David E Swayne

Erasmus MC, Rotterdam, South Holland, Netherlands

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Publications (272)933.09 Total impact

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    ABSTRACT: H7N9 influenza A first caused human infections in early 2013 in China. Virus genetics, histories of patient exposures to poultry, and previous experimental studies suggest the source of the virus is a domestic avian species, such as chickens. In order to better understand the ecology of this H7N9 in chickens, we evaluated the infectious dose and pathogenesis of A/Anhui/1/2013 H7N9 in two common breeds of chickens, White Leghorns (table-egg layers) and White Plymouth Rocks (meat chickens). No morbidity or mortality were observed with doses of 106 or 108 EID50/bird when administered by the upper-respiratory route, and the mean infectious dose (106 EID50) was higher than expected, suggesting that the virus is poorly adapted to chickens. Virus was shed at higher titers and spread to the kidneys in chickens inoculated by the intravenous route. Challenge experiments with three other human-origin H7N9 viruses showed a similar pattern of virus replication.
    Virology 03/2015; 477. DOI:10.1016/j.virol.2015.01.013 · 3.28 Impact Factor
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    ABSTRACT: Infections with avian influenza viruses (AIV) of low and high pathogenicity (LP and HP) and Newcastle disease virus (NDV) are commonly reported in domestic ducks in many parts of the world. However, it is not clear if co-infections with these viruses affect the severity of the diseases they produce, the amount of virus shed, and transmission of the viruses. In this study we infected domestic ducks with a virulent NDV virus (vNDV) and either a LPAIV or a HPAIV by giving the viruses individually, simultaneously, or sequentially two days apart. No clinical signs were observed in ducks infected or co-infected with vNDV and LPAIV, but co-infection decreased the number of ducks shedding vNDV and the amount of virus shed (P<0.01) at 4 days post inoculation (dpi). Co-infection did not affect the number of birds shedding LPAIV, but more LPAIV was shed at 2dpi (P<0.0001) from ducks inoculated with only LPAIV compared to ducks co-infected with vNDV. Ducks that received the HPAIV with the vNDV simultaneously survived fewer days (P<0.05) compared to the ducks that received the vNDV two days before the HPAIV. Co-infection also reduced transmission of vNDV to naïve contact ducks housed with the inoculated ducks. In conclusion, domestic ducks can become co-infected with vNDV and LPAIV with no effect on clinical signs but with reduction of virus shedding and transmission. These findings indicate that infection with one virus can interfere with replication of another, modifying the pathogenesis and transmission of the viruses. Published by Elsevier B.V.
    Veterinary Microbiology 02/2015; DOI:10.1016/j.vetmic.2015.02.008 · 2.73 Impact Factor
  • Kateri Bertran, Kira Moresco, David E Swayne
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    ABSTRACT: High pathogenicity avian influenza virus (HPAIV) infections in chickens negatively impact egg production and cause egg contamination. Previously, vaccination maintained egg production and reduced egg contamination when challenged with a North American H5N2 HPAIV. However, Asian H5N1 HPAIV infection has some characteristics of increased pathogenicity compared to other H5 HPAIV such as more rapid drop and complete cessation in egg production. Sham (vaccinated at 25 and 28 weeks of age), inactivated H5N1 Once (1X-H5-Vax; vaccinated at 28 weeks of age only) and inactivated H5N1 Twice (2X-H5-Vax; vaccinated at 25 and 28 weeks of age) vaccinated adult White Leghorn hens were challenged intranasally at 31 weeks of age with 6.1 log10 mean embryo infectious doses (EID50) of clade H5N1 HPAIV (A/chicken/Vietnam/NCVD-675/2011) which was homologous to the inactivated vaccine. Sham-vaccinated layers experienced 100% mortality within 3 days post-challenge; laid soft and thin-shelled eggs; had recovery of virus from oral swabs and in 53% of the eggs from eggshell surface (35%), yolk (24%), and albumin (41%); and had very high titers of virus (average 7.91 log10 EID50/g) in all segments of the oviduct and ovary. By comparison, 1X- and 2X-H5-Vax challenged hens survived infection, laid similar number of eggs pre- and post-challenge, all eggs had normal egg shell quality, and had significantly fewer contaminated eggs with reduced virus quantity. The 2X-H5-Vax hens had significantly higher HI titers by the day of challenge (304 GMT) and at termination (512 GMT) than 1X-H5-Vax hens (45 GMT and 128 GMT). The current study demonstrated that AIV infections caused by clade H5N1 variants can be effectively controlled by either double or single homologous vaccination. Copyright © 2015. Published by Elsevier Ltd.
