identification of infectious bronchitis virus by interference with the b-1 isolant of newcastle disease virus. waxing and waning of interference.the massachusetts and the connecticut types of infectious bronchitis virus (ibv) were identified by interference in embryonating chicken eggs (ece) with the production of hemagglutinin by the b-1 isolant of newcastle disease virus (ndv). this interference test appears to be specific because the above interference was eliminated by adding type-specific anti-ibv serum to the ibv-ndv system; however, interference was not detectable when fowlpox virus (fpv) and infectious laryngotracheitis virus (lt ...1975168852
recombinant fowlpox viruses expressing the glycoprotein b homolog and the pp38 gene of marek's disease virus.two marek's disease virus (mdv) genes, one homologous to the glycoprotein b gene of herpes simplex virus and encoding the b antigen complex and the other encoding a 38-kda phosphorylated protein (pp38), were inserted into the fowlpox virus (fpv) genome under the control of poxvirus promoters. randomly selected nonessential regions of fpv were used for insertion, and the vaccinia virus 7.5 kda polypeptide gene promoter or a poxvirus synthetic promoter was used for expression of mdv genes. gene ex ...19921310754
recent advances in avian virology.selected, recent research on the following avian diseases, and their causative viruses, has been reviewed: chicken anaemia, infectious bursal disease, turkey rhinotracheitis, avian nephritis, fowlpox, influenza, infectious bronchitis and turkey enteritis.19921319788
oral fowlpox vaccination in chickens.chickens were given various fowlpox vaccines on food pellets--a commercial vaccine (strain m), and the same strain after a single passage on chorio-allantoic membrane or in chicken embryo fibroblasts. all three oral vaccines induced antibodies at levels similar to those induced by commercial strain m administered to the wingweb. the oral vaccine derived from chorio-allantoic membrane gave protection similar to that obtained with vaccine administered by the wingweb, but this required a thousandfo ...19921325725
structural analysis of unstable intermediate and stable forms of recombinant fowlpox virus.the stability and structure of the products of recombination in a fowlpox virus (fpv) system using the thymidine kinase (tk) gene as the insertion site were examined. a 4.6 kb chimeric dna fragment from the puv1 expression vector, containing the bacterial lacz gene and the vaccinia virus p7.5 promoter, was ligated into the xbai site of the fpv tk gene. the resulting vector, pftklaczb, was transfected into chicken embryo fibroblast cultures infected with fpv at an m.o.i. of 0.1. recombinants were ...19911658207
a recombinant fowlpox virus that expresses the vp2 antigen of infectious bursal disease virus induces protection against mortality caused by the virus.the coding sequences of vp2 from a virulent strain, 52/70, of infectious bursal disease virus (ibdv) were excised from a cdna clone and inserted into a fowlpox plasmid insertion vector. the resulting plasmid, pibd 1, was used to construct a recombinant fowlpox virus, fpibd 1, which expressed vp 2 as a beta-galactosidase fusion protein. chickens vaccinated with fpibd 1 at 1 and 14 days of age, were challenged at 28 days with either ibdv strain 52/70 or the highly virulent strain cs 89. these chic ...19911659797
expression of avian influenza virus hemagglutinin by recombinant fowlpox virus.a vaccine strain of fowlpox virus (fpv) was genetically engineered to produce avian influenza virus hemagglutinin (ha). this was accomplished by inserting a cdna copy of the avian influenza virus ha gene, which was regulated by a vaccinia virus promoter, into the fpv thymidine kinase (tk) gene. two types of recombinant viruses, differing only in the orientation of the ha gene relative to an adjacent foreign gene (lacz), were created. following preliminary identification of fpv recombinants based ...19911851414
the primary structure of the thymidine kinase gene of fish lymphocystis disease virus.the dna nucleotide sequence of the thymidine kinase (tk) gene of fish lymphocystis disease virus (fldv) which has been localized between the coordinates 0.678 to 0.688 of the viral genome was determined. the analysis of the dna nucleotide sequence located between the recognition sites of hindiii (0.669 map unit; nucleotide position 1) and acci (nucleotide position 2032) revealed the presence of an open reading frame of 954 bp on the lower strand of this region between nucleotide positions 1868 ( ...19912024501
quaternary structure of vaccinia virus thymidine kinase.thymidine kinase enzymes isolated from a variety of sources are generally considered to have a native molecular weight of 80-90 kda composed of two 40-45 kda subunits. although these parameters may accurately describe the atypical deoxypyrimidine kinases expressed by members of the herpesviridae, the nucleotide sequences of thymidine kinase genes isolated from human, mouse, chicken and variety of poxviruses (vaccinia virus, monkeypox virus, variola virus, fowlpox virus and capripoxvirus) predict ...19902114104
insertion of the fusion gene from newcastle disease virus into a non-essential region in the terminal repeats of fowlpox virus and demonstration of protective immunity induced by the this paper we report on the identification of non-essential genes in the terminal repeats of the avipox-virus fowlpox virus and the use of these as insertion sites in a vector system. foreign genes inserted into these sites are shown to be present in two copies in the resultant recombinant virus. to test the potential use of this vector as a live vaccine the fusion gene of newcastle disease virus has been inserted into a vaccine strain of fowlpox virus and inoculated into chickens. the experi ...19902155997
comparative analysis of vaccinia virus promoter activity in fowlpox and vaccinia virus recombinants.a quantitative and qualitative comparison of vaccinia virus (vv) promoter activity in fowlpox virus (fpv) and vv recombinants was performed. the vv pl11 late promoter was used to express beta-galactosidase from the e. coli lacz gene in fpv (fpv-lacz) and vv (vv-lacz) recombinants. time courses of fpv-lacz beta-galactosidase expression in chicken embryo skin (ces) cells demonstrated temporal regulation of the pl11 promoter with maximum enzyme activity nine- and four-fold lower than those obtained ...19902161593
a fowlpox virus vaccine vector with insertion sites in the terminal repeats: demonstration of its efficacy using the fusion gene of newcastle disease this paper we report the development and testing of a fowlpox virus vector system. insertion sites in non-essential regions within the terminal inverted repeats of the virus have been characterised. foreign genes inserted into these sites are shown to be present in two copies in the resultant recombinant virus. to test the potential use of this vector as a live vaccine the fusion gene of newcastle disease virus (ndv) has been inserted into a vaccine strain of fowlpox virus, and inoculated int ...19902169678
