healthy chicken in taiwan in october 2008. it was found that the ha of the virus had a pair of dibasic amino acid residues at the cleavage site, which might be a marker of highly pathogenic avian influenza virus. however, the intravenous pathogenicity index of the isolate was 0.89, indicating that the virus was approaching high pathogenicity in chickens. virus isolation ...201020608534
prior infection of pigs with swine influenza viruses is a barrier to infection with avian influenza viruses.although pigs are susceptible to avian influenza viruses (aiv) of different subtypes, the incidence of aiv infections in the field appears to be low. swine h1n1, h3n2 and h1n2 influenza viruses (siv) are enzootic worldwide and most pigs have antibodies to 1 or more siv subtypes. this study aimed to examine whether infection-immunity to h1n1 or h3n2 siv may (1) protect pigs against subsequent infections with aiv of various haemagglutinin and/or neuraminidase subtypes and/or (2) interfere with the ...201020627621
evaluation of the xpert flu a panel nucleic acid amplification-based point-of-care test for influenza a virus detection and pandemic h1 subtyping.influenza antigenic point-of-care (poc) tests are too insensitive for individual reliable diagnosis of influenza virus infections without additional laboratory confirmation. molecular poc tests could be a valuable alternative.201020674478
surveillance of avian influenza virus in wild bird fecal samples from south korea, 2003-2008.we analyzed the results from nationwide surveillance of avian influenza (ai) from birds in south korea's major wild bird habitats and the demilitarized zone of south korea, 2003-2008. of 28,214 fecal samples analyzed, 225 yielded influenza viruses, for a prevalence of 0.8%. hemagglutinin (ha) subtypes h1-h12 and all nine neuraminidase (na) subtypes were detected. the dominant ha subtypes were h6, h1, and h4, and the most common na subtypes were n2, n1, and n6. among the 38 ha/na subtype combinat ...201020688693
longitudinal 2 years field study of conventional vaccination against highly pathogenic avian influenza h5n1 in layer hens.a licensed, inactivated vaccine based on a low pathogenic avian influenza virus strain (h5n2) was evaluated in layer hens kept under field conditions during a 2-year period. vaccine efficacy was investigated by specific antibodies and by challenge-contact experiments using highly pathogenic avian influenza viruses (hpaiv) h5n1. basic immunization with two applications induced clinical protection. virus excretion by vaccinated hens was significantly reduced compared to non-vaccinated controls; tr ...201020727963
[protective properties of candidate genetically engineered vaccines against avian influenza viruses constructed on the basis of recombinant adenoviral vectors].to design and study the properties of candidate vaccines against avian influenza based on recombinant adenoviral vectors expressing h5 hemagglutinin.201020734718
a highly sensitive immuno-pcr assay for detection of h5n1 avian influenza virus.with an aim at detecting the ultra-low concentration of avian influenza virus (aiv), a highly sensitive hybrid assay based on immunology and polymerase chain reaction was developed. the topyield microtiter plates were coated with ten-fold serial dilutions of h5n1 subtype aiv ranging from 10 eid(50 )ml(-1)~10(-4) eid(50) ml(-1),which was recognized by mouse anti-aiv h5 monoclonal antibody (mab) that was directly linked with reporter dna using a heterobifunctional cross-linker. after extensive was ...201120862550
immunogenicity and protective efficacy of a dna vaccine encoding a chimeric protein of avian influenza hemagglutinin subtype h5 fused to cd154 (cd40l) in pekin ducks.the potential of cd154 (cd40l) as a powerful immunological adjuvant has been shown in various strategies. in this study we examine the immunogenicity and protective efficacy of a cd40-targeting avian influenza hemagglutinin (ha) subunit dna vaccine in ducks. dna constructs encoded the ectodomain of the ha protein of lpai a/mallard/bc/373/2005 (h5n2) with or without fusion to the ectodomain of duck cd154. cd40-targeting significantly accelerated and enhanced humoral responses to the vector-encode ...201020937323