    Vaccine 02/2015; 33(11). DOI:10.1016/j.vaccine.2015.01.055 · 3.49 Impact Factor
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    ABSTRACT: Vaccines are used in integrated control strategies to protect poultry against H5N1 high pathogenicity avian influenza (HPAI). H5N1 HPAI was first reported in Indonesia in 2003 and vaccination was initiated in 2004, but reports of vaccine failures began to emerge in mid-2005. This study investigated the role of Indonesian licensed vaccines, specific vaccine seed strains and emerging variant field viruses as causes of vaccine failures. Eleven of 14 licensed vaccines contained the manufacturer's listed vaccine seed strains, but three vaccines contained a different seed strain than listed on the label. Vaccines containing A/turkey/Wisconsin/1968 (WI/68), A/chicken/Mexico/28159-232/1994 (Mex/94) and Eng/73 seed strains had high serological potency in chickens (geometric mean HI titers ≥ 1:169), but vaccines containing reverse genetic (rg) A/chicken/Guangdong/1/1996 (rgGD/96), A/chicken/Legok/2003 (Legok/03), rgA/chicken/Vietnam/C57/2004 (rgVN/04) or rgA/chicken/Legok/2003 (rgLegok/03) had lower serological potency (geometric mean HI titers ≤ 1:95). In challenge studies, chickens immunized with any of the H5 AI vaccines were protected against A/chicken/West Java/SMI-HAMD/2006 (SMI-HAMD/06), partially protected against A/chicken/Papua/TA5/2006 (Papua/06), but were not protected against A/chicken/West Java/PWT-WIJ/2006 (PWT/06). Experimental inactivated vaccines made with PWT/06 HPAI or rgPWT/06 LPAI seed strains protected chickens from lethal challenge as did a combination of a commercially available live fowl poxvirus vaccine expressing the H5 influenza gene and inactivated Legok/03 vaccine. These studies indicate that antigenic variants did emerge in Indonesia following widespread H5 avian influenza vaccine usage, and efficacious inactivated vaccines can be developed using antigenic variant wild type viruses or rgLPAI seed strains containing hemagglutinin and neuraminidase genes of wild type viruses. H5N1 high pathogenicity avian influenza (HPAI) has become endemic in Indonesian poultry and such poultry are the source of virus for birds and mammals including humans. Vaccination has become a part of the poultry control strategy but vaccine failures have occurred in the field. This study identified possible causes of vaccine failure which included use of an unlicensed virus seed strain and induction of low levels of protective antibody because of insufficient quantity of vaccine antigen. However, the most important cause of vaccine failure was the appearance of drift variant field viruses that partially or completely overcome commercial vaccine induced immunity. Furthermore, experimental vaccines using inactivated wild type or reverse genetic generated vaccines containing hemagglutinin and neuraminidase genes of wild type drift variant field viruses were protective. These studies indicate the need for surveillance to identify drift variant viruses in the field and update licensed vaccines when such variants appear. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
    Journal of Virology 01/2015; 89(7). DOI:10.1128/JVI.00025-15 · 4.65 Impact Factor
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    ABSTRACT: Inactivated and fowlpox virus (FP)-vectored vaccines have been used to control H5 avian influenza (AI) in poultry. In H5 AI endemic countries, breeder flocks are vaccinated and therefore, maternally-derived antibodies (MDA) are transferred to their progeny. Results of three immunogenicity and one efficacy studies performed in birds with or without MDA indicated that the immunogenicity of an inactivated vaccine based on a H5N9 AI isolate (inH5N9) was severely impaired in chicks hatched from inH5N9-vaccinated breeders. This MDA interference was lower when breeders received only one administration of the same vaccine and could be overcome by priming the chicks at day-of-age with a live recombinant FP-vectored vaccine with H5 avian influenza gene insert (FP-AI). The interference of anti-FP MDA was of lower intensity than the interference of anti-AI MDA. The highest interference observed on the prime-boost immunogenicity was in chicks hatched from breeders vaccinated with the same prime-boost scheme. The level of protection against an antigenic variant H5N1 highly pathogenic AI isolate from Indonesia against which the FP-AI or inH5N9 alone was poorly protective could be circumvented by the prime-boost regimen in birds with either FP or AI MDA. Thus, the immunogenicity of vaccines in young chicks with MDA depends on the vaccination scheme and the type of vaccine used in their parent flocks. The heterologous prime-boost in birds with MDA may at least partially overcome MDA interference on inactivated vaccine.
