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Vilmos Palya

I am Doctor in Veterinary Medicine graduated in 1966 at the University of Veterinary Science, Budapest, Hungary. In 1973 I obtained a Post-graduate diploma in Microbiology and Diseases of Cattle at the same University. In 2007 I was recognized as Honorary Professor by the Faculty of Veterinary Science of St. Steve University of Agriculture, Hungary. In recognition of my contribution in the furtherance of poultry veterinary science, the World Veterinary Poultry Association at their Congress in Edinburgh, Scotland, 2017 inducted me to be member of the “Hall of Honour”. I have extensive experience at various positions related to laboratory management and animal diseases control over a 50 years career. I was working more than 30 years in the field of poultry diseases diagnostics. I have substantial experience in setting up diagnostic laboratories in Europe, Asia and Africa, and training professional staff in laboratory techniques and disease control methods. I have performed extensive research and made several publications on IBD, ND, AI, IB, fowl adenoviruses (IBH), avian reoviruses and waterfowl parvoviruses. During the last two decades I have been working primarily in the field of vaccinology to improve conventional vaccines, developing and testing new generation vaccines (recombinant HVT-IBD, HVT-ND and HVT-AI) for the control of major viral poultry diseases. During the 80’s and 90’s I was working as UN/FAO vaccine expert in several African, Middle East and Asian countries to support global and national disease control/eradication programmes (e.g., Rinderpest, CBPP, Newcastle disease).Present position: Scientific adviser, Ceva-Phylaxia Veterinary Biologicals Co., Szallas u.5., 1107-Budapest, Hungary.I have published over 150 peer reviewed articles, giving numerous presentations and preparing consultancy reports. I wrote the section on Parvovirus Infections of Waterfowl in the 13th edition of Diseases of Poultry.Membership of professional bodies: Hungarian Society of Veterinarian (Poultry Diseases Section), Hungarian Society of Microbiology, World Veterinary Poultry Association, American Association of Avian Pathologists, Society of General Microbiology, International Association of Biological Standardization.

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Papers by Vilmos Palya

Background: Actinobacillus pleuropneumoniae is a major economically significant bacterial respira... more Background: Actinobacillus pleuropneumoniae is a major economically significant bacterial respiratory pathogen of pigs, and vaccine use is considered an integral control method to prevent disease. The objective of this multi-study analysis was to evaluate the serovar independent efficacy in growing pigs of the C-vaccine (Coglapix®, Ceva, France), which comprises whole cells of A. pleuropneumoniae serovars 1 and 2 expressing ApxI, ApxII and ApxIII toxins. Efficacy was based on protection against lung lesions, since there is good correlation between the severity/extension of lung lesions and losses induced by pleuropneumonia. Vaccine efficacy was determined against challenge with the most common serovars (1, 2, 4, 5, 6, 7, 9/11 and 13) of A. pleuropneumoniae in a total of 13 studies of the same design and reproducibility was validated.Results: Protection against homologous serovars 1 and 2 significantly reduced lung lesion scores (LLS) compared to the positive controls: p = 0.00007 an...

Magyar Allatorvosok Lapja, 1990

Diseases of Poultry, 2019

Archives of Virology, 2004

Avian Diseases, 2018

SUMMARY. The most recent pandemic clade of highly pathogenic avian influenza (HPAI) H5, clade 2.3... more SUMMARY. The most recent pandemic clade of highly pathogenic avian influenza (HPAI) H5, clade 2.3.4.4, spread widely, with the involvement of wild birds, most importantly wild waterfowl, carrying the virus (even asymptomatically) from Asia to North America, Europe, and Africa. Domestic waterfowl being in regular contact with wild birds played a significant role in the H5Nx epizootics. Therefore, protection of domestic waterfowl from H5Nx avian influenza infection would likely cut the transmission chain of these viruses and greatly enhance efforts to control and prevent disease outbreak in other poultry and animal species, as well as infection of humans. The expectation for such a vaccine is not only to provide clinical protection, but also to control challenge virus transmission efficiently and ensure that the ability to differentiate infected from vaccinated animals is retained. A water-in-oil emulsion virus-like particle vaccine, containing homologous hemagglutinin antigen to the current European H5N8 field strains, has been developed to meet these requirements. The vaccine was tested in commercial Pekin and mule ducks by vaccinating them either once, at 3 wk of age, or twice (at 1 day and at 3 wk of age). Challenge was performed at 6 wk of age with a Hungarian HPAIV H5N8 isolate (2.3.4.4 Group B). Efficacy of vaccination was evaluated on the basis of clinical signs, amount of virus shedding, and transmission. Vaccination resulted in complete clinical protection and prevention of challenge virus transmission from the directly challenged vaccinated ducks to the vaccinated contact animals.

Vaccines

To investigate the immunogenic cross reactivity between goose parvovirus (GPV) and Muscovy duck p... more To investigate the immunogenic cross reactivity between goose parvovirus (GPV) and Muscovy duck parvovirus (MDPV), cross-neutralization was carried out with serum samples collected from birds after infection with one of the two waterfowl parvoviruses. The significantly higher virus neutralization titer obtained against the homologous virus than against the heterologous one suggests important differences between the GPV and MDPV antigenic make up that affects the induced protective virus-neutralizing antibody specificity. This was further confirmed by cross-protection studies carried out in waterfowl parvovirus antibody-free Muscovy ducks immunized at one day of age with whole-virus inactivated oil-emulsion vaccines containing either GPV or MDPV as a monovalent vaccine, or both viruses as a bivalent vaccine. Protection against the clinical disease (growth retardation and feathering disorders) provided by the monovalent vaccine was complete against homologous virus challenge at 2 week...

