Safety and immunogenicity of an intranasal vaccine against pneumonic mannheimiosis of sheep and goats following field vaccination.

Background: Pneumonic mannheimiosis is an important respiratory disease that inhibits production in sheep and goats. It is associated with stress, resulting in 10% to 40% mortality. The disease should be effectively controlled. Aim: This field vaccination trial evaluates the safety and immunity of a newly manufactured vaccine (STVac7 Methods: A sheep and a goat breeder farm were identified, before 2 groups of breeder sheep with 80 animals per group, and 2 groups of breeder goats with 50 animals per group were selected. Group 1 sheep and goats were vaccinated intranasally, while Group 2 remained unvaccinated. Vaccinations were conducted on weeks 0 and 2. Throughout the 24-week (sheep) and 12-week (goats) study periods, animal management in both farms remained unchanged. Serum samples were collected from both groups before and at weekly intervals after vaccination, while nasal swabs were collected at monthly intervals. Adverse effects, including sneezing, coughing, nasal discharge, and mortality, were noted weekly throughout the study period. Results: Intranasal vaccination did not cause significant side effects in sheep and goats, although mild nasal discharge and coughing were occasionally observed. Only one non-vaccinated ewe (1.3%; Conclusion: Intranasal vaccination of sheep and goats with STVac7