    Veterinary Research 10/2014; 45(1):107. DOI:10.1186/PREACCEPT-3462105181282326 · 3.38 Impact Factor
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    ABSTRACT: Background Highly pathogenic (HP) H5N1 avian influenza virus (AIV) was introduced to Egyptian poultry in 2006 and has since become enzootic. Vaccination has been utilized as a control tool combined with other control methods, but for a variety of reasons, the disease has not been eradicated. In 2007, an antigenically divergent hemagglutinin subclade,, emerged from the original clade 2.2.1 viruses.Objectives The objective was to evaluate four diverse AIV isolates for use as vaccines in chickens, including two commercial vaccines and two additional contemporary isolates, against challenge with numerous clade 2.2.1 and clade H5N1 HPAIV Egyptian isolates to assess the variation in protection among different vaccine and challenge virus combinations.Methods Vaccination-challenge studies with four vaccines and up to eight challenge strains with each vaccine for a total of 25 vaccination-challenge groups were conducted with chickens. An additional eight groups served as sham-vaccinated controls. Mortality, mean death time, morbidity, virus, and pre-challenge antibodies were evaluated as metrics of protection. Hemagglutination inhibition data were used to visualize the antigenic relatedness of the isolates.Results and conclusionsAlthough all but one vaccine-challenge virus combination significantly reduced shed and mortality as compared to sham vaccinates, there were differences in protection among the vaccines relative to one another based on challenge virus. This emphasizes the difficulty in vaccinating against diverse, evolving virus populations, and the importance of selecting optimal vaccine seed strains for successful HPAIV control.
    Influenza and Other Respiratory Viruses 10/2014; DOI:10.1111/irv.12290 · 1.47 Impact Factor
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    ABSTRACT: In the spring of 2012 an outbreak of H7N3 highly pathogenic (HP) avian influenza virus (AIV) occurred in poultry in Mexico. Vaccination was implemented as a control measure, along with increased biosecurity and surveillance. At that time there was no commercially available H7 AIV vaccine in North America; therefore, a recent H7N3 wild bird isolate of low pathogenicity from Mexico (A/cinnamon teal/Mexico/2817/2006 H7N3) was selected and utilized as the vaccine seed strain. In these studies, the potency and efficacy of this vaccine strain was evaluated in chickens against challenge with the 2012 Jalisco H7N3 HPAIV. Although vaccine doses of 256 and 102 hemagglutinating units (HAU) per bird decreased morbidity and mortality significantly compared to sham vaccinates, a dose of 512 HAU per bird was required to prevent mortality and morbidity completely. Additionally, the efficacy of 11 other H7 AIV vaccines and an antigenic map of hemagglutination inhibition assay data with all the vaccines and challenge viruses were evaluated, both to identify other potential vaccine strains and to characterize the relationship between genetic and antigenic distance with protection against this HPAIV. Several other isolates provided adequate protection against the 2012 Jalisco H7N3 lineage, but antigenic and genetic differences were not clear indicators of protection because the immunogenicity of the vaccine seed strain was also a critical factor.
