To develop a mucosal inactivated vaccines for Newcastle disease (ND) and H9N2 viruses to protect against these viruses at sites of infections through mucosal immunity. In this study, we prepared two new formulations for mucosal bivalent inactivated vaccine formulations for Newcastle and Avian Influenza (H9N2) based on the use of nanoparticles and polymer adjuvants. The prepared vaccines were delivered via intranasal and spray routes of administration in specific pathogen-free chickens. Cell-mediated and humoral immune response was measured as well as challenge trial was carried out. In addition, ISA71 water in oil was also evaluated. Our results showed that the use of spray route as vaccination delivery method of polymer and nanoparticles Montanide™ adjuvants revealed that it enhanced the cell mediated immune response as indicated by phagocytic activity, gamma interferon and interleukin 6 responses and induced protection against challenge with Newcastle and Avian Influenza (H9N2) viruses. The results of this study demonstrate the potentiality of polymer compared to nanoparticles adjuvantes when used via spray route. Mass application of such vaccines will add value to improve the vaccination strategies against ND virus and Avian influenza viruses.

Fowl adenoviruses are opportunistic emerging viruses that spread widely in fowls, infecting birds of all ages, including young broiler chicks. This study aims to genotype the current adenovirus strains associated with inclusion body hepatitis hydropericardium syndrome (IBH-HPS) among infected broilers in Upper Egypt and to evaluate their pathogenic features. In 2024, 100 tissue samples were collected across Assiut and Sohag governorates in Upper Egypt for genetic characterization and pathogenicity evaluation. FAdVs were detected in 22% (11/50) of flocks. Typical FAdV lesions of dead embryos were observed after seven days post egg inoculation. Regarding the PCR assay of the hexon gene, only 8 of 30 samples were confirmed positive at 897 bp, yielding a 26.6% positivity rate. The remaining samples were considered negative using established RT-qPCR protocols for other viral pathogens. Partial sequencing of the hexon gene revealed that FAdV isolates (n = 4) clustered within FAdV species-D serotype 2/11, as determined by phylogenetic analysis. The four isolates shared (98–99%) and (94–100%) nucleotide and amino-acid similarities to FAdV-D of Israeli strains (2019–2020) and contemporary Egyptian isolates (2022), respectively, and low genetic divergence (54–81%) in comparison with other documented species. The amino acid sequence alignment and 3D structure indicate that the four immunogenic HVRs are located in the L1 region of the hexon protein, and that the highly conserved ⁹¹GQMTT⁹⁵, a specific region for FAdV-D serotype 2/11, is present. Regarding pathogenicity, the gross and histopathological findings observed clearly demonstrate the systemic pathogenicity of FAdV-2/11 in the infected group, with a final mortality rate of 30% at seven days post-infection (dpi). The FAdV DNA in hepatic tissues and cloacal swabs was confirmed by the PCR method at 3 dpi and 5 dpi. These results emphasize the circulating of FAdV-2/11 species D in Upper Egypt and highlight the significant need for a single inactivated vaccine that effectively targets the relevant FAdV serotypes to achieve broader and more efficient protection.

Background and Aim: One strategy that can be used to stabilize vaccines is to convert them into a dry powder. This can protect the integrity of the active ingredients as well as vaccine antigenicity during manufacture, storage, and transport. This study highlights the potent adjuvant activity of Carbopol® when used alone to stabilize live-attenuated Newcastle disease virus (NDV) vaccines or when used in a formulation together with skimmed milk. Tolerability and potency of these formulations were compared with those obtained from other local live NDV vaccines produced locally by the Veterinary Serum and Vaccine Research Institute. Materials and Methods: We evaluated the cellular and humoral immune responses to a locally prepared, live-attenuated LaSota virus vaccine. Vaccine formulations were stabilized with Carbopol® 940 alone or in combination with skimmed milk. Results: Our results indicate that the use of Carbopol® 940 alone to stabilize a live-attenuated LaSota vaccine resulted in enhanced cellular and humoral immunity. The antibody titer was prolonged through the 6th week post-vaccination (5.0 log2). Full (100%) protection was observed in response to challenge with very virulent NDV at day 21 after vaccination; there were no clinical signs or lesions on examination. Addition of Carbopol® 940 to the live-attenuated vaccine formulation resulted in a more compact, stable, and high-quality lyophilized cake after freeze-dried lyophilization compared with that produced by stabilization with skimmed milk alone. Conclusion: Our data suggest that Carbopol® 940 may improve clinical responses to live-attenuated vaccines.

