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Prof. Dr. Christian Grund
Institute of Diagnostic Virology, Friedrich-Loeffler-Institute, German Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany

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0 Molecular Epidemiology
0 Pathogenesis
0 avian influenza
0 Influenza viruses
0 Diagnostic methodology

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Journal article
Published: 09 May 2021 in Viruses
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The main findings of the post-mortem examination of poultry infected with highly pathogenic avian influenza viruses (HPAIV) include necrotizing inflammation and viral antigen in multiple organs. The lesion profile displays marked variability, depending on viral subtype, strain, and host species. Therefore, in this study, a semiquantitative scoring system was developed to compare histopathological findings across a wide range of study conditions. Briefly, the severity of necrotizing lesions in brain, heart, lung, liver, kidney, pancreas, and/or lymphocytic depletion in the spleen is scored on an ordinal four-step scale (0 = unchanged, 1 = mild, 2 = moderate, 3 = severe), and the distribution of the viral antigen in parenchymal and endothelial cells is evaluated on a four-step scale (0 = none, 1 = focal, 2 = multifocal, 3 = diffuse). These scores are used for a meta-analysis of experimental infections with H7N7 and H5N8 (clade 2.3.4.4b) HPAIV in chickens, turkeys, and ducks. The meta-analysis highlights the rather unique endotheliotropism of these HPAIV in chickens and a more severe necrotizing encephalitis in H7N7-HPAIV-infected turkeys. In conclusion, the proposed scoring system can be used to condensate HPAIV-typical pathohistological findings into semiquantitative data, thus enabling systematic phenotyping of virus strains and their tissue tropism.

ACS Style

Maria Landmann; David Scheibner; Annika Graaf; Marcel Gischke; Susanne Koethe; Olanrewaju Fatola; Barbara Raddatz; Thomas Mettenleiter; Martin Beer; Christian Grund; Timm Harder; Elsayed Abdelwhab; Reiner Ulrich. A Semiquantitative Scoring System for Histopathological and Immunohistochemical Assessment of Lesions and Tissue Tropism in Avian Influenza. Viruses 2021, 13, 868 .

AMA Style

Maria Landmann, David Scheibner, Annika Graaf, Marcel Gischke, Susanne Koethe, Olanrewaju Fatola, Barbara Raddatz, Thomas Mettenleiter, Martin Beer, Christian Grund, Timm Harder, Elsayed Abdelwhab, Reiner Ulrich. A Semiquantitative Scoring System for Histopathological and Immunohistochemical Assessment of Lesions and Tissue Tropism in Avian Influenza. Viruses. 2021; 13 (5):868.

Chicago/Turabian Style

Maria Landmann; David Scheibner; Annika Graaf; Marcel Gischke; Susanne Koethe; Olanrewaju Fatola; Barbara Raddatz; Thomas Mettenleiter; Martin Beer; Christian Grund; Timm Harder; Elsayed Abdelwhab; Reiner Ulrich. 2021. "A Semiquantitative Scoring System for Histopathological and Immunohistochemical Assessment of Lesions and Tissue Tropism in Avian Influenza." Viruses 13, no. 5: 868.

Original article
Published: 06 May 2021 in Transboundary and Emerging Diseases
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Newcastle disease (ND), caused by avian orthoavulavirus type‐1 (NDV), is endemic in poultry in many regions of the world and causes continuing outbreaks in poultry populations. In the Middle East, genotype XXI, , used to be present in poultry in Egypt but has been replaced by genotype VII. We investigated whether virus evolution contributed to superseding and focused on the antigenic sites within the Hemagglutinin‐Neuraminidase (HN) spike protein. Full length sequences of an NDV genotype VII isolate currently circulating in Egypt was compared to a genotype XXI isolate that was present as co‐infection with vaccine type viruses (II) in a historical virus isolated in 2011. Amino acid differences in the HN glycoprotein for both XXI and VII viruses amounted to 11.7% and 11.9 %, respectively, compared to the La Sota vaccine type. However, mutations within the globular head (aa 126‐570), bearing relevant antigenic sites, were underrepresented (aa divergence of 8.8% and 8.1 % compared to 22.4% and 25.6% within the protein domains encompassing cytoplasmic tail, transmembrane part and stalk regions (aa 1‐125) for genotypes XXI and VII, respectively). Nevertheless, reaction patterns of HN‐specific monoclonal antibodies inhibiting receptor binding revealed differences between vaccine type viruses and genotype XXI and VII viruses for epitopes located in the head domain. Accordingly, compared to Egyptian vaccine type isolates and the La Sota vaccine reference strain, single aa substitutions in 6 of 10 described neutralizing epitopes of HN were found. However, the same alterations in neutralization sensitive epitopes were present in old genotype XXI as well as in newly emerged genotype VII isolates. In addition, isolates were indistinguishable by polyclonal chicken sera raised against different genotypes including vaccine viruses. These findings suggest that factors other than antigenic differences within the HN protein account for facilitating the spread of genotype VII versus genotype XXI viruses in Egypt.