    Avian Diseases 09/2014; 58(3):359-66. DOI:10.1637/10751-121913-Reg.1 · 1.11 Impact Factor
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    ABSTRACT: Aquatic habitats play a critical role in the transmission and maintenance of low-pathogenic avian influenza (LPAI) viruses in wild waterfowl; however, the importance of these environments in the ecology of H5N1 highly pathogenic avian influenza (HPAI) viruses is unknown. In laboratory-based studies, LPAI viruses can remain infective for extended durations (months) in water, but the persistence is strongly dependent on water conditions (temperature, salinity, pH) and virus strain. Little is known about the stability of H5N1 HPAI viruses in water. With the use of an established laboratory model system, the persistence of 11 strains of H5N1 HPAI virus was measured in buffered distilled water (pH 7.2) at two temperatures (17 and 28 C) and three salinities (0, 15,000, and 30,000 ppm). There was extensive variation between the 11 H5N1 HPAI virus strains in the overall stability in water, with a range similar to that which has been reported for wild-bird-origin LPAI viruses. The H5N1 HPAI virus strains responded similarly to different water temperatures and salinities, with all viruses being most stable at colder temperatures and fresh to brackish salinities. These results indicate that the overall stability and response of H5N1 HPAI viruses in water is similar to LPAI viruses, and suggest there has been no increase or loss of environmental survivability in H5N1 HPAI viruses.
    Avian Diseases 09/2014; 58(3):453-7. DOI:10.1637/10741-120513-ResNote.1 · 1.11 Impact Factor
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    ABSTRACT: Modulating the host response is a promising approach to treating influenza, a virus whose pathogenesis is determined in part by the reaction it elicits within the host. Though the pathogenicity of emerging H7N9 influenza virus has been reported in several animal models, these studies have not included a detailed characterization of the host response following infection. To this end, we characterized the transcriptomic response of BALB/c mice infected with H7N9 (A/Anhui/01/2013) virus and compared it to the responses induced by H5N1 (A/Vietnam/1203/2004), H7N7 (A/Netherlands/219/2003) or pandemic 2009 H1N1 (A/Mexico/4482/2009) influenza viruses. We found that responses to the H7 subtype viruses were intermediate to those elicited by H5N1 and pdm09H1N1 early in infection, but that they evolved to resemble the H5N1 response as infection progressed. H5N1, H7N7 and H7N9 viruses were pathogenic in mice, and this pathogenicity correlated with increased transcription of cytokine response genes and decreased transcription of lipid metabolism and coagulation signaling genes. This three-pronged transcriptomic signature was observed in mice infected with pathogenic H1N1 strains such as the 1918 virus, indicating that it may be predictive of pathogenicity across multiple influenza strains. Finally, we used host transcriptomic profiling to computationally predict drugs that reverse the host response to H7N9 infection, and identified six FDA-approved drugs that could potentially be repurposed to treat H7N9 and other pathogenic influenza viruses.
    Journal of Virology 07/2014; 88(18). DOI:10.1128/JVI.00570-14 · 4.65 Impact Factor
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    Kateri Bertran, David E Swayne
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    ABSTRACT: 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 strain. In addition, H5N1 HPAIV produced higher titers in the meat of infected chickens and more easily infected ferrets than the H7N3 or H7N7 HPAIV.
    Veterinary Research 06/2014; 45(1):60. DOI:10.1186/1297-9716-45-60 · 3.38 Impact Factor
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    ABSTRACT: Double reassortant H13N8 influenza A virus was isolated from gull in Mongolia. The basic virological characteristics were studied. Complete genome sequence analysis indicated the complicated evolutionary history. The PA gene belongs to classical Avian-like lineage and more likely originated from non-gull avian virus pool. Data confirm the state of extensive geographic mosaicism in AIV from gulls in the Northern Hemisphere.