myd88 signaling is indispensable for primary influenza a virus infection but dispensable for secondary infection.recent studies have revealed that innate immunity is involved in the development of adaptive immune responses; however, its role in protection is not clear. in order to elucidate the exact role of toll-like receptor (tlr) or rig-i-like receptor (rlr) signaling on immunogenicity and protective efficacy against influenza a virus infection (a/pr/8/34 [pr8]; h1n1), we adapted several innate signal-deficient mice (e.g., trif(-/-), myd88(-/-), myd88(-/-) trif(-/-), tlr3(-/-) tlr7(-/-), and ips-1(-/-)) ...201020943980
surveillance and identification of influenza a viruses in wild aquatic birds in the crimea, ukraine (2006-2008).the ecology of avian influenza (ai) viruses in wild aquatic birds of asia is poorly understood, especially for the h5n1 high pathogenicity ai (hpai) viruses. from march 2006 through november 2008, 20 ai viruses were isolated in the crimea region of ukraine with an overall frequency of virus recovery of 3.3%. all the viruses were isolated from three species of dabbling ducks: mallard (anas platyrhynchos), wigeon (anas penelope), and garganey (anas querquedula), making the frequency of virus recov ...201020945793
supplemental treatment of air in airborne infection isolation rooms using high-throughput in-room air decontamination units.evidence has recently emerged indicating that in addition to large airborne droplets, fine aerosol particles can be an important mode of influenza transmission that may have been hitherto underestimated. furthermore, recent performance studies evaluating airborne infection isolation (aii) rooms designed to house infectious patients have revealed major discrepancies between what is prescribed and what is actually measured.201021095042
differential effects of ns1 proteins of human pandemic h1n1/2009, avian highly pathogenic h5n1, and low pathogenic h5n2 influenza a viruses on cellular pre-mrna polyadenylation and mrna translation.the nonstructural protein ns1 of influenza a virus blocks the development of host antiviral responses by inhibiting polyadenylation of cellular pre-mrna. ns1 also promotes the synthesis of viral proteins by stimulating mrna translation. here, we show that recombinant ns1 proteins of human pandemic h1n1/2009, avian highly pathogenic h5n1, and low pathogenic h5n2 influenza strains differentially affected these two cellular processes: ns1 of the two avian strains, in contrast to ns1 of h1n1/2009, s ...201021163951
impact of antigenic and genetic drift on the serologic surveillance of h5n2 avian influenza viruses.serologic surveillance of avian influenza (ai) viruses is carried out by the hemagglutination inhibition (hi) test using reference reagents. this method is recommended by animal health organizations as a standard test to detect antigenic differences (subtypes) between circulating influenza virus, vaccine- and/or reference- strains. however, significant discrepancies between reference antisera and field isolates have been observed during serosurveillance of influenza a viruses in pig and poultry ...201021172021
protective efficacy of h5 inactivated vaccines in meat turkey poults after challenge with egyptian variant highly pathogenic avian influenza h5n1 virus.in contrast to chickens, there is a paucity of information on the potency of h5 vaccines to protect turkeys against the highly pathogenic avian influenza (hpai) h5n1 virus infections. in this study, 4 groups, 10 turkey poults each, were vaccinated at seven days old with one of h5n2 or h5n1 commercial vaccines or one of two prepared h5n1 vaccines from a local egyptian variant hpai h5n1 (egyvar/h5n1) strain. at 35 days age, all vaccinated and 10 non vaccinated birds were challenged intranasal with ...201021236607
highly pathogenic avian influenza virus h5n1 from egypt escapes vaccine-induced immunity but confers clinical protection against a heterologous clade 2.2.1 egyptian isolate.the poultry populations of egypt are endemically infected by highly pathogenic avian influenza viruses (hpaiv) of subtype h5n1. vaccination was chosen as an auxiliary tool to control hpaiv in poultry. potency of commercial vaccines regarding emerging variants is under discussion. in the current study efficacy of four different inactivated whole h5 virus vaccines representing different sublineages of hpaiv h5n1 were tested in chickens against challenge viruses currently co-circulating in egypt an ...201121244859
