Evaluation of bivalent Salmonella inactivated vaccine on shedding of O4 serogroup Salmonella

An oil-adjuvanted vaccine for Salmonella Enteritidis(SE)and Salmonella Typhimurium(ST) was developed. This vaccine decreases the shedding rate of SE or ST in cecal droppings. This report confirmed that the vaccine decreased the shedding rate on Salmonella Heidelberg (SH), Salmonella Saintpaul (SS), and Salmonella Agona (SA) that is the same O4 Serogroup Salmonella as ST. The oil-adjuvanted vaccine was inoculated subcutaneously (0.5 mL) into the back of the neck of chickens. Four weeks after the vaccination, the vaccinated and unvaccinated chickens were challenged by oral administration with SH. The number of SH from cecal droppings of the vaccinated chickens was significantly lower than that in the unvaccinated chickens at 4, 7, 10 and 14 days post-challenge (PC). The number of SH from cecum of the vaccinated chickens was significantly lower than that in the unvaccinated chickens at 14 days PC. In addition, a similar result was obtained with the SS and the SA challenges, demonstrating that this vaccine decreased the shedding rate for O4 Serogroup Salmonella (SH, SS, SA).