Introduction. Chicken cholera is one of the most dangerous avian infectious diseases, causing significant economic damage to the industrial poultry production. Chicken cholera usually occurs in septic form, and causes high morbidity and mortality (60–80%), but recently it has become chronic, subclinical and associated. Inactivated emulsion vaccines are used worldwide to prevent chicken cholera and provide high and long-term immunity. However, there is a problem with residual reactogenicity of inactivated vaccines, particularly of the bacterial variants. This problem can be solved by using safer, next-generation adjuvants. The aim of the article is to study the physical and biological properties and determine the optimal inoculation volume and method of administration of inactivated vaccines against chicken cholera , based on different adjuvants.Materials and methods. Formaldehyde inactivated culture of P. multocida st. 115and a number of adjuvants (“Montanide GEL-02” and oil adjuvants “Montanide ISA 70 VG” and “Montanide ISA 78 VG”) were used for vaccine production. The vaccine samples were tested for sterility, stability and viscosity by conventional methods. Determination of reactogenicity and antigenic activity of the vaccines was carried out on young 30-days old chickensof egg-laying type.Results. The vaccine sample based on the adjuvant “Montanide ISA 70 VG” containing 1.5 billion P. Multocida microbial cells in a single immunizing dose of 0.3 cm3 was found to be the best among the tested preparations. When assessing the reactogenicity, it was obvious that all samples, regardless of the type of adjuvant, showed more pronounced residual reactogenic properties when injected intramuscularly into the chest muscle than when injected subcutaneously into the middle third of the neck.
Avibacterium paragallinarum causes a severe respiratory disease characterized by catarrhal inflammation of the mucous membranes of the nasal cavity, infraorbital sinuses, and conjunctivitis. The study aims to determine the reactogenicity and protective properties of inactivated vaccines against Av. paragallinarum is made using mineral‐salt adjuvant aluminum hydroxide (AH) and high molecular weight acrylic acid‐carbomer polymer. Vaccine samples were made of inactivated Av. paragallinarum cultures of strains B‐7770 (serotype “A”), “1130917 / AmsB” (serotype “B”), and 150215 / TulaC2 (serotype “C”). A milliliter of each vaccine contained 1.0 billion microbial cells of each Av. paragallinarum serotype. The first sample contained AH adjuvant, and 2nd sample had a carbomer in it. Vaccines were tested on 60 days old layer hens. Ten birds were immunized with each vaccine sample to determine reactogenicity. The vaccine was injected intramuscularly between the radius and ulna in a volume of 2.0 cm3. Ten days after immunization, the birds were euthanized and autopsied to measure the local tissue response at the region of vaccine administration. Three groups of chickens (n=10) were formed to measure the immunogenic activity. Birds of the first and second groups were intramuscularly inoculated with one vaccine sample in a volume of 1.0 cm3. The chickens of the 3rd group were not vaccinated. After 28 days of research, all chickens were infected with a mixture of Av. paragallinarum “A,” “B,” and “C” serotypes. The culture mixture was applied intraocularly at 10 50% infectious doses for each serotype. All birds vaccinated with the AH and carbomer vaccines had swelling of soft tissues and petechial hemorrhagic lesions of the muscles near the inoculation area. Fibrin plates (0.2x1.5 cm) were found in the muscles of the inoculation area in 5 AH cases. No clinical manifestation of the disease was found in both vaccinated groups, which indicates good protective properties of the tested vaccine samples. All 10 chickens of the 3rd group showed symptoms of a respiratory disease after infection with Av. paragallinarum, which reveals a high susceptibility of unvaccinated hens to the bacteria. Inactivated vaccine against Av. paragallinarum with carbomer as an adjuvant is less reactogenic than a similar vaccine made using AH. At the same time, both vaccine samples have good protective properties.
The article describes the characteristics of Newcastle disease, highlights the etiology, epizootology and specific methods of control of this disease in industrial poultry farming. The fundamental aspects of the use of spe- cific prevention agents are described and the effective scheme of live and inactivated vaccines against Newcastle dis- ease in monovalent and associated variants is presented.
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