protection of chickens with a recombinant fowlpox virus expressing the newcastle disease virus hemagglutinin-neuraminidase gene.a recombinant fowlpox virus expressing the hemagglutinin-neuraminidase (hn) protein of newcastle disease virus (ndv) strain texas was generated. immunoprecipitation with chicken anti-ndv serum confirmed authentic expression of the hn protein. protection of chickens from infection with ndv was observed when birds were immunized with the recombinant hn fowlpox virus by the intramuscular route after one or two inoculations. vaccination by the ocular route with a mixture of fowlpox recombinants expr ...19902173266
vaccination of 1-day-old chicks with fowlpox virus by the aerosol, drinking water, or cutaneous routes.administration of 10(4) mean cell-culture infectious dose (ccid50) per ml of a plaque-purified derivative of a commercial fowlpox virus (fpv) vaccine to 1-day-old chicks by aerosol or drinking water gave inconsistent serological responses and little evidence of protective immunity. in contrast, cutaneous vaccination with the same preparation protected against challenge with virulent fpv at 4 weeks of age. administration of the vaccine at a concentration of 10(6) ccid50 per ml by the drinking-wat ...19902173536
recombinant fowlpox viruses inducing protective immunity against newcastle disease and fowlpox viruses.the haemagglutinin-neuraminidase gene of newcastle disease virus was inserted into a non-essential region of the fowlpox virus genome and expressed under control of the vaccinia virus 7.5 kda polypeptide gene promoter. immunization with the recombinant fowlpox virus elicited protective immunity in chickens against both virulent newcastle disease and fowlpox virus infection.19902174598
analysis of the fowlpox virus genome region corresponding to the vaccinia virus d6 to a1 region: location of, and variation in, non-essential genes in poxviruses.the dna sequence of the fowlpox virus genome corresponding to the vaccinia virus d6 to a1 region has been determined. translation of this sequence reveals fowlpoxvirus gene homologues corresponding to the d6, d7, d9, d10, d11, d12, d13 and a1 genes of vaccinia virus. in contrast, no gene homologue for the non-essential vaccinia virus d8 gene was present in fowlpox virus. instead, a gene transcribed from the opposite strand to the vaccinia virus d8 gene showing no homology to any previously seque ...19902177083
a 39,000 mr immunodominant protein of fowlpox virus contains multiple copies of a 12 amino acid repeat sequence.the nucleotide sequence of an unusual fowlpox virus gene which maps immediately upstream from the fowlpox virus 4b gene has been determined. the 34,000 mr protein predicted to be encoded by the gene contains 11 copies of a 12 amino acid serine-rich repeat sequence. the seven amino-terminal copies of the repeat sequence are perfectly conserved but variation exists in the four carboxy-terminal copies. three peptides were synthesized which contained either one copy of the repeat sequence, two copie ...19902177084
sequence and evolutionary relationships of african swine fever virus thymidine kinase.the thymidine kinase gene of african swine fever virus was mapped in a 1.4-kb ecori-psti fragment located in the left half of the eco ri k fragment of african swine fever virus dna by using degenerate oligonucleotide probes derived from regions of the thymidine kinase sequence conserved in several poxviruses, man, mouse, and chicken. the nucleotide sequence of this region revealed an open reading frame of 196 codons, whose translated amino acid sequence showed significant similarity to the thymi ...19902389555
fowlpox virus polypeptides: sequential appearance and virion associated polypeptides.the polypeptides associated with fowlpox virus (fpv) infection of chicken embryo skin (ces) cells were examined by metabolic labelling with [35s]-methionine and sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page). polypeptide synthesis was followed over the first 48 hours post infection, as this was shown to be the period of viable virus production in ces cells. in contrast to infection with vaccinia virus (vv), which leads to a rapid total inhibition of host polypeptide synthes ...19872821960
sequence analysis of an 11.2 kilobase, near-terminal, bamhi fragment of fowlpox virus.the nucleotide sequence of an 11.2 kilobase fragment of the fowlpox virus genome is presented. the fragment comes from near one end of the genome and contains part of the terminal inverted repeat. twenty open reading frames (orfs) are predicted from the sequence and are classified into 13 major and seven minor orfs. the 100 base pairs immediately upstream of each orf are up to 83% at-rich, with some motifs similar to those seen in vaccinia virus early gene promoters. the tttttnt element which ha ...19882836548
construction of recombinant fowlpox viruses as vectors for poultry vaccines.plasmid vectors have been constructed which allow the construction of infectious fowlpox virus (fpv) recombinants expressing foreign genes. the foreign genes were inserted within the thymidine kinase (tk) gene of fpv contained in these vectors. to facilitate the selection of recombinants the escherichia coli xanthine guanine phosphoribosyl transferase (ecogpt) gene was developed as a dominant selectable marker. this marker operates in a wide variety of cell types and obviates the need for tk- ce ...19882842977
cell-culture virus-neutralization test and enzyme-linked immunosorbent assay for evaluation of immunity in chickens against fowlpox.two serological tests--the virus-neutralization (vn) test in chicken embryo fibroblasts (cef) using a cell-culture-adapted virus, and the enzyme-linked immunosorbent assay (elisa)--were used for evaluating the immune response in chickens against fowlpox virus. the vn test was conducted in 96-well tissue-culture plates using a fowlpox virus that was adapted to induce cytopathic effects (cpe) in cef in 48 hr. the elisa was carried out with an antigen prepared by precipitation of a cell-culture-pro ...19853000336
a recombinant fowlpox virus expressing the hemagglutinin-neuraminidase gene of newcastle disease virus (ndv) protects chickens against challenge by ndv.the hemagglutinin-neuraminidase (hn) gene from the beaudette c strain of newcastle disease virus (ndv) has been expressed in a recombinant fowlpox virus vector. the hn gene, under the control of the vaccinia p7.5 promoter, was inserted into a nonessential gene in the terminal inverted repeats of fowlpox virus. expression was demonstrated in tissue culture, a protein of the correct size for fully glycosylated hn protein being recognized by an hn-specific monoclonal antibody on western blots. when ...19902167557
fowlpox virus thymidine kinase: nucleotide sequence and relationships to other thymidine kinases.the thymidine kinase (tk) gene of fowlpox virus (fpv) is located in a 2.2-kb hindiii-clai fragment derived from a 5.5-kb ecor1 fragment of the fpv genome. the tk gene was mapped to the region of a 700-bp xbai fragment contained within this hindiii-clai fragment. nucleotide sequence analysis of this region revealed an open reading frame of 183 codons. identification of this region as the fpv tk gene was confirmed by its homology with the vaccinia virus tk at both the nucleotide and amino acid lev ...19873027984