    Virus Genes 05/2014; DOI:10.1007/s11262-014-1083-7 · 1.84 Impact Factor
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    ABSTRACT: The recent outbreak of H7N9 influenza in China has resulted in many human cases with a high fatality rate. Poultry are the likely source of infection for humans on the basis of sequence analysis and virus isolations from live bird markets, but it is not clear which species of birds are most likely to be infected and shedding levels of virus sufficient to infect humans. Intranasal inoculation of chickens, Japanese quail, pigeons, Pekin ducks, Mallard ducks, Muscovy ducks, and Embden geese with 106 50% egg infective doses of the A/Anhui/1/2013 virus resulted in infection but no clinical disease signs. Virus shedding was much higher and prolonged in quail and chickens than in the other species. Quail effectively transmitted the virus to direct contacts, but pigeons and Pekin ducks did not. In all species, virus was detected at much higher titers from oropharyngeal swabs than cloacal swabs. The hemagglutinin gene from samples collected from selected experimentally infected birds was sequenced, and three amino acid differences were commonly observed when the sequence was compared to the sequence of A/Anhui/1/2013: N123D, N149D, and L217Q. Leucine at position 217 is highly conserved for human isolates and is associated with alpha 2,6-sialic acid binding. Different amino acid combinations were observed, suggesting that the inoculum had viral subpopulations that were selected after passage in birds. These experimental studies corroborate the finding that certain poultry species are reservoirs of the H7N9 influenza virus and that the virus is highly tropic for the upper respiratory tract, so testing of bird species should preferentially be conducted with oropharyngeal swabs for the best sensitivity.
    Journal of Virology 02/2014; 88(10). DOI:10.1128/JVI.03689-13 · 4.65 Impact Factor
  • David E Swayne
    Expert Review of Vaccines 01/2014; 11(8). DOI:10.1586/erv.12.60 · 4.22 Impact Factor
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    ABSTRACT: Low pathogenicity avian influenza virus (LPAIV) and lentogenic Newcastle disease virus (lNDV) are commonly reported causes of respiratory disease in poultry worldwide with similar clinical and pathobiological presentation. Co-infections do occur but are not easily detected, and the impact of co-infections on pathobiology is unknown. In this study chickens and turkeys were infected with a lNDV vaccine strain (LaSota) and a H7N2 LPAIV (A/turkey/VA/SEP-67/2002) simultaneously or sequentially three days apart. No clinical signs were observed in chickens co-infected with the lNDV and LPAIV or in chickens infected with the viruses individually. However, the pattern of virus shed was different with co-infected chickens, which excreted lower titers of lNDV and LPAIV at 2 and 3 days post inoculation (dpi) and higher titers at subsequent time points. All turkeys inoculated with the LPAIV, whether or not they were exposed to lNDV, presented mild clinical signs. Co-infection effects were more pronounced in turkeys than in chickens with reduction in the number of birds shedding virus and in virus titers, especially when LPAIV was followed by lNDV. In conclusion, co-infection of chickens or turkeys with lNDV and LPAIV affected the replication dynamics of these viruses but did not affect clinical signs. The effect on virus replication was different depending on the species and on the time of infection. These results suggest that infection with a heterologous virus may result in temporary competition for cell receptors or competent cells for replication, most likely interferon-mediated, which decreases with time.