reassortant low-pathogenic avian influenza h5n2 viruses in african wild birds.to investigate the presence and persistence of avian influenza virus in african birds, we monitored avian influenza in wild and domestic birds in two different regions in nigeria. we found low-pathogenic avian influenza (lpai) h5n2 viruses in three spur-winged geese (plectropterus gambensis) in the hadejia-nguru wetlands. phylogenetic analyses revealed that all of the genes, except the non-structural (ns) genes, of the lpai h5n2 viruses were more closely related to genes recently found in wild a ...201121248176
use of a tetanus toxoid marker to allow differentiation of infected from vaccinated poultry without affecting the efficacy of a h5n1 avian influenza virus vaccine.tetanus toxoid (tt) was assessed as a positive marker for avian influenza (ai) virus vaccination in chickens, in a vaccination and challenge study. chickens were vaccinated twice with inactivated ai h5n2 virus vaccine, and then challenged three weeks later with highly pathogenic ai h5n1 virus. vaccinated chickens were compared with other groups that were either sham-vaccinated or vaccinated with virus with the tt marker. all sham-vaccinated chickens died by 36 hours postinfection, whereas all va ...201021257485
association of mx1 asn631 variant alleles with reductions in morbidity, early mortality, viral shedding, and cytokine responses in chickens infected with a highly pathogenic avian influenza virus.myxovirus-resistance (mx) proteins are produced by host cells in response to type i interferons, and some members of the mx gene family in mammals have been shown to limit replication of influenza and other viruses. according to an early report, chicken mx1 variants encoding asn at position 631 have antiviral activity, whereas variants with ser at 631 lack activity in experiments evaluating mx1 complementary dna (cdna) expressed ectopically in a cell line. we evaluated whether the mx1 631 dimorp ...201121286706
further evidence of antigenic drift and protective efficacy afforded by a recombinant hvt-h5 vaccine against challenge with two antigenically divergent egyptian clade 2.2.1 hpai h5n1 strains.in this study, we have compared the protection afforded by a recombinant turkey herpesvirus vaccine expressing the h5 gene from a clade 2.2 h5n1 strain (rhvt-h5) and a mexican-origin h5n2 inactivated vaccine, alone or in combination, against two antigenically divergent h5n1 egyptian strains isolated in 2007 and 2008. our results confirm the existence of a major antigenic drift among the egyptian h5n1 strains such that, although protection against the "classical" 2007 hpai h5n1 egyptian strain co ...201121292007
a low pathogenic h5n2 influenza virus isolated in taiwan acquired high pathogenicity by consecutive passages in chickens.h5n2 viruses were isolated from cloacal swab samples of apparently healthy chickens in taiwan in 2003 and 2008 during surveillance of avian influenza. each of the viruses was eradicated by stamping out. the official diagnosis report indicated that the intravenous pathogenicity indexes (ivpis) of the isolates were 0.00 and 0.89, respectively, indicating that these were low pathogenic strains, although the hemagglutinin of the strain isolated in 2008 (taiwan08) had multibasic amino acid residues a ...201121301183
efficacy of avian influenza vaccine in poultry: a meta-analysis.vaccination is an effective method for controlling avian influenza (ai), especially in countries with endemic infection. this study conducted a bayesian meta-analysis to evaluate the efficacy of ai vaccines in chickens. we included both inactivated and recombinant fowlpox virus expressing h5 (rfpv-h5) vaccine studies that used specific-pathogen-free chickens where outcomes against the h5n1 or h5n2 ai viruses were measured. vaccine efficacy was evaluated by protection from mortality, protection f ...201021313840
[protective activity of immunovac-vp-4 vaccine against avian influenza virus h5n2 administered by different methods].to experimentally assess protective effect of immunovac-vp-4 vaccine against avian influenza virus h5n2. materials and methods. immunization of mice with polycomponent vaccine immunovac-vp-4 was performed using oral or mucosal route of administration (intranasally, orally, and with combined nasal-oral method). immunized mice were inoculated intranasally by influenza virus h5n2 adapted for mice. survival of mice in experimental and control (intact) groups was assessed daily during 14 days. surviv ...201121446167