newcastle disease virus fusion protein expressed in a fowlpox virus recombinant confers protection in chickens.a cdna copy of the rna encoding the fusion (f) protein of newcastle disease virus (ndv) strain texas, a velogenic strain of ndv, was obtained and the sequence was determined. the 1,792-base-pair sequence encodes a protein of 553 amino acids which has essential features previously established for the f protein of virulent ndv strains. these include the presence of three strongly hydrophobic regions and pairs of dibasic amino acids in the pentapeptide arg-arg-gln-arg-arg preceding the putative cle ...19902157037
antibody response to newcastle disease virus (ndv) of recombinant fowlpox virus (fpv) expressing a hemagglutinin-neuraminidase of ndv into chickens in the presence of antibody to ndv or fpv.antibody response of recombinant fowlpox virus (fpv) was studied in chickens inoculated with the virus in the presence or absence of antibodies against newcastle disease virus (ndv) or fpv. in the case of ndv, high hemagglutination-inhibition titers to ndv were obtained when the antibody was present. no immune response to ndv was observed in the chickens previously vaccinated with fpv.19911664717
fowlpox virus: pathogenicity and vaccination of day-old chickens via the aerosol chickens were given a single fowlpox virus vaccination (strain hp201) either via the aerosol or wing-web route. both methods induced protective immunity against a wing-web or intravenous challenge with virulent fowlpox virus at 47 days old, although high titred virus preparations were required for successful aerosol vaccination. however, no clinical signs of infection were observed as a result of aerosol vaccination even if invasive strains of escherichia coli were administered simultane ...19911652784
[aerosol vaccination of poultry against pox]. 19806249019
efficacy of nucleoprotein and haemagglutinin antigens expressed in fowlpox virus as vaccine for influenza in chickens.fowlpox virus (fpv) recombinants expressing influenza virus h5 haemagglutinin (ha), nucleoprotein (np) or co-expressing both of these antigens were tested for vaccine efficacy in chickens. immunization with the recombinant fpv-ha was highly efficacious but provided no cross protection between subtypes. bursectomy established that immunity against the h5 subtype was antibody-mediated despite the presence of very low levels of antibody in the vaccinated birds. immunization with the recombinant fpv ...19911651609
effect of route of administration on the efficacy of a recombinant fowlpox virus against h5n2 avian influenza.a recombinant fowlpox vaccine virus containing the h5 hemagglutinin gene of avian influenza virus was administered to susceptible chickens via wing-web puncture, eye drop, instillation into the nares, and drinking water. even though there was a negligible hemagglutination-inhibition (hi) serologic response, all 10 chickens vaccinated by wing-web puncture remained without obvious signs of disease and survived challenge with a highly pathogenic strain of h5n2 avian influenza virus. all unvaccinate ...19921336657
effects of fowlpox virus infection on lipid metabolism in cultured chicken embryo cells.lipid biosynthesis was measured in cultured chicken embryo cells after infection with fowlpox virus. between 24 and 72 h postinfection, fowlpox virus-infected cells incorporated less [14c]acetate and 3h2o into fatty acids and sterols than did mock-infected cells, demonstrating a virus-dependent inhibition of general lipid metabolism. two specific effects of fowlpox virus infection were an accumulation of c-4 alkylated sterol intermediates and inhibition of monounsaturated fatty acid biosynthesis ...19826287040
detection of infectious laryngotracheitis virus infected cells with cloned dna probes.a genomic library of infectious laryngotracheitis virus (iltv) dna bamh1 fragments was prepared and two cloned fragments were evaluated for their potential as probes for the detection of iltv infected cells. the virus was purified by a modified sucrose density gradient procedure for the isolation of pure iltv dna. a genomic library was constructed using bamh1-digested iltv dna and pgem7 as a vector. a 1.1 kb cloned bamh1 fragment of iltv dna was tested in a slot or dot blot assay for the detecti ...19921316798
occurrence of atypical fowlpox in poultry farms in kenya.atypical fowlpox occurred in several poultry farms in kenya. on two occasions layers had their eyes closed and egg production dropped. fowlpox virus was isolated from lesions on the inner surfaces of the closed eyelids. other chickens had lesions covered by yellow caseous necrotic material in the mouth, around the epiglottis, and in the trachea and choanae. typical proliferative cutaneous lesions were observed in birds of all ages in other flocks examined. fowlpox virus was recovered from both c ...1979230810
pathogenesis of fowlpox in laying hens.egg production dropped after hens were inoculated with fowlpox virus originally isolated from a natural mild infection. the drop started from the 2nd week and continued to the 5th week after inoculation. all birds developed focal lesions at the site of inoculation, and some developed secondary lesions. the drop in individual birds was related to the severity of lesions. birds challenged with fowlpox virus fifteen months after vaccination with pigeon pox vaccine were susceptible.1978209778
studies on poxvirus isolated from a magpig in avian poxvirus was isolated from a black-backed magpie in queensland. the virus produced pocks on the chorio-allantoic membrane of chicken embryos and lesions on the skin of chickens. comparison by passive haemagglutination test and neutralisation test indicated that the virus was related more closely to pigeonpox virus than to fowlpox virus.1977200213
odd-and even-numbered fatty acids. their contrasting behavior in normal and fowlpox virus-infected epithelium.upon infection with fowlpox virus, the amount of odd-numbered fatty acids in chick scalp epithelium shows a significant decrease compared with control values. this effect begins quite early and progresses throughout the period of infection. individual members of the odd-numbered family (c15--c27 inclusive) were quantitatively related to the group as a whole during most of the infection. experiments involving the administration of labeled acetate in vivo demonstrated an increase in the synthesis ...1977192305
oral immunization against pox. studies on fowl pox as a model.oral vaccination against fowl pox is both effective and harmless. a suitable vaccine strain is the attenuated hp-1 strain in the 200th to 400th tissue culture passage. for optimal immunization virus of the 200th to 270th passage level should be applied twice at an interval of 3 to 4 weeks. vaccination dose should contain 10(7.0)tcid50. chickens may be effectively immunized already at 5 days. immunity is against both homologous and heterologous virus and proves equally resistant to oral, cutaneo ...1976182584
