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Pigeon paramyxovirus type 1 (PPMV-1) is a serious pathogen facing the pigeon industry. Thus, this study aimed to preparation and evaluation of two inactivated vaccines using Carbopol and Aluminum hydroxide-based adjuvants to control such a problem. A total of 45-four weeks old, apparently healthy pigeons were allocated into 3 groups (15 birds each) as follow: group 1 (G1) received 0.5 ml, S/C Carbopol adjuvanted vaccine, group 2 (G2), received 0.5 ml S/C of aluminum hydroxide-based vaccine, group 3 (G3) received 0.5 ml S/C sterile saline and kept as control group. Five serum samples were obtained from each bird weekly post vaccination to measure anti-PPMV-1 antibodies using HI test. At 35 days post immunization, all vaccinated pigeons were challenged with 20µl containing 106 EID50/bird of PPMV-1 YA/14 strain by eye drop route, all pigeons were kept under observation for 10 days during the observation period any clinical signs or moralities were recorded also, cloacal swabs were collected 4-, 7- and 10-days post challenge to measure the shedding level. The potency test revealed that the prepared inactivated vaccine (PPMV-1) with synthetic polymeric adjuvants were potent and efficient. By studying the elicited serum antibody dynamics in vaccinated pigeon using HI test showed that antibody, the beak antibody titer reached by the 4th week post immunization (6 and 5 log 2) for both G1 and G2 respectively (but G1 is significantly increase than G2) and continued to the 5th week where it reaches 6.5 and 5.6 log2 for both groups in order. (G1 is significantly increase than G2), which indicated that the PPMV-1 inactivated vaccine in both G1 and G2, results in systemic adjuvant activity, including a long-lasting protective immune response after a single dose administration without any adverse reaction. G1 and G2 showed the lowest shedding level that was zero at the 10th day post challenge and the overall reduction level of both vaccinated groups was 4.9 and 4.5 for both G1 and G2, respectively. However, the prepared inactivated PPMV-1 Carbopol based vaccine is safe and could significantly poses the immune response more effectively than the aluminum hydroxide-based vaccine. [ABSTRACT FROM AUTHOR]

Vaccines against the virulent Newcastle disease virus (NDV) are broadly existing and can provide protection; nevertheless, better immunization practices are required to avoid clinical disease and limit virus circulation. This study evaluating the immunogenicity and protective efficiency of locally prepared clone 30 live-attenuated vaccine against the challenge impact of virulent NDV genotype IV and genotype VIId prevalent in Egypt in comparison with the commercially prepared live Lasota vaccine as a positive control group. The efficacy of the vaccine was evaluated based on the antibody titer, protection rate, oropharyngeal, and cloacal shedding. Therefore, 150 one day old specific pathogen free chicks (SPF) were divided in to three groups 50 bird per group (G), G1and G2 received 100 µl containing 6 log10 EID50 via the oculo-nasal route of clone 30 vaccine and lasota vaccine in order, while G3 (unvaccinated) received sterile saline at the same route and dose. On day 21 post vaccination (pv) 40 bird from each group were challenged with a dose of 6.5 log10/ml EID50 intramuscular per bird for both genotype IV and genotype VIId (20 bird/genotype virus), the other 10 birds left from each group were kept separate for antibody level monitoring for the 6th week pv. Results revealed that, during vaccine preparation, the clone 30 virus showed a high virus titer when propagated in SPF embryonating chicken eggs (SPF-ECEs), which reached 1012/EID50/ml. The protection rate due to the clone 30 vaccine and the lasota vaccine was alike and showed 75% and 70% against challenge with genotype IV and genotype VIId, respectively, there were no significant differences (p > 0.05) between the antibody titer produced by the clone 30 vaccinated group and lasota group. Both the clone 30 and lasota vaccines showed nearly similar levels of oropharyngeal and cloacal shedding. The results clarify that, although there were no detected differences between the immune response and the protective efficacy of clone 30 vaccine and lasota vaccine but, the use of clone 30 vaccine is still advantageous for its superior immunogenicity and low post-vaccinal reaction, which will make the clone 30 vaccine suggestive for primary immunization, especially in immunologically naive birds. In conclusion, the prepared Clone 30 vaccine in the current study is safe for chicks and can be used as an effective vaccine against the circulating NDV. [ABSTRACT FROM AUTHOR]

