A B S T R A C TThis work aimed to study quail susceptibility to Newcastle disease virus (NDV); their role in disease transmission and their immune response to ND vaccine. Forty percent (4/10) of quail were susceptible to experimental infection with virulent NDV with signs of loss of appetite, weakness, diarrhea and nervous symptoms then death. Chickens group housed in contact with infected quail and chickens group experimentally infected with NDV were suffering from typical NDV infection 15 days post contact infection and 3 days post experimental infection, respectively. Post mortem examination of dead birds revealed hemorrhagic lesions of the intestinal tracts and proventriculus; and NDV was recovered from tracheal and intestinal samples and identified by HI test using NDV-Specific antiserum. Birds vaccinated with inactivated NDV vaccine exhibited detectable antibody titers (2 log2) by the 1st week post vaccination (WPV) to reach their peaks by the 3rd WPV (6 log2 in quails and 7 log2 in chickens). These antibody titers were able to protect quail and chickens against challenge with virulent NDV recording 100% protection rates in comparison to non-vaccinated birds showing 70% and 100% mortality in quails and chickens, respectively. Being susceptible for NDV, quail have a role in transmission of NDV to chickens, so they should be vaccinated for their protection and prevent their role in NDV transmission to chickens.

The goal of the presented work was to prepare and evaluate physical characters and immunogenicity of a combined inactivated Avian Influenza Virus (AIV) H5N1, H9N2 subtypes and Infectious Bronchitis Virus (IBV), strain D-88 oil emulsion vaccines. The prepared vaccines were sterile and safe. Also, they were ensured to be water in oil (W/O) emulsions using drop test, conductivity (zero mS/cm). Particle size were 950 nm and 1050 nm and dynamic viscosities were 19.52 Mpa.s and 39.65 Mpa.s for the vaccine with Montanide™ ISA 71 RVG adjuvant and the vaccine with paraffin oil adjuvant, respectively. They showed stability for 24 months at 4 °C with no separation. Combined inactivated oil emulsion vaccines induced cellular and humoral immune responses in vaccinated chicks. The vaccine with Montanide™ ISA 71-RVG adjuvant provided 100% protection percent for AIV H5N1 without shedding of AIV H9N2 and IBV in comparison to the combined vaccine with paraffin oil adjuvant that gave 84% protection percent for AIV H5N1 and shedding of AIV H9N2 and IBV occurred 6 th day post challenge. Montanide™ 71-RVG adjuvant has the flexible ratio of oil and antigenic media in the vaccine (60:40) allowed using large amount of virus that showed good impact on its immunogenicity, over the paraffin oil adjuvant which has restricted ratio of oil and antigenic media of the vaccine (73:27).

Bovine ephemeral fever (BEF) is an infectious, arthropod-born viral disease has economic importance in cattle and buffaloes. Vaccination is widely used to control and prevent BEF disease. This study aimed to prepare an inactivated BEF vaccine using Montanide ISA 206 (water-in-oil-in-water) adjuvant that was applied in two different protocols (one dose and two doses one month apart). The prepared vaccine was sterile and safe. It was found that a single dose of the vaccine induced protective neutralizing serum antibody titer from 2nd week post vaccination (PV), reached highest titer at 10th week PV and persisted in this protective titer until 34 weeks PV using SNT and confirmed using ELISA, however boostering of animals 4 weeks post preliminary vaccination increased the titer of the protective neutralizing antibodies and its time duration to 44 weeks PV. Thus, in order to provide immunity that will last the entire season it is recommended that the vaccine should be administered short time before the onset of BEF season (summer season).

Rift Valley Fever (RVF) virus belonged to genus Phlebovirus, family Bunyaviridae cause an acute, febrile disease in ruminants. In Egypt, a locally prepared inactivated RVF virus vaccine with aluminum hydroxide gel adjuvant has long been used for immunization of susceptible animals against the disease. The choice of an adjuvant which gives high and long standing immune response assume a critical part in immunization. The present study aimed to develop a new RVF virus vaccine with Montanide oil IMS 1313 nanoparticles as adjuvant and evaluate its impact on cellular and humeral immune response in sheep. The prepared vaccine was sterile and safe. SNT results demonstrated that the prepared vaccine induced protective neutralizing serum antibody titer from the 2 nd week post vaccination (PV), reached the highest level at the 3 rd month PV and persisted in protective level until the 9 th month PV. These results were confirmed using ELISA. Evaluation of RVF virus-specific cell-mediated immunity in vaccinated sheep using XTT assay showed significant lymphocyte proliferation expressed by optical density in vaccinated sheep group that increased to reach a maximum 10 th day PV. Results indicated that the Montanide IMS 1313 VG NPR oil based vaccine induced high immunological enhancement without toxicity and with long duration of immunity that extended for 9 months.

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