fowlpox virus recombinants expressing the envelope glycoprotein of an avian reticuloendotheliosis retrovirus induce neutralizing antibodies and reduce viremia in chickens.eight stable fowlpox virus (fpv) recombinants which express the envelope glycoprotein of the spleen necrosis virus (snv) strain of reticuloendotheliosis virus (rev), an avian retrovirus, were constructed. these recombinants differ in the genomic location of the inserted genes, in the orientation of the insert relative to flanking viral sequences, and in the promoter used to drive expression of the env gene. of these variables, promoter strength seems to be the most crucial. the p7.5 promoter of ...19938388488
development of parthenogenetic membranes in double-yolked and injected chicken eggs.development of parthenogenetic eggs is expressed in a dark cornish stock by either membrane or embryo formation. double-yolked eggs have membranes developing in zero, one, or two yolks. the incidence of double-yolked eggs with two membranes was higher than expected when compared with the incidence of single-yolked eggs from the same hens. membrane formation was increased over that of the controls by injecting saline, ringer's solution, or ground crude membranes. yolk and membranes filtered throu ...1975166142
a smear technique for staining elementary bodies of elementary bodies of fowlpox virus were detected in smears from lesions of infected chorioallantoic membrane and from skin of infected birds stained by the giménez method.197660991
role of the tk+ phenotype in the stability of pigeonpox virus recombinant.insertion of foreign dna containing the e. coli gpt marker by homologous recombination in the pigeonpox virus (ppv) thymidine kinase (tk) gene and selection for the presence of this dna in the viral genome produced unstable recombinants after 3 plaque purifications. we highlight the persistence of duplicated tk dna sequences arising from single crossing over, due to the growth advantage of tk+ virus. restoration of the tk function by coinsertion of the vaccinia virus tk gene led to stable tk+ re ...19938394070
the demonstration of cell-mediated immunity in chickens vaccinated with fowlpox virus. 19853000113
protective immunity against avian influenza induced by a fowlpox virus recombinant.fowlpox virus, the prototypic virus of the genus avipoxvirus has a natural host range limited to avian species. as such, fowlpox virus provides a suitable candidate for the development of a species-specific recombinant viral vector. this paper reports the development of a fowlpox virus recombinant expressing the haemagglutinin molecule from a highly virulent avian influenza virus. on immunization of chickens and turkeys with the recombinant, protection is afforded against a lethal challenge with ...19882854339
role of complement in the pathogenicity of fowlpox virus infection in chickens and chicken embryos. 19882834595
avian pox: infection and immunity with quail, psittacine, fowl, and pigeon pox viruses.quail, chickens, and turkeys vaccinated with pigeon and fowl pox viruses were not protected against challenge of their immunity with quail pox virus and they developed severe cutaneous lesions of pox. when quail and chickens were vaccinated with quail pox virus and given pigeon and fowl pox challenge viruses, no protection was present. thus, quail pox virus had no immunologic relationship to pigeon and fowl pox viruses. psittacine pox virus applied as a vaccine in quail and chickens also failed ...19852579373
structural proteins of two different plaque-size phenotypes of fowlpox virus.structural polypeptides of two plaque-purified variant isolates of fowlpox virus differing in plaque morphology and size were examined by coomassie blue-staining and immunoblot analysis of purified virions. a total of 30 structural polypeptides were observed, ranging in molecular weight from 14,100 to 122,600. a late polypeptide of 36,400 molecular weight was quite prominent in the small-plaque clone but absent in the large-plaque clone. two other polypeptides, of 33,700 and 34,800 molecular wei ...19892549937
detection of fowlpox virus dna by in situ hybridization using a biotinylated situ hybridization was applied to detect fowlpox virus (fpv) dna in formalin-fixed paraffin-embedded sections of the skin from infected chickens by using a biotinylated probe and a streptavidin-alkalinephosphatase conjugate. the immunohistochemical examination was applied to compare the distribution of the fpv dna to that of related antigenic protein in serial sections. in the infected epithelial cells, fpv dna was detected in cytoplasmic inclusion bodies and in the rest of cytoplasm. likewis ...19902164391
role of humoral and cell-mediated immunity on the recovery of chickens from fowlpox virus infection. 19734355425
field and vaccine strains of fowlpox virus carry integrated sequences from the avian retrovirus, reticuloendotheliosis virus.for baculoviruses and herpesviruses, integration of transposons or retroviruses into the virus genome has been documented. we report here that field and vaccine strains of fowlpox virus (fpv) carry integrated sequences from the avian retrovirus, reticuloendotheliosis virus (rev). using pcr and hybridization analysis we observed that vaccine and field strains of fpv carry rev sequences integrated into a previously uncharacterized region of the right 1/3 of the fpv genome. long-range pcr, hybridiz ...19979281517
an improved dot-blot method for virus detection in chicken embryo fibroblast cultures.a simplified dot-blot procedure is described for the detection of fowlpox virus (fpv) in infected monolayers of chicken embryo fibroblasts (cef) cultured in 96-well microtiter plates. the relative resistance of dna to hot naoh, which hydrolyzes other macromolecules including rna and protein, was exploited to solubilize virus infected cells and denature intracellular dna in a simple, quick manner. moreover, there was no need to purify virus or isolate viral dna from cellular dna prior to dot blot ...19911849916
protection against marek's disease by a fowlpox virus recombinant expressing the glycoprotein b of marek's disease virus.fowlpox virus (fpv) recombinants expressing the glycoprotein b and the phosphorylated protein (pp38) of the ga strain of marek's disease virus (mdv) were assayed for their ability to protect chickens against challenge with virulent mdv. the recombinant fpv expressing the glycoprotein b gene elicited neutralizing antibodies against mdv, significantly reduced the level of cell-associated viremia, and, similar to the conventional herpesvirus of turkeys, protected chickens against challenge with the ...19921310755
in vivo effects of chicken myelomonocytic growth factor: delivery via a viral vector.we have constructed a recombinant fowlpox virus (fpv) that expresses chicken myelomonocytic growth factor (cmgf). administration of this construct (fp/cmgf) to 1-day-old chicks resulted in a marked and sustained increase in the number of circulating blood monocytes compared with chicks infected with the parental fpv strain (fp/m3). blood monocyte numbers were elevated within 4 days of fp/cmgf infection, reached maximal levels at day 9, and returned to normal levels by day 16. during the peak res ...19968609421