unusual h5n2 avian influenza virus escapes current detection. 201121471334
transmission of avian influenza a viruses among species in an artificial barnyard.waterfowl and shorebirds harbor and shed all hemagglutinin and neuraminidase subtypes of influenza a viruses and interact in nature with a broad range of other avian and mammalian species to which they might transmit such viruses. estimating the efficiency and importance of such cross-species transmission using epidemiological approaches is difficult. we therefore addressed this question by studying transmission of low pathogenic h5 and h7 viruses from infected ducks to other common animals in a ...201121483843
avian influenza mucosal vaccination in chickens with replication-defective recombinant adenovirus vaccine.we evaluated protection conferred by mucosal vaccination with replication-competent adenovirus-free recombinant adenovirus expressing a codon-optimized avian influenza (ai) h5 gene from a/turkey/wi/68 (adtw68.h5ck). commercial, layer-type chicken groups were either singly vaccinated ocularly at 5 days of age, singly vaccinated via spray at 5 days of age, or ocularly primed at 5 days and ocularly boosted at 15 days of age. only chickens primed and boosted via the ocular route developed ai systemi ...201121500634
the adjuvant effect of sophy beta-glucan to the antibody response in poultry immunized by the avian influenza a h5n1 and h5n2 vaccines.avian influenza virus vaccines produced in oil-emulsified inactivated form with antigen content of at least 160 hemagglutinin units (hau) induced immunity in birds. however, in addition to enhancing the effect of the adjuvant(s), other additional supplemented biological compounds included in inactivated vaccines could produce higher levels of antibody. we examined in chickens, vietnamese ducks, and muscovy ducks the adjuvant effect of sophy beta-glucan (sbg), a beta-1,3-1,6 glucan produced by th ...201121532325
immunoadjuvant efficacy of plasmids with multiple copies of a cpg motif coadministrated with avian influenza vaccine in chickens.unmethylated cpg motifs are capable of evoking a range of immunostimulatory effects in vertebrates and have tremendous potential to be used as therapeutic agents and adjuvants. this particular type of cpg motif has been demonstrated to be an excellent immune adjuvant mediated by toll-like receptor 9 (tlr9) in various mammalian vaccines; however, only a few studies confirm its efficacy in avian vaccines. in the present study, immunomodulatory activities of plasmids with various copy numbers of a ...201121557981
[use of plant-origin components in roller cultivation of vaccine reassortant influenza virus strain h5n2].to study the optimal conditions for roller cultivation of cold-adapted reassortant vaccine strain of influenza virus a/17/duck/ potsdam/86/92 (h5n2) in mdck and vero cell cultures grown on nutrient medium based on soy and rice flour hydrolysates obtained using trypsin and bromeline.201121598624
complete protection against a h5n2 avian influenza virus by a dna vaccine expressing a fusion protein of h1n1 ha and m2e.most influenza vaccines target hemagglutinin (ha) in order to protect the host against infection. however, theses vaccines are strain-specific due to major antigenic variations of ha. since it is difficult to predict epidemic and pandemic strains of influenza virus, the development of effective vaccines against divergent influenza viruses is urgently needed. although m2e-based vaccines are associated with weaker protection than ha-based vaccines that induce neutralizing antibodies against challe ...201121664216
development of influenza vaccine production capacity by the government pharmaceutical organization of thailand: addressing the threat of an influenza pandemic.in 2005, a year after highly pathogenic avian influenza outbreaks in thailand, the thai government issued a national strategy plan for pandemic influenza preparedness, a major objective of which was the domestic production of seasonal influenza vaccine. it was considered that sustained influenza vaccine production was the best guarantee of a pandemic vaccine in the event of a future pandemic. the government decided to provide funds to establish an industrial-scale influenza vaccine production pl ...201121684425