ACS Style

Mahmoud M. Naguib; Dirk Höper; Magdy F. Elkady; Manal A. Afifi; Ahmed Erfan; Hassanein H. Abozeid; Wafaa M. Hasan; Abdel‐Satar Arafa; Momtaz Shahein; Martin Beer; Timm C. Harder; Christian Grund. Comparison of genomic and antigenic properties of Newcastle Disease virus genotypes II, XXI and VII from Egypt do not point to antigenic drift as selection marker. Transboundary and Emerging Diseases 2021, 1 .

AMA Style

Mahmoud M. Naguib, Dirk Höper, Magdy F. Elkady, Manal A. Afifi, Ahmed Erfan, Hassanein H. Abozeid, Wafaa M. Hasan, Abdel‐Satar Arafa, Momtaz Shahein, Martin Beer, Timm C. Harder, Christian Grund. Comparison of genomic and antigenic properties of Newcastle Disease virus genotypes II, XXI and VII from Egypt do not point to antigenic drift as selection marker. Transboundary and Emerging Diseases. 2021; ():1.

Chicago/Turabian Style

Mahmoud M. Naguib; Dirk Höper; Magdy F. Elkady; Manal A. Afifi; Ahmed Erfan; Hassanein H. Abozeid; Wafaa M. Hasan; Abdel‐Satar Arafa; Momtaz Shahein; Martin Beer; Timm C. Harder; Christian Grund. 2021. "Comparison of genomic and antigenic properties of Newcastle Disease virus genotypes II, XXI and VII from Egypt do not point to antigenic drift as selection marker." Transboundary and Emerging Diseases , no. : 1.

Journal article
Published: 26 April 2021 in Virology Journal
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Background Newcastle disease is a devastating disease in poultry caused by virulent Newcastle disease virus (NDV), a paramyxovirus endemic in many regions of the world despite intensive vaccination. Phylogenetic analyses reveal ongoing evolution of the predominant circulating genotype 2.VII, and the relevance of potential antigenic drift is under discussion. To investigate variation within neutralization-sensitive epitopes within the protein responsible for receptor binding, i.e. the Hemagglutinin-Neuraminidase (HN) spike protein, we were interested in establishing genotype-specific monoclonal antibodies (MAbs). Methods An HN-enriched fraction of a gradient-purified NDV genotype 2.VII was prepared and successfully employed to induce antibodies in BalbC mice that recognize conformationally intact sites reactive by haemagglutination inhibition (HI). For subsequent screening of mouse hybridoma cultures, an NDV-ELISA was established that utilizes Concanavalin A (ConA-ELISA) coupled glycoproteins proven to present conformation-dependent epitopes. Results Six out of nine selected MAbs were able to block receptor binding as demonstrated by HI activity. One MAb recognized an epitope only present in the homologue virus, while four other MAbs showed weak reactivity to selected other genotypes. On the other hand, one broadly cross-reacting MAb reacted with all genotypes tested and resembled the reactivity profile of genotype-specific polyclonal antibody preparations that point to minor antigenic differences between tested NDV genotpyes. Conclusions These results point to the concurrent presence of variable and conserved epitopes within the HN molecule of NDV. The described protocol should help to generate MAbs against a variety of NDV strains and to enable in depth analysis of the antigenic profiles of different genotypes.

ACS Style

Ibrahim Moharam; Olayinka Asala; Sven Reiche; Hafez Hafez; Martin Beer; Timm Harder; Christian Grund. Monoclonal antibodies specific for the hemagglutinin-neuraminidase protein define neutralizing epitopes specific for Newcastle disease virus genotype 2.VII from Egypt. Virology Journal 2021, 18, 1 -13.