pathologic changes in chickens caused by intravenous inoculation with fowlpox virus.twenty chickens were inoculated intravenously with fowlpox (fp) virus, and clinical and pathological examinations were carried out chronologically. upon gross examination, miliary nodules scattered in the kidneys were observed from 10 to 18 days postinoculation (pi), as were papules on the skin and diphtheritic lesions on the mucous membrane of the upper respiratory tract. microscopically, characteristic fp lesions, composed of swelling and proliferation of cells with formation of bollinger bodi ...19892546531
immune response of chicks vaccinated with fowl pox virus vaccines by the feather follicle method. 19892546306
multiplication of fowlpox virus in chicken embryo fibroblastic cell cultures. 19704194789
in vitro cellular immunity to unrelated pathogens in chickens infected with fowlpox virus.peritoneal macrophages recovered from chickens 15 to 20 days after inoculation with fowlpox virus and showing a delayed hypersensitivity reaction against fowlpox antigens demonstrated an enhanced antimicrobial effect against fowlpox virus as well as unrelated viruses and bacteria. inoculation of normal chicken macrophage cultures with fowlpox virus resulted in approximately a 200-fold increase in virus titer by 96 h, whereas the virus showed less than a fourfold increase in macrophage cultures f ...19744366915
fowlpox virus in the sudan.a virulent fowlpox virus was isolated from a natural outbreak of the disease in the sudan. the virus was used for experimental transmission of the disease to susceptible chickens. scarification and intravenous methods were used to infect one-month-old chickens. scarification induced typical pox lesions at 5-7 days postinoculation, whereas intravenous injection induced only swelling of combs or wattles, at 10-11 days postinoculation, although neutralizing antibodies against fowlpox virus were det ...19806255929
effect of subcutaneous pox vaccination of young chicks on immune responses and weight gains.two fowl pox and two pigeon pox vaccines were administered subcutaneously in the dorsum of the neck of specific-pathogen-free (spafas) chicks at day of hatch in separate studies. treatment levels used were 1:2, 1:10, or 1:50 dilution of the recommended wing web dose. both pigeon pox vaccines and one fowl pox vaccine depressed body weight gains significantly by day 14. mean body weight gains of female chicks were less affected by pigeon pox vaccines than by fowl pox vaccines. the mean hemagglutin ...19816267579
differential diagnosis of infectious laryngotracheitis from other avian respiratory diseases by a simplified pcr procedure.a simple polymerase chain reaction (pcr)-based procedure was developed for the detection of avian infectious laryngotracheitis virus (iltv) in chicken trachea, chorio-allantoic membrane (cam), infected hepatoma cells and infectious cell culture supernatant. samples were prepared by dilution in distilled water. after boiling and low speed centrifugation, samples were used for pcr analysis with two primers without special labeling. the pcr analysis for ilt virus could be completed in less than 8 h ...19947714054
influence of dose and route of inoculation on responses of chickens to recombinant fowlpox virus vaccines.the influence of dose and route of inoculation on responses of chickens to vaccination with recombinant fowlpox viruses (rfpvs) expressing an influenza haemagglutinin (ha) (fpv-ha) and the infectious bursal disease virus (ibdv) vp2 antigen (fpv-vp2) has been evaluated. antibody responses to influenza and fowlpox virus were generated following vaccination via the wing web by subcutaneous inoculation or skin scarification. intranasal and conjunctival inoculation failed to induce antibodies to fpv ...19947801520
vaccination of chickens with a recombinant fowlpox virus containing the hemagglutinin-neuraminidase gene of newcastle disease virus under the control of the fowlpox virus thymidine kinase promoter.when chickens were vaccinated with a recombinant fowlpox virus (fpv) containing the newcastle disease virus (ndv) hemagglutinin-neuraminidase (hn) cdna under the control of the thymidine kinase (tk) promoter and inserted into the fpv tk gene, the fpv antibody response to the recombinant virus was similar to the response to vaccination with standard fpv, and the recombinant virus protected chickens against challenge with virulent fpv. while the presence of the ndv hn cdna was demonstrated in the ...19947889464
applications and statistics for multiple high-scoring segments in molecular sequences.score-based measures of molecular-sequence features provide versatile aids for the study of proteins and dna. they are used by many sequence data base search programs, as well as for identifying distinctive properties of single sequences. for any such measure, it is important to know what can be expected to occur purely by chance. the statistical distribution of high-scoring segments has been described elsewhere. however, molecular sequences will frequently yield several high-scoring segments fo ...19938390686
effect of complement depletion by cobra venom factor on fowlpox virus infection in chickens and chicken embryos.the course of infection with an attenuated strain of fowlpox virus (fpv), which is known to induce antibody-independent activation of complement via the alternative pathway, was investigated in 1- to 3-day-old chickens and 14-day-old chicken embryos by treatment with cobra venom factor (cvf). cvf was found to inhibit complement activity transiently via the alternative pathway but not via the classical pathway. in chickens treated with cvf, virus growth in the skin was enhanced, and pock lesions ...19863003397
comparative immunological and genomic characterization of fowlpox virus isolates.chickens infected with fowlpox virus (fpv) ivri vaccine strain and two field isolates collected from clinical cases of disease (bareilly isolate and panchmahal isolate) produced humoral antibody response after 2nd week post-infection, with a noticeable variation in degree of immune response. serum antibody titre peaked at 4th week post-infection with a titre of 25,600, 25,600 and 51,200 being detected in elisa and neutralization index of 2.75, 2.43 and 3.12 in serum neutralization test (snt) wit ...19968698401
characterization of a recombinant fowlpox virus expressing the native hexon of hemorrhagic enteritis virus.the structure of the icosahedral adenovirus capsid is highly conserved among adenoviridae. in its native form, the hexon is the major capsid protein. the nascent hexon requires the 100 kda folding protein to fold into its native, trimeric form. the hexon and 100 kda folding protein were co-expressed in a fowlpox virus (fpv) vector and in the recombinant fpvs (rfpvs) in which the hexon and 100 kda folding protein genes are cloned head to tail, the native hexon could be detected with indirect immu ...200111450954