Veterinary Serum and Vaccine Research Institute (VSVRI ) objected to produce highly efficient vaccines from reference or local isolates according to the international specifications for protection of animals and poultry against different diseases, in addition to preparation of combined vaccines, to save effort, time and money. VSVRI produces different types of vaccines as live attenuated viral poultry vaccines, live attenuated viral animal vaccines , live attenuated Bacterial animal vaccines and Inactivated viral animal vaccine.These vaccines are subjected to quality assurance through six methods with different techniques.Validity and measurement uncertainty for results were applied in the evaluation of results of the following: Titration of virus content using egg inoculation through Chorioallantoic Membrane (CAM) ,Intra-allantoic (IA) and Tissue Culture (TC) .Determination of antibody titer using ELISA, HI and VNT technique. Finally, Enumeration of aerobic bacterial count for living attenuated Bacterial vaccine by culture technique. Homogeneity and stability results for all types of vaccines were accepted criteria according to TS/ ISO 22117.The reproducibility component of TC technique higher while the Bias was lower than other different routes of the egg inoculation. In conclusion, the accuracy of TC technique is better than egg inoculation technique which will reflect on the measurement of uncertainty. There is no significance change of the final measurement uncertainty of different routes of egg inoculation. While there is variance between bias accuracy and reproducibility precision due to the equation of measurement of uncertainty depend on all process performed in test accuracy and precision.

| The current study was conducted to evaluate the adjuvanted aerosol vaccination of pigeon pox vaccine (PPV) with Gel 01 in comparison with feather follicle non adjuvanted route of vaccination. In order to determine the best aerosol field dose of PPV, challenge was done for 3 groups of pigeon (group no 2, 3 and 4) aerosolly vaccinated with non adjuvanted prepared live attenuated Vero cell tissue culture adapted PPV different field dose ( Log 10 2,5, 3.5 , and 4.5 TCID 50 ) the protection percent were 75%, 80% and 80% respectively as field dose of 10 3.5 TCID 50 was the field dose of choice to be used with different concentrations of Gel 01 adjuvant. Four groups of pigeon were vaccinated with PPV; group (1) vaccinated via feather follicle route in addition to other 3 groups of pigeon ( group 5, 6 and 7) vaccinated via aerosol route with different Gel 01 adjuvant ( 5%, 10% and 15% respectively ). Serum samples were collected weekly for 6 weeks. The highest level of induced antibodies detected by virus neutralization test (VNT) and ELISA were (3.0, 2.0, 2.5 and 2.5 NI respectively) and ( 1.9, 1.5, 1.8 and 1.7 S/P respectively) at the 3 rd week post vaccination. The level of antibodies reduced dramatically in pigeon groups vaccinated via aerosol route group (5, 6 and 7) reached (1.5, 1.75 and 2.0 NI respectively ) and (1.2 , 1.3 and 1.4 S/P respectively ) at 6 th week on contrast to group (1) vaccinated with feather follicle route has a slight decrease in antibody level reached 2.75 NI and 1.8 S/P at the 6 th week post vaccination. Negative result for VNT and ELISA were found in control non vaccinated group all over the period of study. All vaccinated four pigeon groups and non vaccinated control group were challenged by inoculation of the virulent PPV after 3 weeks from vaccination showing protection percent of 95%, in group (1) vaccinated by feather follicle while it was 85%, 90%and 90% in groups vaccinated via aerosol route with different Gel 01 percent ( 5%, 10% and 15% respectively ) showing that 10 % Gel 01 is the concentration of choice to be used with PPV via aerosol route. On contrast, the control non- vaccinated pigeons showed 0% of protection. This study recorded the efficacy of aerosol vaccination of tissue culture adjuvanted PPV in pigeon using Gel 01 comparison to usual routine vaccination with unadjuvanted PPV by feather follicle route to establish a more safe route of vaccination in valuable oriental and racing pigeons and easier route of vaccination of large pigeon flock with recommendation of booster vaccination after 3 weeks in order to maintain a high level of protection and more duration of immunity.