AMA Style

Ibrahim Moharam, Olayinka Asala, Sven Reiche, Hafez Hafez, Martin Beer, Timm Harder, Christian Grund. Monoclonal antibodies specific for the hemagglutinin-neuraminidase protein define neutralizing epitopes specific for Newcastle disease virus genotype 2.VII from Egypt. Virology Journal. 2021; 18 (1):1-13.

Chicago/Turabian Style

Ibrahim Moharam; Olayinka Asala; Sven Reiche; Hafez Hafez; Martin Beer; Timm Harder; Christian Grund. 2021. "Monoclonal antibodies specific for the hemagglutinin-neuraminidase protein define neutralizing epitopes specific for Newcastle disease virus genotype 2.VII from Egypt." Virology Journal 18, no. 1: 1-13.

Research article
Published: 23 April 2021 in PLOS Pathogens
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Repeated outbreaks due to H3N1 low pathogenicity avian influenza viruses (LPAIV) in Belgium were associated with unusually high mortality in chicken in 2019. Those events caused considerable economic losses and prompted restriction measures normally implemented for eradicating high pathogenicity avian influenza viruses (HPAIV). Initial pathology investigations and infection studies suggested this virus to be able to replicate systemically, being very atypical for H3 LPAIV. Here, we investigate the pathogenesis of this H3N1 virus and propose a mechanism explaining its unusual systemic replication capability. By intravenous and intracerebral inoculation in chicken, we demonstrate systemic spread of this virus, extending to the central nervous system. Endoproteolytic viral hemagglutinin (HA) protein activation by either tissue-restricted serine peptidases or ubiquitous subtilisin-like proteases is the functional hallmark distinguishing (H5 or H7) LPAIV from HPAIV. However, luciferase reporter assays show that HA cleavage in case of the H3N1 strain in contrast to the HPAIV is not processed by intracellular proteases. Yet the H3N1 virus replicates efficiently in cell culture without trypsin, unlike LPAIVs. Moreover, this trypsin-independent virus replication is inhibited by 6-aminohexanoic acid, a plasmin inhibitor. Correspondingly, in silico analysis indicates that plasminogen is recruitable by the viral neuraminidase for proteolytic activation due to the loss of a strongly conserved N-glycosylation site at position 130. This mutation was shown responsible for plasminogen recruitment and neurovirulence of the mouse brain-passaged laboratory strain A/WSN/33 (H1N1). In conclusion, our findings provide good evidence in natural chicken strains for N1 neuraminidase-operated recruitment of plasminogen, enabling systemic replication leading to an unusual high pathogenicity phenotype. Such a gain of function in naturally occurring AIVs representing an established human influenza HA-subtype raises concerns over potential zoonotic threats.

ACS Style

Jacob Schön; ANGELE Breithaupt; Dirk Höper; Jacqueline King; Anne Pohlmann; Rokshana Parvin; Klaus-Peter Behr; Bernd-Andreas Schwarz; Martin Beer; Jürgen Stech; Timm Harder; Christian Grund. Neuraminidase-associated plasminogen recruitment enables systemic spread of natural avian Influenza viruses H3N1. PLOS Pathogens 2021, 17, e1009490 .

AMA Style

Jacob Schön, ANGELE Breithaupt, Dirk Höper, Jacqueline King, Anne Pohlmann, Rokshana Parvin, Klaus-Peter Behr, Bernd-Andreas Schwarz, Martin Beer, Jürgen Stech, Timm Harder, Christian Grund. Neuraminidase-associated plasminogen recruitment enables systemic spread of natural avian Influenza viruses H3N1. PLOS Pathogens. 2021; 17 (4):e1009490.

Chicago/Turabian Style

Jacob Schön; ANGELE Breithaupt; Dirk Höper; Jacqueline King; Anne Pohlmann; Rokshana Parvin; Klaus-Peter Behr; Bernd-Andreas Schwarz; Martin Beer; Jürgen Stech; Timm Harder; Christian Grund. 2021. "Neuraminidase-associated plasminogen recruitment enables systemic spread of natural avian Influenza viruses H3N1." PLOS Pathogens 17, no. 4: e1009490.