immunity to mexican h5n2 avian influenza viruses induced by a fowl pox-h5 recombinant.the presence of highly pathogenic h5n2 avian influenza in domestic poultry in mexico that is not being eradicated by conventional depopulation methods constitutes an imminent problem for poultry producers and agricultural authorities in the united states. the present report considers the candidate vaccines available to h5n2 influenza virus and establishes that a fowl pox-h5 recombinant can provide protection from lethal mexican h5n2, and prevent shedding in the feces and transmission to contact ...19968790900
cytotoxic t lymphocyte response in chickens immunized with a recombinant fowlpox virus expressing marek's disease herpesvirus glycoprotein b.previously, we demonstrated that cytotoxic t lymphocytes (ctls) from mhc: b19b19 and mhc: b21b21 chickens inoculated with a non-oncogenic marek's disease virus (mdv) vaccine strain, sb-1/12 can lyse syngeneic reticuloendotheliosis virus (rev)-transformed cell lines expressing mdv pp38 or gb genes. in this study, we report the characterization of mdv gb-specific ctls in chickens immunized with recombinant fowlpox virus expressing mdv gb gene (rfpv-gb). spleen cells from rfpv-gb inoculated chicken ...19989618870
activation of chicken alternative complement pathway by fowlpox virus-infected cells.fresh normal chicken serum (ncs) which lacked virus-neutralizing antibody to fowlpox virus (fpv) was found to inhibit the appearance of the cytopathic effect of the virus, virus growth, and plaque formation in chicken embryo cells. immunofluorescent examination revealed the deposition of the third component of complement (c3) on fpv-infected chicken embryo cells incubated with fresh ncs. the inhibitory activity of fresh ncs on viral cytopathic effect was independent of the ca2+ ion and was abrog ...19836315584
fowlpox virus host range restriction: gene expression, dna replication, and morphogenesis in nonpermissive mammalian cells.fowlpox virus (fpv), type species of the avipoxvirus genus, causes a slow-spreading pox disease of chickens. following infection of mammalian cells there is no evidence of productive replication of fpv although cytopathic effects are induced and fpv recombinants have been shown to express foreign genes from vaccinia virus early/late promoters. here we report results of a study to investigate the expression of fpv genes, the replication of fpv genomic dna, and any ultrastructural changes in mamma ...19938212580
vaccination of chickens with live fowl pox (fp) vaccine in fowl pox (fp) vaccine was adjuvanted in oil just prior to the subcutaneous (sc) vaccination of one day old chicks and adult chickens. the birds were challenged by the wing web (ww) method and absence of "takes" were considered as protection. on 21 day post challenge, 90%-100% of the chicks or chickens were protected while on day 9 post challenge 60% were protected. full protection of the live-in-oil adjuvanted vaccine is probably somewhat delayed as compared to protection endowed by the liq ...19938284967
infectious bursal disease virus structural protein vp2 expressed by a fowlpox virus recombinant confers protection against disease in chickens.two fowlpox virus recombinants were constructed which expressed the host-protective antigen, vp2, of infectious bursal disease virus (ibdv). recombinant fpv-vp 2.4.3 contained the gene for the vp 2-vp4-vp3 polyprotein under the control of the vaccinia virus late promoter p.l 11 inserted within the thymidine kinase (tk) gene of fpv. in infected chicken embryo skin (ces) cells vp2 and vp3 proteins were correctly processed from the polyprotein precursor molecule. recombinant fpv-vp2 contained only ...19938394069
a recombinant fowlpox virus expressing the envelope antigen of subgroup a avian leukosis/sarcoma virus.a recombinant fowlpox virus (fpv) was constructed by inserting cloned sequences from schmidt-ruppin subgroup a avian sarcoma virus coding for the viral envelope (env) antigen into a nonessential region of fpv dna downstream from a synthetic promoter. sera from chickens hyperimmunized with the recombinant fpv neutralized the infectivity of the homologous subgroup a virus (rcasbp/ap) but only weakly neutralized the infectivity of rous sarcoma virus, another subgroup a avian leukosis virus. similar ...19958561735
glycoproteins h and l of marek's disease virus form a hetero-oligomer essential for translocation and cell surface expression.glycoproteins h and l form a hetero-oligomeric complex (gh-l) which plays an important role in virus entry to host cells and cell-to-cell infection in herpesviruses. interaction of gh and gl is considered to be critical for the biological function of these two glycoproteins. to investigate the interaction of mdv gh and gl, both gh and gl were expressed in in vitro cell culture systems using indirect immunofluorescence assay with gh and gl antibodies. the results suggested that co-expression of g ...200111448035
protective effect of avian myelomonocytic growth factor in infection with marek's disease virus.marek's disease virus (mdv) is a herpesvirus that induces t lymphomas in chickens. the aim of this study was to assess the role of the macrophage activator chicken myelomonocytic growth factor (cmgf) in controlling mdv infection. b13/b13 chickens, which are highly susceptible to md, were either treated with cmgf delivered via a live fowlpox virus (fp/cmgf) or treated with the parent vector (fp/m3) or were left as untreated controls. seven days later, when challenged with the very virulent rb-1b ...200211773382
fowlpox virus structural protein immunogens and characterization of single band polypeptide.a fowlpox virus isolate obtained from an outbreak of disease in a vaccinated poultry flock was propagated in chicken embryo fibroblast cell culture. analysis of purified virus polypeptide on 7.5-15% gradient polyacrylamide gel revealed 45 structural polypeptides after coomassie blue staining. the mol.wt. of polypeptides ranged between 225.53 and 10.50 kda with total mol.wt. of 2650 kda. variable numbers of immunogenic virion polypeptides were detected in immunoblot with fowlpox virus infected ch ...19968698419
identification and phylogeny of a non-specific endonuclease gene of white spot syndrome virus of shrimp.white spot syndrome virus (wssv) is a taxonomically unclassified virus which causes a disease in shrimps worldwide. a 936 bp long open reading frame (orf) was found on a 7.2 kb hindiii fragment of the dna genome of wssv located adjacent to the ribonucleotide reductase small subunit gene. this putative orf showed homology to prokaryotic and eukaryotic endonucleases, which contain a non-specific endonuclease motif. alignment with viral and eukaryotic endonuclease orfs revealed that most catalytica ...200111778701