    Veterinary Research 01/2014; 45(1):1. DOI:10.1186/1297-9716-45-1 · 3.38 Impact Factor
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    ABSTRACT: 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. To study safety, immunogenicity and protection of H7N3 LAIV candidate in mice, ferrets and chickens. The vaccine was generated by a classical reassortment between low pathogenicity A/mallard/Netherlands/00 (H7N3) virus and A/Leningrad4/17/57 (H2N2) master donor virus (MDV). Immunogenicity was found that H7N3 LAIV was similar to the MDV in terms of replication in the respiratory organs of mice and failed to replicate in mouse brains. One dose of a H7N3 LAIV elicited measurable antibody response and it was further boosted with a second vaccine dose. Immunization of mice with H7N3 LAIV provided protection against infection following a homologous challenge with wild type H7N3 virus. Attenuated phenotype of H7N3 LAIV has been confirmed in ferrets. Immunogenicity and protective efficacy of H7N3 LAIV in ferrets were also demonstrated. The vaccine protected animals from subsequent infection with wild type H7N3 virus. The results of histopathology study revealed that inoculation of H7N3 LAIV in ferrets did not cause any inflammation or destructive changes in lungs. Lack of H7N3 LAIV replication in chicken demonstrated complete safety of this preparation for poultry. Results of our study suggest that new H7N3 LAIV candidate is safe, immunogenic and protects from homologues influenza virus infection in mice and ferrets.
  • David E Swayne
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    ABSTRACT: Avian influenza vaccines for poultry are based on hemagglutinin proteins, and protection is specific to the vaccine subtype. Over 113 billion doses have been used between 2002 and 2010 for high pathogenicity avian influenza control. No universal vaccines are currently available. The majority of avian influenza vaccines are inactivated whole influenza viruses that are grown in embryonating eggs, inactivated, emulsified in oil adjuvant systems, and injected into chickens. Live virus-vectored vaccines such as recombinant viruses of fowl pox, Newcastle disease, herpesvirus of turkeys and duck enteritis containing inserts of avian influenza virus hemagglutinin genes have been used on a more limited basis. In studies to evaluate vaccine efficacy and potency, the protocol design and its implementation should address the biosafety level needed for the work, provide information required for approval by Institutional Biosafety and Animal Care Committees, contain information on seed strain selection, provide needed information on animal subjects and their relevant parameters, and address the selection and use of challenge viruses. Various metrics have been used to directly measure vaccine induced protection. These include prevention of death, clinical signs, and lesions; prevention of decreases in egg production and alterations in egg quality; quantification of the reduction in virus replication and shedding from the respiratory tract and gastrointestinal tracts; and prevention of contact transmission in in vivo poultry experiments. In addition, indirect measures of vaccine potency and protection can be developed and validated against the direct measures and include serological assays in vaccinated poultry and assessment of the content of hemagglutinin antigen in the vaccine. These indirect assessments of protection are useful in determining if vaccine batches have a consistent ability to protect. For adequate potency, vaccines should contain 50 mean protective doses of antigen, which corresponds to 0.3-7.8 μg of hemagglutinin protein, depending on immunogenicity of individual seed strains.
    Methods in molecular biology (Clifton, N.J.) 01/2014; 1161:185-198. DOI:10.1007/978-1-4939-0758-8_16 · 1.29 Impact Factor
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    ABSTRACT: Thirty-two epizootics of high pathogenicity avian influenza (HPAI) have been reported in poultry and other birds since 1959. The ongoing H5N1 HPAI epizootic that began in 1996 has also spilled over to infect wild birds. Traditional stamping-out programs in poultry have resulted in eradication of most HPAI epizootics. However, vaccination of poultry was added as a control tool in 1995 and has been used during five epizootics. Over 113 billion doses of AI vaccine have been used in poultry from 2002 to 2010 as oil-emulsified, inactivated whole AIV vaccines (95.5%) and live vectored vaccines (4.5%). Over 99% of the vaccine has been used in the four H5N1 HPAI enzootic countries: China including Hong Kong (91%), Egypt (4.7%), Indonesia (2.3%), and Vietnam (1.4%) where vaccination programs have been nationwide and routine to all poultry. Ten other countries used vaccine in poultry in a focused, risk-based manner but this accounted for less than 1% of the vaccine used. Most vaccine "failures" have resulted from problems in the vaccination process; i.e., failure to adequately administer the vaccine to at-risk poultry resulting in lack of population immunity, while fewer failures have resulted from antigenic drift of field viruses away from the vaccine viruses. It is currently not feasible to vaccinate wild birds against H5N1 HPAI, but naturally occurring infections with H5 low pathogenicity avian influenza viruses may generate cross-protective immunity against H5N1 HPAI. The most feasible method to prevent and control H5N1 HPAI in wild birds is through control of the disease in poultry with use of vaccine to reduce environmental burden of H5N1 HPAIV, and eventual eradication of the virus in domestic poultry, especially in domestic ducks which are raised in enzootic countries on range or in other outdoor systems having contact with wild aquatic and periurban terrestrial birds.