expression of duck ccl19 and ccl21 and ccr7 receptor in lymphoid and influenza-infected tissues.ducks are the natural host and reservoir of influenza viruses. we are interested in their immune responses to these viruses, to understand host-pathogen interactions and to develop effective agricultural vaccines. we identified duck homologues of the chemokines ccl19 and ccl21 and cloned their cognate receptor, ccr7. conservation of key features, and expression in lymphoid tissues suggests that these chemokines are the direct orthologues of their mammalian counterparts. mammalian ccl19 and ccl21 ...201121704378
avian influenza viruses infect primary human bronchial epithelial cells unconstrained by sialic acid +¦2,3 residues.avian influenza viruses (aiv) are an important emerging threat to public health. it is thought that sialic acid (sia) receptors are barriers in cross-species transmission where the binding preferences of aiv and human influenza viruses are sias +¦2,3 versus +¦2,6, respectively. in this study, we show that a normal fully differentiated, primary human bronchial epithelial cell model is readily infected by low pathogenic h5n1, h5n2 and h5n3 aiv, which primarily bind to sia +¦2,3 moieties, and repli ...201121731666
measurement of enzymatic activity and specificity of human and avian influenza neuraminidases from whole virus by glycoarray and maldi-tof mass spectrometry.influenza neuraminidases hydrolyze the ketosidic linkage between n-acetylneuraminic acid and its adjacent galactose residue in sialosides. this enzyme is a tetrameric protein that plays a critical role in the release of progeny virions. several methods have been described for the determination of neuraminidase activity, usually based on colorimetric, fluorescent, or chemiluminescent detection. however, only a few of these tests allow discrimination of the sialyl-linkage specificity (i.e., α2-3- ...201121739555
thermal inactivation of avian influenza virus and newcastle disease virus in a fat-free egg product.high-pathogenicity avian influenza (hpai) virus, low-pathogenicity avian influenza (lpai) virus, virulent newcastle disease virus (vndv) and low-virulent newcastle disease virus (lndv) can be present on the eggshell surface, and hpai viruses and vndv can be present in the internal contents of chicken eggs laid by infected hens. with the increase in global trade, egg products could present potential biosecurity problems and affect international trade in liquid and dried egg products. therefore, t ...201121740719
multiple dose vaccination with heterologous h5n2 vaccine: immune response and protection against variant clade 2.2.1 highly pathogenic avian influenza h5n1 in broiler breeder chickens.circulation of an antigenically variant lineage of highly pathogenic avian influenza (hpai) h5n1 virus in chicken breeder flocks in egypt is a continuing problem. the protective efficacy of multiple repeated vaccinations using the currently available h5n2 vaccines is unclear. here, broiler breeder chickens were vaccinated at weeks 6, 12 and 18 with an inactivated h5n2 commercial vaccine. hi-titer against an egyptian h5n1 field isolate of classic clade 2.2.1 (egycls/h5n1) were significantly lower ...201121745517
humoral antibody responses to different h5n1 and h5n2 vaccination regimes: implications for the development of autogenously based vaccines.whereas h5n1 vaccine and several h5n2 vaccines are commercially available and are used to control h5n1 outbreaks in some endemic countries, infections hit many vaccinated flocks. the following study was conducted to compare the efficacy of such vaccines and to assess their potential induction of antibodies against the haemagglutinin of local h5n1 isolate after single vaccination. the possible beneficiary effect of booster dose at different intervals was screened for both h5n1 vaccine as well as ...201121752557
[immunogenicity of influenza virus h5n2 vaccine strain samples produced by roller cultivation in media with plant derived components].study in cba line mice of immunogenicity of cold adapted reassortant influenza virus h5n2 vaccine strain samples produced in rollers in mdck and vero cell cultures by using plant derived components.201121812141