Journal article
Published: 09 April 2021 in Vaccines
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Vaccination against Newcastle disease (ND), a devastating viral disease of chickens, is often hampered by thermal inactivation of the live vaccines, in particular in tropical and hot climate conditions. In the past, “thermostable” vaccine strains (I-2) were proposed to overcome this problem but previous comparative studies did not include formulation-specific factors of commercial vaccines. In the current study, we aimed to verify the superior thermal stability of commercially formulated I-2 strains by comparing six commercially available ND vaccines. Subjected to 37 °C as lyophilized preparations, two vaccines containing I-2 strains were more sensitive to inactivation than a third I-2 vaccine or compared to three other vaccines based on different ND strains. However, reconstitution strains proved to have a comparable tenacity. Interestingly, all vaccines still retained a sufficient virus dose for protection (106 EID50) after 1 day at 37 °C. These results suggest that there are specific factors that influence thermal stability beyond the strain-specific characteristics. Exposing ND vaccines to elevated temperatures of 51 and 61 °C demonstrated that inactivation of all dissolved vaccines including I-2 vaccine strains occurred within 2 to 4 h. The results revealed important differences among the vaccines and emphasize the importance of the quality of a certain vaccine preparation rather than the strain it contains. These data highlight that regardless of the ND strain used for vaccine preparation, the appropriate cold chain is mandatory for keeping live ND vaccines efficiency in hot climates.

ACS Style

Nabila Osman; Danny Goovaerts; Serageldeen Sultan; Jeremy Salt; Christian Grund. Vaccine Quality Is a Key Factor to Determine Thermal Stability of Commercial Newcastle Disease (ND)Vaccines. Vaccines 2021, 9, 363 .

AMA Style

Nabila Osman, Danny Goovaerts, Serageldeen Sultan, Jeremy Salt, Christian Grund. Vaccine Quality Is a Key Factor to Determine Thermal Stability of Commercial Newcastle Disease (ND)Vaccines. Vaccines. 2021; 9 (4):363.

Chicago/Turabian Style

Nabila Osman; Danny Goovaerts; Serageldeen Sultan; Jeremy Salt; Christian Grund. 2021. "Vaccine Quality Is a Key Factor to Determine Thermal Stability of Commercial Newcastle Disease (ND)Vaccines." Vaccines 9, no. 4: 363.

Preprint content
Published: 14 October 2020
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Background:Newcastle disease is a devastating disease in poultry caused by Newcastle disease virus (NDV), a paramyxovirus endemic in many regions of the world despite intensive vaccination. Phylogenetic analysis reveal ongoing evolution of the predominant circulating genotype 2.VII, and the relevance of potential antigenic drift is under discussion. To investigate variation within neutralization-sensitive epitopes within the protein responsible for receptor binding, i.e. the Heamagglutinin-Neuraminidase (HN) spike protein, we were interested to established genotype-specific monoclonal antibodies (MAbs). Methods:An HN-enriched fraction of a gradient-purified NDV genotype 2.VII was prepared and successfully employed to induced antibodies in BalbC mice that recognize conformationally intact sites reactive by haemagglutination inhibition (HI). For subsequent screening of mouse hybridoma cultures, an NDV-ELISA was established that utilize Concanavalin A (ConA-ELISA) coupled Glycoproteins that was proven to present conformation-dependent epitopes.Results:Six out of nine selected MAbs were able to block receptor binding as demonstrated by HI-activity. One MAb recognized an epitope only present in the homologue virus while four other MAbs showed weak reactivity to selected other genotypes. On the other hand, one broadly cross-reacting MAb reacted with all genotypes tested and resembled the reactivity profile of genotype specific polyclonal antibody preparations that point to minor antigenic differences between tested NDV genotpyes.Conclusions:These results point to the concurrent presence of variable and conserved epitopes within the HN-molecule of NDV. The described protocol should help to generate MAbs to a variety of NDV strains and enable in depth analysis of the antigenic profiles of different genotypes.

ACS Style

Ibrahim Moharam; Olayinka Asala; Sven Reiche; Timm Harder; Hafez Hafez; Martin Beer; Christian Grund. Monoclonal Antibodies Specific for the Hemagglutinin-Neuraminidase Protein Define Neutralizing Epitopes Specific for Newcastle Disease Virus Genotype 2.VII from Egypt. 2020, 1 .