Waterfowl play a key role in the epidemiology of the H5N1 subtype of highly pathogenic avian infl... more Waterfowl play a key role in the epidemiology of the H5N1 subtype of highly pathogenic avian influenza (HPAI) virus, therefore efficient immunization of domesticated ducks and geese to maximize the impact of other control measures is of great importance. Previous studies have shown that herpesvirus of turkey (HVT) is able to replicate in certain species of waterfowl. A recombinant HVT-AI vaccine (rHVT-AI), expressing the HA gene of a clade 2.2 H5N1 HPAIV strain had been developed and proved to be efficient against different clades of H5N1 HPAIV in chickens after a single vaccination at day-old and could provide long-term immunity. In the study presented here we investigated if rHVT-AI is able to replicate in different species and cross-breeds of ducks and in geese with the aim of collecting data on the possible application of rHVT-AI vaccine in different species of waterfowl for the control of H5N1 HPAI. In the studies conducted we tested the possible differences among different wat...

Avian Pathology, 2004

Recent outbreaks of haemorrhagic nephritis enteritis in geese flocks of 3 to 10 weeks in age in H... more Recent outbreaks of haemorrhagic nephritis enteritis in geese flocks of 3 to 10 weeks in age in Hungary were investigated. Mortality varied between 4% and 67%. Affected birds generally died suddenly. Occasional clinical signs included tremors of the head and neck, subcutaneous haemorrhages and excretion of faeces containing partly digested blood. At necropsy the most frequent findings were a turgid wall and reddish mucosa of the intestines and reddish discolouration of the swollen kidneys, but oedema and haemorrhages of the subcutaneous connective tissue, hydropericardium and ascites were also seen. In subacute cases, visceral gout was frequently observed. Histological examination revealed zonal necrosis of the tubular epithelial cells with haemorrhages in the kidney. Other histological findings were serous hepatitis with fatty infiltration, necrotizing haemorrhagic enteritis and haemorrhages in the different organs including the brain. Experimental geese infected parenterally with crude liver and spleen homogenates prepared from diseased birds died after 8 to 20 days without premonitory signs, and had typical gross and histological lesions. Attempts to isolate cytopathic virus on different tissue cultures failed. The presence of polyomavirus was proven by polymerase chain reaction. Five isolates were further investigated by analysing their complete VP1 gene sequence. All tested strains were very closely related to each other on the basis of the nucleotide sequence, and they were identical at the deduced amino acid level.

Life, 2022

Avian infectious bronchitis (IB) is among the major viral respiratory and reproductive diseases o... more Avian infectious bronchitis (IB) is among the major viral respiratory and reproductive diseases of chickens caused by Avian coronavirus. In the African continent, IB was first described in countries located in the Mediterranean basin. In other parts of the continent, the epidemiological situation of IB remains unclear. In this study, the complete genome sequences of five IBV strains, originating from the sub-Saharan area were determined. Phylogenetic analysis based on the full-length S1 sequences identified three lineages (GI-14, GI-16, and GI-19) common in Africa and revealed that a strain, D2334/11/2/13/CI, isolated in Ivory Coast may represent a novel lineage within genotype GI. The maximum inter- and intragenotype sequence identities between this strain and other IBVs were 67.58% and 78.84% (nucleotide) and 64.44% and 78.6% (amino acid), respectively. The whole-genome nucleotide identity of the novel variant shared the highest values with a reference Belgian nephropathogenic str...

Magyar Allatorvosok Lapja, 2007

Magyar Allatorvosok Lapja, 2002

We determined the genomic sequence of a Ukrainian strain of fowl adenovirus B (FAdV-B). The isola... more We determined the genomic sequence of a Ukrainian strain of fowl adenovirus B (FAdV-B). The isolate (D2453/1) shared 97.2% to 98.4% nucleotide sequence identity with other viruses belonging to the species Fowl aviadenovirus B. Marked genetic divergence was seen in the hexon, fiber, and ORF19 genes, and phylogenetic analysis suggested that recombination events had occurred in these regions. Our analysis revealed mosaicism in the recombination patterns, a finding that has also been described in the genomes of strains of FAdV-D and FAdV-E. The shared recombination breakpoints, affecting the same genomic regions in viruses belonging to different species, suggest that similar selection mechanisms are acting on the key neutralization antigens and epitopes in viruses of different FAdV species. Supplementary Information The online version contains supplementary material available at 10.1007/s00705-021-04972-9.

Emerging Infectious Diseases, 2019

Steps Forwards in Diagnosing and Controlling Influenza, 2016

Avian diseases, 2016

A highly pathogenic avian influenza (HPAI) H5N8 (clade 2.3.4.4) virus, circulating in Asia (South... more A highly pathogenic avian influenza (HPAI) H5N8 (clade 2.3.4.4) virus, circulating in Asia (South Korea, Japan, and southern China) since the beginning of 2014, reached the European continent in November 2014. Germany, the Netherlands, the United Kingdom, Italy, and Hungary confirmed H5N8 infection of poultry farms of different species and of several wild bird species. Unlike the Asian highly pathogenic (HP) H5N1, this HP H5N8 also went transatlantic and reached the American West Coast by the end of 2014, affecting wild birds as well as backyard and commercial poultry. This strain induces high mortality and morbidity in Galliformes, whereas wild birds seem only moderately affected. A recombinant turkey herpesvirus (rHVT) vector vaccine expressing the H5 gene of a clade 2.2 H5N1 strain (rHVT-H5) previously demonstrated a highly efficient clinical protection and reduced viral excretion against challenge with Asian HP H5N1 strains of various clades (2.2, 2.2.1, 2.2.1.1, 2.1.3, 2.1.3.2,...