Protective efficacy of live Salmonella gallinarum 9R vaccine in commercial layer flocks

Salmonella enterica serovar Gallinarum (S. Gallinarum) is the causative agent of fowl typhoid, a severe systemic disease of chickens that results in high mortality. In this study we re-evaluated the ability of live S. Gallinarum 9R vaccine to protect from wild-type S. Gallinarum challenge. In laboratory trials, there was a significant difference between the vaccinated and unvaccinated control groups in mortality and the reisolation rate of the challenge strain from the tissues (P