evaluation of a commercial modified live virus fowl pox vaccine for the control of "variant" fowl poxvirus infections.three-week-old specific-pathogen-free chickens were vaccinated with either a commercial modified live virus fowl pox vaccine or five "variant" poxvirus field isolates. immunity engendered by the commercial modified vaccine or field isolates was challenged with either the variant isolates or commercial modified vaccine virus. the commercial modified vaccine did not adequately protect vaccinates against challenge with the variant isolates. the percentages of vaccinated chickens protected following ...19968883788
comparative evaluation of cell culture-adapted and chicken embryo-adapted fowl pox vaccine strains.two types of vaccines, chicken embryo adapted (vacce) and cell culture adapted (vaccc), were tested for their efficacy to elicite the immune response in birds vaccinated at 2 and 8 wk of age. the cell-mediated immune response studied by blastogenesis assay showed that birds vaccinated at the second week of age by both vacce and vaccc vaccines had significant increase in t-lymphocyte count at 21 days postvaccination (pv) and 7 days postchallenge (pc), whereas in birds vaccinated at 8 wk of age, a ...199910216755
antibody detection-based differential elisa for ndv-infected or vaccinated chickens versus ndv hn-subunit vaccinated chickens.with the advent of subunit vaccines for microbial diseases it is becoming increasingly important to be able to differentiate naturally infected animals from those vaccinated with the corresponding subunit vaccine. for avian viruses such as newcastle disease virus (ndv), a whole virus-based elisa cannot make such a differential diagnosis since in both cases the antisera would react with the whole virus. the nucleocapsid protein (np) gene of the ndv hitchner b1 strain was cloned, sequenced and exp ...199910227123
rescue of newcastle disease virus from cloned cdna: evidence that cleavability of the fusion protein is a major determinant for virulence.a full-length cdna clone of newcastle disease virus (ndv) vaccine strain lasota was assembled from subgenomic overlapping cdna fragments and cloned in a transcription plasmid between the t7 rna polymerase promoter and the autocatalytic hepatitis delta virus ribozyme. transfection of this plasmid into cells that were infected with a recombinant fowlpoxvirus that expressed t7 rna polymerase, resulted in the synthesis of antigenomic ndv rna. this rna was replicated and transcribed by the viral np, ...199910233962
recombinant fowlpox virus vaccines against australian virulent marek's disease virus: gene sequence analysis and comparison of vaccine efficacy in specific pathogen free and production chickens.we have cloned and sequenced the glycoprotein genes gb, gc and gd of the australian virulent marek's disease virus (mdv) isolate woodlands no. 1. the glycoprotein gb and gc sequences were identical to the homologs of other virulent mdv type 1 strains, and the glycoprotein gd sequence contained only one unique amino acid substitution. recombinant fowlpox viruses (rfpvs) expressing the mdv glycoprotein genes were constructed and their efficacy as vaccines was evaluated in specific pathogen free (s ...19979255932
development of a monoclonal blocking elisa for the detection of antibodies against fowlpox provide a fast and easy method to detect antibodies against fowlpox virus (fwpv) particularly in high numbers of chicken sera we established a monoclonal blocking enzyme-linked immunosorbent assay (elisa). we chose two different monoclonal antibodies (mab), anti-fwpv 3d9/2b3 and anti-fwpv 8f3/2e11, which are both directed against the 39-kda protein of fwpv strain hp-1. the blocking elisa depends on the blocking of mab binding to solid-phase antigen in the presence of positive serum. for an ep ...200211911587
potential use of cytokine therapy in poultry.newly hatched chickens are highly susceptible to infection during the first 2 weeks of life. the utilisation of cytokines as therapeutic agents in livestock animals, in particular poultry, has become more feasible with the recent cloning of cytokine genes and the progression of new technologies such as live vectors. we have constructed a live recombinant fowlpox virus (fpv) that expresses chicken myelomonocytic growth factor (fp/cmgf). administration of fp/cmgf to chicks resulted in a marked and ...19989656454
embryo vaccination of turkeys against newcastle disease infection with recombinant fowlpox virus constructs containing interferons as adjuvants.recombinant fowlpox viruses (rfpv) expressing the fusion and hemagglutinin-neuraminidase glycoproteins of newcastle disease virus (ndv) as well as chicken type i interferon (ifn) or type ii ifn were used to vaccinate specific pathogen-free (spf) turkeys in ovo. no significant changes in the hatchability, survival rate, performance and weight gain were observed after vaccination with the rfpv vaccines in comparison to diluent-inoculated embryos. the rfpv-ndv-ifn-ii construct induced the onset of ...199910519931
a recombinant fowlpox virus vaccine expressing glycoprotein b gene from cvi988/rispens strain of mdv: protection studies in different chickens.recombinant fowlpox virus (rfpv) was constructed to express glycoprotein b (gb) gene from cvi988/rispens strain of marek's disease virus (mdv). the rfpv-gb/r alone and in combination with herpesvirus of turkey (hvt) preparations were evaluated for their protective efficacy against challenge with very virulent mdv strains md5 and rb1b in different chickens. the rfpv-gb/r alone induced protection comparable to that by hvt vaccines in both ab- spf chickens and ab+ production chickens. significant p ...199910696446
vaccinating chickens against avian influenza with fowlpox recombinants expressing the h7 evaluate the vaccine efficacy of a fowlpox virus recombinant expressing the h7 haemagglutinin of avian influenza virus in poultry.200010736685
failure of a recombinant fowl poxvirus vaccine containing an avian influenza hemagglutinin gene to provide consistent protection against influenza in chickens preimmunized with a fowl pox vaccine.vaccines against mildly pathogenic avian influenza (ai) have been used in turkeys within the united states as part of a comprehensive control strategy. recently, ai vaccines have been used in control programs against highly pathogenic (hp) ai of chickens in pakistan and mexico. a recombinant fowl pox-ai hemagglutinin subtype (h) 5 gene insert vaccine has been shown to protect specific-pathogen-free chickens from hp h5 ai virus (aiv) challenge and has been licensed by the usda for emergency use. ...200010737653
fowlpox virus encodes nonessential homologs of cellular alpha-snap, pc-1, and an orphan human homolog of a secreted nematode protein.the genome of fowlpox virus (fwpv), type species of the avipoxviridae, is considerably rearranged compared with that of vaccinia virus (the prototypic poxvirus and type species of the orthopoxviridae) and is 30% larger. it is likely that the genome of fwpv contains genes in addition to those found in vaccinia virus, probably involved with its replication and survival in the chicken. a 7,470-bp segment of the fwpv genome has five open reading frames (orfs), two of which encode ankyrin repeat prot ...19989658122