    EcoHealth 09/2013; 11(1). DOI:10.1007/s10393-013-0861-3 · 2.27 Impact Factor
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    ABSTRACT: Domestic ducks are the second most abundant poultry species in many Asian countries including Vietnam, and play a critical role in the epizootiology of H5N1 highly pathogenic avian influenza (HPAI) [FAO]. In this study, we examined the protective efficacy in ducks of two commercial H5N1 vaccines widely used in Vietnam; Re-1 containing A/goose/Guangdong/1/1996 hemagglutinin (HA) clade 0 antigens, and Re-5 containing A/duck/Anhui/1/2006 HA clade 2.3.4 antigens. Ducks received two doses of either vaccine at 7 and at 14 or 21 days of age followed by challenge at 30 days of age with viruses belonging to the HA clades 1.1,, and isolated between 2008 and 2011 in Vietnam. Ducks vaccinated with the Re-1 vaccine were protected after infection with the two H5N1 HPAI viruses isolated in 2008 (HA clades 1.1 and showing no mortality and limited virus shedding. The Re-1 and Re-5 vaccines conferred 90-100% protection against mortality after challenge with the 2010 H5N1 HPAI viruses (HA clade; but vaccinated ducks shed virus for more than 7 days after challenge. Similarly, the Re-1 and Re-5 vaccines only showed partial protection against the 2011 H5N1 HPAI viruses (HA clade and, with a high proportion of vaccinated ducks shedding virus for more than 10 days. Furthermore, 50% mortality was observed in ducks vaccinated with Re-1 and challenged with the virus. The HA proteins of the 2011 challenge viruses had the greatest number of amino acid differences from the two vaccines as compared to the viruses from 2008 and 2009, which correlates with the lesser protection observed with these viruses. These studies demonstrate the suboptimal protection conferred by the Re-1 and Re-5 commercial vaccines in ducks against H5N1 HPAI clade viruses, and underscore the importance of monitoring vaccine efficacy in the control of H5N1 HPAI in ducks.
    Vaccine 08/2013; DOI:10.1016/j.vaccine.2013.08.046 · 3.49 Impact Factor
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    ABSTRACT: H5N1 highly pathogenic avian influenza (HPAI) viruses continue to be a threat to poultry in many regions of the world. Domestic ducks have been recognized as one of the primary factors in the spread of H5N1 HPAI. In this study we examined the pathogenicity of H5N1 HPAI viruses in different species and breeds of domestic ducks and the effect of route of virus inoculation on the outcome of infection. We determined that the pathogenicity of H5N1 HPAI viruses varies between the two common farmed duck species, with Muscovy ducks (Cairina moschata) presenting more severe disease than various breeds of Anas platyrhynchos var. domestica ducks including Pekin, Mallard-type, Black Runners, Rouen, and Khaki Campbell ducks. We also found that Pekin and Muscovy ducks inoculated with two H5N1 HPAI viruses of different virulence, given by any one of three routes (intranasal, intracloacal, or intraocular), became infected with the viruses. Regardless of the route of inoculation, the outcome of infection was similar for each species but depended on the virulence of the virus used. Muscovy ducks showed more severe clinical signs and higher mortality than the Pekin ducks. In conclusion, domestic ducks are susceptible to H5N1 HPAI virus infection by different routes of exposure, but the presentation of the disease varied by virus strain and duck species. This information helps support the planning and implementation of H5N1 HPAI surveillance and control measures in countries with large domestic duck populations.