AMA Style

Ibrahim Moharam, Olayinka Asala, Sven Reiche, Timm Harder, Hafez Hafez, Martin Beer, Christian Grund. Monoclonal Antibodies Specific for the Hemagglutinin-Neuraminidase Protein Define Neutralizing Epitopes Specific for Newcastle Disease Virus Genotype 2.VII from Egypt. . 2020; ():1.

Chicago/Turabian Style

Ibrahim Moharam; Olayinka Asala; Sven Reiche; Timm Harder; Hafez Hafez; Martin Beer; Christian Grund. 2020. "Monoclonal Antibodies Specific for the Hemagglutinin-Neuraminidase Protein Define Neutralizing Epitopes Specific for Newcastle Disease Virus Genotype 2.VII from Egypt." , no. : 1.

Journal article
Published: 01 July 2020 in Infection, Genetics and Evolution
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Infectious bronchitis virus (IBV), a gamma-coronavirus, causes infectious bronchitis (IB), a major respiratory disease of chicken. Its high mutation rate in conjunction with recombination of the RNA genome constantly creates IBV variants that are difficult to control by currently available vaccines. In this study, we addressed the question whether small-scale holdings might harbor IBV variants that serve as a reservoir for newly emerging variants. Egyptian IBV isolate EGY/NR725/2016 (NR725/16) from a small-scale broiler farm was assigned to genotype I, clade 23 (S1:GI-23), based on partial S1 gene sequences and corroborated by full genome sequencing. Analysis of the S1 gene established three subclades for historical IBV strains (S1:GI-23.1, S1:GI-23.2.1 and S1:GI-23.2.2) and confirmed NR725/16 as being part of a separate fourth subclade (S1:GI-23.3). Samples from the years 2018 and 2019 revealed that the new subclade prevails in Egypt, carrying fixed mutations within the hypervariable regions (HVR) 1-3 of the S1 protein that affect two neutralization sensitive epitopes at sites 294F, 297S and 306Y (48.2) and 329R (62.1). In addition, recombination was recognized in isolate NR 725/16, with intra-subtype mixing for the entire genes 3ab and E and inter-subtype mixing for the entire gene 6b with a close match to QX like viruses of genotype GI-19. Further analysis of gene 3ab detected the homologous gene pool to NR725/16 in samples from 2013 (3ab:C) and closely related 3ab genotypes in IBV Egyptian isolates from 2016, 2018 and 2019. These data prove a flourishing exchange between poultry holdings with a common gene pool. The continued circulation of viruses harboring genes S1:GI-23.3 and 3ab:C indicates an evolutionary advantage of this combination possibly by combining antigenic escape with modulated pathogenicity to facilitate IBV spread in the vaccinated poultry population in Egypt.

ACS Style

Ibrahim Moharam; Hesham Sultan; K. Hassan; Mahmoud Ibrahim; Salama Shany; Awad A. Shehata; Mohammed AboElkhair; Florian Pfaff; Dirk Höper; Magdy EL Kady; Martin Beer; Timm Harder; Hafez Hafez; Christian Grund. Emerging infectious bronchitis virus (IBV) in Egypt: Evidence for an evolutionary advantage of a new S1 variant with a unique gene 3ab constellation. Infection, Genetics and Evolution 2020, 85, 104433 -104433.

AMA Style

Ibrahim Moharam, Hesham Sultan, K. Hassan, Mahmoud Ibrahim, Salama Shany, Awad A. Shehata, Mohammed AboElkhair, Florian Pfaff, Dirk Höper, Magdy EL Kady, Martin Beer, Timm Harder, Hafez Hafez, Christian Grund. Emerging infectious bronchitis virus (IBV) in Egypt: Evidence for an evolutionary advantage of a new S1 variant with a unique gene 3ab constellation. Infection, Genetics and Evolution. 2020; 85 ():104433-104433.

Chicago/Turabian Style

Ibrahim Moharam; Hesham Sultan; K. Hassan; Mahmoud Ibrahim; Salama Shany; Awad A. Shehata; Mohammed AboElkhair; Florian Pfaff; Dirk Höper; Magdy EL Kady; Martin Beer; Timm Harder; Hafez Hafez; Christian Grund. 2020. "Emerging infectious bronchitis virus (IBV) in Egypt: Evidence for an evolutionary advantage of a new S1 variant with a unique gene 3ab constellation." Infection, Genetics and Evolution 85, no. : 104433-104433.