memory t-cell immune response in healthy young adults vaccinated with live attenuated influenza a(h5n2) vaccine.cellular immune responses of both cd4 and cd8 memory/effector t cells were evaluated in healthy young adults who received two doses of live attenuated influenza a(h5n2) vaccine. the vaccine was developed by reassortment of non-pathogenic avian a/duck/potsdam/1402-6/68 (h5n2) and cold-adapted a/leningrad/134/17/57 (h2n2) viruses. t-cell responses were measured by standard methods of intracellular cytokine staining of ifnγ-producing cells and a novel trap-assay based on the trogocytosis phenomenon ...201121813657
evaluation study of a portable impedance biosensor for detection of avian influenza virus.current methods for detection of avian influenza virus (aiv) based on virus culture and rt-pcr are well established, but they are either time consuming or require specialized laboratory facilities and highly trained technicians. a simple, rapid, robust, and reliable test, suitable for use in the field or at the patient's bedside, is urgently needed. in this study, the performance of a newly developed portable impedance biosensor was evaluated by comparison with real-time reverse transcriptase pc ...201121872621
[evaluation of immunogenicity and safety of 2 immunizations with allantoic intranasal live influenza vaccine ultragrivac].evaluate reactogenicity, safety and immunogenicity in phase 2 clinical trials of 2 immunization schedules with ultragrivac--an allantoic intranasal life influenza vaccine based on a/17/ duck/potsdam/86/92 [17/h5] reassortant strain.201121916043
Influence of maternal immunity on vaccine efficacy and susceptibility of one day old chicks against Egyptian highly pathogenic avian influenza H5N1.In Egypt, continuous circulation of highly pathogenic avian influenza (HPAI) H5N1 viruses of clade 2.2.1 in vaccinated commercial poultry challenges strenuous control efforts. Here, vaccine-derived maternal AIV H5 specific immunity in one-day old chicks was investigated as a factor of vaccine failure in long-term blanket vaccination campaigns in broiler chickens. H5 seropositive one-day old chicks were derived from breeders repeatedly immunized with a commercial inactivated vaccine based on the ...201121920677
influenza-a viruses in ducks in northwestern minnesota: fine scale spatial and temporal variation in prevalence and subtype diversity.waterfowl from northwestern minnesota were sampled by cloacal swabbing for avian influenza virus (aiv) from july-october in 2007 and 2008. aiv was detected in 222 (9.1%) of 2,441 ducks in 2007 and in 438 (17.9%) of 2,452 ducks in 2008. prevalence of aiv peaked in late summer. we detected 27 aiv subtypes during 2007 and 31 during 2008. ten hemagglutinin (ha) subtypes were detected each year (i.e., h1, 3-8, and 10-12 during 2007; h1-8, 10 and 11 during 2008). all neuraminidase (na) subtypes were d ...201121931636
Coexpression of avian influenza virus H5 and N1 by recombinant Newcastle disease virus and the impact on immune response in chickens.To analyze the contribution of neuraminidase (NA) toward protection against avian influenza virus (AIV) infection, three different recombinant Newcastle disease viruses (NDVs) expressing hemagglutinin (HA) or NA, or both, of highly pathogenic avian influenza virus (HPAIV) were generated. The lentogenic NDV Clone 30 was used as backbone for the insertion of HA of HPAIV strain A/chicken/Vietnam/P41/05 (H5N1) and NA of HPAIV strain A/duck/Vietnam/TG24-01/05 (H5N1). The HA was inserted between the g ...201122017039
Genetic characterization of a novel influenza A virus H5N2 isolated from a dog in China.An influenza virus, A/canine/Shandong/JT01/2009, has been isolated from a dog exhibiting classical flu signs in China. HAI and NAI assays subtyped A/canine/Shandong/JT01/2009 as a H5N2 like virus. Phylogenetic reconstructions indicated strong relationships with viruses from various hosts and dispersed geographic locations. These analyses indicate A/canine/Shandong/JT01/2009 is a novel virus generated by complex reassortment of the viral segments.201122033043
rapid and specific influenza virus detection by functionalized magnetic nanoparticles and mass spectrometry.abstract:201122088100