    Veterinary Research 07/2013; 44(1):62. DOI:10.1186/1297-9716-44-62 · 3.38 Impact Factor
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    ABSTRACT: In June of 2012, a H7N3 highly pathogenic avian influenza (HPAI) virus was identified as the cause of a severe disease outbreak in commercial laying chicken farms in Mexico. The purpose of this study was to characterize the Mexican 2012 H7N3 HPAI virus (A/chicken/Jalisco/CPA1/2012) and determine protection conferred against the virus by different H7 inactivated vaccines in chickens. Both adult and young chickens intranasally inoculated with the virus became infected and died between 2 and 4 days post inoculation. High virus titers and viral replication in many tissues was demonstrated at 2 days p.i. in infected birds. The Jalisco virus had high sequence similarity of greater than 97% to wild bird viruses from North America in all eight gene segments. The hemagglutinin gene of the virus contained a 24 nucleotide insert at the hemagglutinin cleavage site which had a 100% sequence identity to chicken 28s ribosomal RNA, suggesting the insert was non-homologous recombination with the host genome. For vaccine protection studies, both U.S. H7 low pathogenic (LP) AI viruses and a 2006 Mexican H7 LPAI virus were tested as antigen in experimental oil emulsion vaccines and injected into chickens three weeks prior to challenge. All H7 vaccines tested provided ≥90 % protection against clinical disease after challenge and decreased the number of birds shedding and the titers of viral shedding. This study demonstrates the pathological consequence of the 2012 Mexican lineage H7N3 HPAI infection of chickens and provides support for effective vaccination programs in poultry against this virus.
    Journal of Virology 06/2013; DOI:10.1128/JVI.00666-13 · 4.65 Impact Factor

Publication Stats

11k Citations
933.09 Total Impact Points


  • 2012–2013
    • Erasmus MC
      • Department of Virology
      Rotterdam, South Holland, Netherlands
  • 2001–2013
    • Agricultural Research Service
      ERV, Texas, United States
  • 1988–2013
    • University of Georgia
      • • College of Veterinary Medicine
      • • Department of Population Health
      • • Department of Veterinary Pathology
      Athens, GA, United States
  • 2011
    • Mount Sinai School of Medicine
      • Department of Microbiology
      Manhattan, NY, United States
    • Benaroya Research Institute
      Seattle, Washington, United States
  • 2010
    • National Institute of Allergy and Infectious Disease
      베서스다, Maryland, United States
    • University of Washington Seattle
      • Department of Microbiology
      Seattle, Washington, United States
    • National Veterinary Research Quarantine Service
      Sŏul, Seoul, South Korea
  • 2003–2010
    • State Research Center of Virology and Biotechnology VECTOR
      Novo-Nikolaevsk, Novosibirsk, Russia
    • National Institute of Allergy and Infectious Diseases
      Maryland, United States
  • 1998–2010
    • Centers for Disease Control and Prevention
      • Influenza Division
      Druid Hills, GA, United States
  • 2009
    • Institut Pasteur
      Lutetia Parisorum, Île-de-France, France
  • 2007–2009
    • The Ohio Environmental Protection Agency
      Columbus, Ohio, United States
    • University of Alaska Fairbanks
      Fairbanks, Alaska, United States
    • National Veterinary Laboratory
      Franklin Lakes, New Jersey, United States
  • 2008
    • University of Ibadan
      Ibadan, Oyo, Nigeria
  • 1999–2006
    • Georgia Poultry Laboratory Network
      Georgia, United States
  • 2004
    • Tuskegee University
      • Department of Veterinary Medicine
      Tuskegee, Alabama, United States
    • Armed Forces Institute of Pathology
      Ralalpindi, Punjab, Pakistan
  • 1996–2004
    • United States Department of Agriculture
      • Agricultural Research Service (ARS)
      Washington, D. C., DC, United States
  • 1989–1998
    • The Ohio State University
      • • Department of Veterinary Preventive Medicine
      • • Department of Veterinary Biosciences
      • • Ohio Agricultural Research and Development Center
      Columbus, Ohio, United States