vaccines protect chickens against h5 highly pathogenic avian influenza in the face of genetic changes in field viruses over multiple years.inactivated whole avian influenza (ai) virus vaccines, baculovirus-derived ai haemagglutinin vaccine and recombinant fowlpoxvirus-ai haemagglutinin vaccine were tested for the ability to protect chickens against multiple highly pathogenic (hp) h5 ai viruses. the vaccine and challenge viruses, or their haemagglutinin protein components, were obtained from field ai viruses of diverse backgrounds and included strains obtained from four continents, six host species, and isolated over a 38-year-perio ...200010799788
characterization of poxviruses from forest birds in hawaii.two strains of avian pox viruses were isolated from cutaneous lesions in hawaiian crows (corvus hawaiiensis) examined in 1994 and a third from a biopsy obtained in 1992 from an infected bird of the apapane species (himatione sanguinea) by inoculation of the chorioallantoic membranes (cam) of developing chicken embryos. the resulting proliferative cam lesions contained eosinophilic cytoplasmic inclusion bodies characteristic of pox virus infection. the pathogenicity of these three viruses in dome ...200010813603
[a recombinant fowlpox virus expressing the fusion protein of newcastle disease virus strain f48e8 and its protective efficacy].the transfer vector pfgf1175-1 was constructed by insertion the fusion protein gene of newcastle disease virus (ndv) f48e8 strain into the insertion vector pfg1175-1, downstream of p7.5 promotor, and then transfected chicken embryo fibroblast (cef) cell cultures which had been infected with fowlpox virus (fpv) chinese vaccine strain 282e4 for 3-4 hours. recombinant fpv with blue plaques were selected and purified in cef cell culture laid agar containing x-gal. the recombinant fpv named rfpv-ndf ...200011191764
[cloning of glycoprotein b gene from strain rispens of marek's disease virus and construction of recombinant fowlpox virus].purified dnas from chicken embryo fibroblast (cef) cultures infected with mdv strain rispens were used as templates. specific fragment with the size of about 2.9 kb was successfully amplified through polymerase chain reaction(pcr) and identified to be gb gene of mdv by dot blot hybridization with a digoxigenin-labelled mdv gb specific oligonucleotide probe. the gb gene from strain rispens was cloned into puc19 and fpv insertion vector pfg1175-1 to construct plasmid pmgb and pfgbr1775-1 respectiv ...199912555423
construction and characterization of a fowlpox virus field isolate whose genome lacks reticuloendotheliosis provirus nucleotide sequences.fowlpox virus (fwpv) has been isolated from vaccinated chicken flocks during subsequent fowlpox outbreaks that were characterized by a high degree of mortality and significant economic losses. this inability of current vaccines to induce adequate immunity in poultry could be reflective of an antigenic and/or biologic distinctiveness of fwpv field isolates. in this regard, whereas an infectious reticuloendotheliosis virus (rev) provirus is present in the majority of the field viruses' genomes, on ...200516252496
[selection of recombinant fowlpox virus coexpressing hiv-1 gag-gp120 and il-6].to construct the recombinant fowlpox virus (rfpv) coexpressing hiv-1 gag-gp120 and hil-6.200516261213
immunogenicity of fowlpox virus expressing the avian influenza virus h5 gene (trovac aiv-h5) in cats.vaccination of cats with fowlpox virus expressing the avian influenza (ai) virus h5 hemagglutinin gene (trovac ai) resulted in detectable hemagglutination inhibition (hi) antibody responses to the homologous a/turkey/ireland/1378/83 (h5n8) (a/tky/ire/83) ai virus antigen. the hi antibody responses to heterologous a/chicken/indonesia/7/03 (h5n1) (a/ck/indonesia/03) ai virus antigen were also detected in all vaccinated cats, but only after booster vaccinations. the vaccine described in this study ...200516275953
[construction, genetic stability and protective efficacy of recombinant fowlpox virus expressing hemagglutinin gene of h5n1 subtype avian influenza virus].construction, genetic stability and protective efficacy of a recombinant fowlpox virus expressing hemagglutinin (ha) gene (rfpv-ha) of h5 subtype avian influenza virus were conducted. the results indicated that the recombinant fowlpox virus was obtained and purified by blue plaque selection. ha expressed by rfpv-ha was identified by indirect immunofluorescence array. the rfpv-ha could express reporter gene lacz and ha gene after fifteen successive passages in chicken embryo fibroblast. the rfpv- ...200316276892
progress in recombinant vaccine development against coccidiosis. a review and prospects into the next millennium.the increasing problems encountered by the poultry industry, despite the extensive use of drugs, have emphasised the need for an immunological solution for the economic damage caused by the eimeria parasite. although immunity develops relatively fast following a natural infection, to induce protection by using parasite extracts or single antigens appears more difficult. nevertheless, the development of a vaccine based on defined antigens seems the best solution in the long run. at the vith inter ...19989724883
[recombinant fowlpox virus expressing ha from subtype h9n2 of avian influenza virus and its protective immunity against homologous challenge in chickens].the hemagglutinin (ha) gene from the aiv, a/chicken/china/f/1998(h9n2), was amplified with the rt-pcr technique and directionally inserted into transferring vector 1175, resulted in recombinant transferring vector 1175ha. in order to generate recombinant fowlpox virus expressing ha(rfpv-ha), the recombinant transferring vector 1175ha was used to transfect the chicken embryo fibroblasts(cef) pre-infected with wide type fowlpox virus. then, by selection of blue plaques on the cef overlaid with aga ...200212557550
detection of specific reticuloendotheliosis virus sequence and protein from rev-integrated fowlpox virus strains.the detection is described of reticuloendotheliosis virus (rev) protein in tissue culture of chicken embryonated cells (cefs) infected with field isolates of fowl poxvirus (fpv). by the polymerase chain reaction (pcr), five out of the six field isolates, but two out of the seven vaccine strains of fpv, were found to have had a 291 bp repeat sequence of rev-ltr integrated in their genomic dna. an immunofluorescence (if) method was employed using a monoclonal antibody (mab) known to specify strain ...200312757926
fowlpox virus infection causes a lymphoproliferative response in chickens.while attenuated fowlpox virus (fpv) strains are widely used for vaccination of chickens and turkeys for prevention of fowlpox, recombinant fpv expressing various foreign genes have been evaluated for their ability to offer protection against various diseases in poultry as well as mammals. little is known regarding the cell-mediated immune responses to fpv infection. in this study, immune response in chickens infected with a virulent and a vaccine strain of fpv were compared by a lymphoprolifera ...200312828873
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