Avian influenza virus (AIV) poses a serious problem among poultry production sector, low pathogenic avian influenza H9N2 (LPAI H9N2) has been widely spread globally inducing indirect huge economic losses and it considered as a hidden threaten due to its immunosuppressive impact on birds. Therefore, the current work objectives were the molecular detection of the circulating AI H9N2 field strain in Egypt during 2022-2023 with pathogenicity testing of the recovered virus in specific pathogen free (SPF) one day old chicks. Out of 10 suspected tracheal samples that have been collected from different broiler chicken farms in Al Qalyubia governorate only 7 (70%) samples were positive by Reverse transcription Polymerase chain reaction (RT-PCR). The strain that showed a high reproductive ability and high egg infective dose 50 (EID50) (109/μl) on ECE via allantoic sac has been selected for pathogenicity testing in SPF chicks. For pathogenicity testing, 60 SPF chicks were allocated into two groups 30 birds each. G1and G2 were inoculated via oculo-nasal route with 100 μl containing 1x 106 EID50/μl virus and 100μl sterile normal saline, respectively. During the experimental time (15 days), no mortalities were recorded in the two groups. The observed clinical signs were mild (ruffled feathers, and depression) in G1, but no clinical signs were observed in G2. During the experiment 3 birds per group were ethically slaughtered to observe the postmortem (PM) and histopathological lesions at 3, 5, 7, 10 and 14 days post-infection (dpi). The observed PM lesions were mild tracheitis, mild pneumonia, subcapsular hemorrhage in liver, enlargement of the spleen, mild atrophy in the pancreas, hemorrhage in the thymus, severe nephritis, and nephrosis with distended ureters with ureates but no macroscopic lesions were detected in the bursa of Fabricius. The virus tropism not restricted only to respiratory, renal, and gastrointestinal tract, but also to the liver, pancreas, and thymus. In conclusion, continuous molecular detection, with pathogenicity testing of circulating AIV is recommended. The authors recommend further full H9 sequence to perform cladogram to the currently tested strain. [ABSTRACT FROM AUTHOR]

Avian leukosis virus (ALV) is an oncogenic contagious virus infecting different avian species. This study aims to molecularly detect the circulating strains of ALV in various chicken and duck farms at different Egyptian governorates. Freshly dead birds were exposed for postmortem examination (PM) then samples were processed for histopathological examination as well as molecular detection of ALV using qRT-PCR and sequence analysis of the envelope glycoprotein gene (gp85) surface protein antigen with detection of recombination events that might be found between the detected strains. PM revealed the existence of diffuse enlargement of most internal organs, and in some cases, nodular enlargement was observed. Histopathological investigation showed myeloid cells infiltration of eosinophilic granular cytoplasm in the examined tissues. Five molecularly positive samples were sequenced and submitted in the GenBank with accession numbers MZ614719, MZ614720, MZ614721, MZ614722, and MZ614723. The phylogenetic tree construction based on the sequenced gp85 gene revealed that all Egyptian isolates were nearly arranged in a single branch despite the year of collection and were phylogenetically distant from other sequences. In general, studies concerning the genetic diversity of gp85, and the recombination events concluded that the ALV-J virus is a wide host range involving both chicken and ducks. Because ALV causes serious financial problems to threaten poultry production and neither vaccines nor treatment tools are now available for ALV prevention and control, periodical molecular monitoring with whole genome sequence and analysis for the circulating strains with ethical eradication of the positive birds are recommended to overcome such a problem. [ABSTRACT FROM AUTHOR]

Control of pigeon paramyxo virus infection relays on the production of a vaccine that is able to protect the birds from the lethal virulent infection as well as reducing shedding level to prevent virus circulation in the environment. In the current study inactivated vaccine was prepared from the recent field isolate (PPMV-1 YA/14) which is extensively characterized and identified. The vaccine was prepared in two formulas. The aluminum hydroxide gel (given S/C and I/M) and the oil adjuvanted formula. Evaluation of the 2 formulas revealed that the gel-based formula gave a higher antibody titer than the oil-based preparation during the course of the vaccination period and after challenge. The cellular immune response was also evaluated by the qRT-PCR analysis of the IFN-γ transcripts and it was found that the oil-based formula gave a high fold change than the gel-based formula although it was not reflected in decreasing the shedding level. Studying the shedding level by the EID50 and qRT-PCR of the cloacal swabs after challenge revealed that the gel-based formula administrated S/C gave lesser degree of shedding than the oil-based formula. In conclusion the gel-based formula of the vaccine prepared from the recent characterized PPMV-1 YA/14 isolate could protect pigeon from lethal infection with the virulent virus and could reduce but not eliminate the shedding level. [ABSTRACT FROM AUTHOR]