Isolation, identification, and phylogenetic analysis of reassortant low-pathogenic avian influenza virus H3N1 from Pakistan.During routine avian influenza surveillance in Pakistan, a low-pathogenic avian influenza virus (LPAI) subtype H3N1 was isolated for the first time from domestic chickens. The higher seroprevalence of H3N1 was recorded in both commercial and domestic poultry in ecological zones of Pakistan where the geographical proximity with neighboring countries and attractive birding sites provide better opportunities for frequent movements of wild and migratory birds, and their intermingling with the local ...201222184438
development of a recombinant elisa using yeast (pichia pastoris)-expressed polypeptides for detection of antibodies against avian influenza a subtype h5.two truncated sequences (designated p1 and rha1) of influenza a virus subtype h5 haemagglutinin (ha) were cloned and expressed in yeast pichia pastoris (p. pastoris). these polypeptides were used in an indirect recombinant elisa (relisa) for detection of h5 antibodies in poultry. serum samples obtained from broiler chickens vaccinated with commercial inactivated vaccine (h5n2) and control negative sera from non-vaccinated chickens against influenza were tested using rp1-elisa, rha1-elisa, whole ...201122197190
salmonella flagellin enhances mucosal immunity of avian influenza vaccine in chickens.flagellin, a bioactive toll-like receptor (tlr) 5 ligand, may trigger the innate immunity that in turn is important for subsequent adaptive immune responses. in the present study, the adjuvant effects of the monomeric and polymeric forms of salmonella flagellin (mflic and pflic, respectively) were examined in specific-pathogen free (spf) chickens immunized intramuscularly (i.m.) or intranasally (i.n.) with formalin-inactivated avian influenza virus (aiv) h5n2 vaccines. results showed that mflic ...201122226542
cloned cdna of a/swine/iowa/15/1930 internal genes as a candidate backbone for reverse genetics vaccine against influenza a viruses.reverse genetics viruses for influenza vaccine production usually utilize the internal genes of the egg-adapted a/puerto rico/8/34 (pr8) strain. this egg-adapted strain provides high production yield in embryonated eggs but does not necessarily give the best yield in mammalian cell culture. in order to generate a reverse genetics viral backbone that is well-adapted to high growth in mammalian cell culture, a swine influenza isolate a/swine/iowa/15/30 (h1n1) (rg1930) that was shown to give high y ...201222230579
distribution of avian influenza h5n1 viral rna in tissues of ai-vaccinated and unvaccinated contact chickens after experimental infection.avian influenza due to highly pathogenic avian influenza (hpaiv) h5n1 virus is not a food-borne illness but a serious panzootic disease with the potential to be pandemic. in this study, broiler chickens were vaccinated with commercial h5n1 or h5n2 inactivated vaccines prior to being challenged with an hpaiv h5n1 (clade 2.2.1 classic) virus. challenged and non-challenged vaccinated chickens were kept together, and unvaccinated chickens served as contact groups. post-challenge samples from skin an ...201222350650
[the generation and characteristics of reassortant influenza a virus with h5 hemagglutinin and other genes from the apathogenic virus h6n2].the experimental reassortant vaccine strain vn-gull (h5n2) containing h5 hemagglutinin (ha) with a removed polybasic site in the connecting peptide and other genes from the apathogenic h6n2 virus a/gull/moscow/3100/2006 (gull/m) was obtained using a two-step protocol. at step 1, the reassortant with ha of a/vietnam/1203/04-pr8/ cdc-rg and other genes from cold-adapted a/leningrad/17/47 (vn-len) viruses was generated due to selection with antibody to h2n2 at 26 degrees c. at step 2, the reassorta ...201122359942
vaccination and acute phase mediator production in chickens challenged with low pathogenic avian influenza virus; novel markers for vaccine efficacy?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 quantify viral shedding after challenge, but it is time and labor intensive. therefore, we sought alternative methods to demonstrate vaccine efficacy, and examined whether vaccination of chickens affected ...201222394994
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