The efficiency of vaccination against cattle necrobacteriosis using an experimental vaccine with a new adjuvant complex

Abstract

The purpose of the study was to analyze the effectiveness of the adjuvant complex based on saponin, glycerin and chitosan in the experimental series of an inactivated vaccine against cattle necrobacteriosis. 4 groups of animals (30 in each group) were selected for the study, aged 6 to 24 months. The first (1st) group consisted of calves 6 months old, the second (2nd) group consisted of animals 12 months old and the third group – animals 24 months old. The control 4 (fourth) group (non-vaccinated animals) contained 10 animals of each age group – 6, 12 and 24 months old. The animals were vaccinated using a needle-free injector at a dose of 0.4 cm³ in two points at a distance of 7–10 cm (0.2 cm³ each) twice at intervals of 4-6 weeks.  Revaccinated after  6 months, with a single dose of 0.4 cm3 (at two points, 0.2 cm² each). It was found that the vaccine with the multicomponent adjuvant had low viscosity and hardening temperature, moderate reactivity, high stability during storage, prolonged immunity in vaccinated animals. The immunity in animals was detected 21 days after the first vaccine administration and lasted at least 18 months after the last immunization. The necrobacteriosis incidence in animals of the control non-vaccinated group was 70-80%. During double vaccination, the average level of postvaccinal agglutinating antibodies in serum of experimental groups of animals was 312.08 ± 74.12 – 62.13 ± 69, 07. Humoral response in vaccinated animals provided reliable protection against Fusobacterium necrophorum disease within two years (observation period). Absence of disease symptoms in vaccinated animals during 2 years testified to the high preventive efficiency of the vaccine. The results obtained confirm the validity of the application of multicomponent adjuvant in inactivated sorbed vaccine as a means of specific prevention of animal necrobacteriosis.