Journal article
Published: 28 April 2020 in Vaccines
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Peste des petits ruminants virus (PPRV, species: small ruminant morbillivirus) is the causative agent of the eponymous notifiable disease, the peste des petits ruminants (PPR) in wild and domestic sheep and goats. Mortality rates vary between 50% and 100%, causing significant losses of estimated 1.5 to 2 billion US Dollars per year. Live-attenuated PPRV vaccine strains are used in the field for disease prevention, but the application of a more thermostable vaccine enabling differentiation between infected and vaccinated animals (DIVA) would be highly desirable to achieve the goal of global disease eradication. We generated a recombinant Newcastle disease virus (rNDV) based on the live-attenuated NDV Clone 30 that expresses the surface protein hemagglutinin (H) of PPRV strain Kurdistan/11 (rNDV_HKur). In vitro analyses confirmed transgene expression as well as virus replication in avian, caprine, and ovine cells. Two consecutive subcutaneous vaccinations of German domestic goats with rNDV_HKur prevented clinical signs and hematogenic dissemination after an intranasal challenge with virulent PPRV Kurdistan/11. Virus shedding by different routes was reduced to a similar extent as after vaccination with the live-attenuated PPRV strain Nigeria 75/1. Goats that were either not vaccinated or inoculated with parental rNDV were used as controls. In summary, we demonstrate in a proof-of-concept study that an NDV vectored vaccine can protect against PPR. Furthermore, it provides DIVA-applicability and a high thermal tolerance.

ACS Style

Magdalena Murr; Bernd Hoffmann; Christian Grund; Angela Römer-Oberdörfer; Thomas C. Mettenleiter. A Novel Recombinant Newcastle Disease Virus Vectored DIVA Vaccine against Peste des Petits Ruminants in Goats. Vaccines 2020, 8, 205 .

AMA Style

Magdalena Murr, Bernd Hoffmann, Christian Grund, Angela Römer-Oberdörfer, Thomas C. Mettenleiter. A Novel Recombinant Newcastle Disease Virus Vectored DIVA Vaccine against Peste des Petits Ruminants in Goats. Vaccines. 2020; 8 (2):205.

Chicago/Turabian Style

Magdalena Murr; Bernd Hoffmann; Christian Grund; Angela Römer-Oberdörfer; Thomas C. Mettenleiter. 2020. "A Novel Recombinant Newcastle Disease Virus Vectored DIVA Vaccine against Peste des Petits Ruminants in Goats." Vaccines 8, no. 2: 205.

Abstract
Published: 01 January 2020 in Proceedings
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Highly pathogenic avian influenza virus (HPAIV) belongs to the Orthomyxoviridae family and causes a systemic and highly lethal disease in poultry. Vaccination with recombinant Newcastle disease vector viruses (NDV) expressing the hemagglutinin (HA) of HPAIV H5N1 induces high antibody titers in chickens free of specific pathogens, conveying protection against a lethal infection with HPAIV H5N1. Protection of chickens possessing maternally derived NDV immunity was achieved after the replacement of the surface proteins of NDV, the fusion protein (F), and the hemagglutinin-neuraminidase protein (HN) against those of avian paramyxovirus serotype 8. However, maternal AIV antibodies (αAIV-MDA+) still interfere with vaccine virus replication, resulting in inefficient protection. For our study, recombinant rNDVsolH5_H5 was generated. The insertion of a transgene encoding a truncated soluble HA between the NDV phosphoprotein and matrix protein genes—in addition to the gene encoding a membrane-bound HA inserted between the NDV, F and HN of the lentogenic NDV Clone 30 —was expected to increase the total amount of HA expressed by the recombinant virus. Western blot and mass spectrometry analyses confirmed the increase in HA expression compared to the parental rNDVH5 expressing only the full-length HA. The protective efficacy of the newly generated recombinant NDV was tested in an animal experiment. αAIV-MDA+ chickens were vaccinated either 7, 14, or 21 days after hatching. A homologous challenge infection was carried out three weeks later. Although the youngest chickens showed the highest titer of αAIV-MDA, there were no AIV antibodies detectable 21 days after vaccination. However, 40% of vaccinated chickens were protected, while 85% and 100% protection was observed in the middle-aged and oldest chickens, which had low and no detectable levels of αAIV-MDA, and moderate and high AIV antibody levels after vaccination, respectively. Challenge infection of non-vaccinated chickens resulted in high mortality.

