Immunity to Salmonella infections.

The results of current investigations regarding the mechanisms of immunity to Salmonella infections and the use of vaccines are presented. Since chemical suppression of the humoral immune response in chickens does not jeopardise immunization with a live vaccine and immunized guinea-pigs exhibit distinct inhibition of macrophage migration, it is concluded that cellular immunity is a prominent factor in protection. Data is presented to show that the mice and calves can be equally well immunized with either live or inactivated S. typhimurium and S. dublin vaccines and the practical advantages of inactivated vaccines are discussed.