ACS Style

Magdalena Murr; Olayinka Asala; Axel Karger; Christian Grund; Thomas C. Mettenleiter; Angela Römer-Oberdörfer. Protection of Chickens with Maternal Avian Influenza Virus (AIV) Immunity after Vaccination with a Recombinant AIV-Newcastle Disease Vector. Proceedings 2020, 50, 83 .

AMA Style

Magdalena Murr, Olayinka Asala, Axel Karger, Christian Grund, Thomas C. Mettenleiter, Angela Römer-Oberdörfer. Protection of Chickens with Maternal Avian Influenza Virus (AIV) Immunity after Vaccination with a Recombinant AIV-Newcastle Disease Vector. Proceedings. 2020; 50 (1):83.

Chicago/Turabian Style

Magdalena Murr; Olayinka Asala; Axel Karger; Christian Grund; Thomas C. Mettenleiter; Angela Römer-Oberdörfer. 2020. "Protection of Chickens with Maternal Avian Influenza Virus (AIV) Immunity after Vaccination with a Recombinant AIV-Newcastle Disease Vector." Proceedings 50, no. 1: 83.

Articles
Published: 25 July 2019 in Avian Pathology
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Highly contagious Newcastle disease (ND) is associated with devastating outbreaks with highly variable clinical signs among gallinaceous birds. In this study we aimed to verify clinical ND suspicions in poultry holdings in Egypt suffering from respiratory distress and elevated mortality, comparing two groups of ND-vaccinated poultry holdings in three governorates. Besides testing for Newcastle disease virus (NDV), samples were screened for infectious bronchits virus (IBV) and avian influenza virus (AIV) by RT-qPCR as well as by non-directed cell-culture approach on LMH-cells. Virulent NDV was confirmed only in group A (n = 16) comprising small-scale holdings. Phylogenetic analysis of the fusion protein gene of 11 NDV-positive samples obtained from this group assigned all viruses to genotype 2.VIIb and point to four different virus populations that were circulating at the same time in one governorate, indicating independent epidemiological events. In group B, comprising large commercial broiler farms (n = 10), virulent NDV was not present, although, in six farms NDV vaccine type virus (genotype 2.II) was detected. Besides, in both groups, co-infections by IBV (n = 8), AIV H9 (n = 3) and/or avian reovirus (ARV) (n = 5) and avian astrovirus (AastVs) (n = 1) could be identified. Taken together, the study confirmed clinical ND suspicion in small scale holdings, pointing to inefficient vaccination practice in this group A. However, it also highlighted that even in an endemic situation like ND in Egypt, in cases of suspected ND vaccine failure, clinical ND suspicion has to be verified by pathotype-specific diagnostic tests.

ACS Style

Ibrahim Moharam; Alaa Abd El Razik; Hesham Sultan; Mohammed Ghezlan; Clement Meseko; Kati Franzke; Timm Harder; Martin Beer; Christian Grund. Investigation of suspected Newcastle disease (ND) outbreaks in Egypt uncovers a high virus velogenic ND virus burden in small-scale holdings and the presence of multiple pathogens. Avian Pathology 2019, 48, 406 -415.

AMA Style

Ibrahim Moharam, Alaa Abd El Razik, Hesham Sultan, Mohammed Ghezlan, Clement Meseko, Kati Franzke, Timm Harder, Martin Beer, Christian Grund. Investigation of suspected Newcastle disease (ND) outbreaks in Egypt uncovers a high virus velogenic ND virus burden in small-scale holdings and the presence of multiple pathogens. Avian Pathology. 2019; 48 (5):406-415.

Chicago/Turabian Style

Ibrahim Moharam; Alaa Abd El Razik; Hesham Sultan; Mohammed Ghezlan; Clement Meseko; Kati Franzke; Timm Harder; Martin Beer; Christian Grund. 2019. "Investigation of suspected Newcastle disease (ND) outbreaks in Egypt uncovers a high virus velogenic ND virus burden in small-scale holdings and the presence of multiple pathogens." Avian Pathology 48, no. 5: 406-415.