The present invention is drawn to attenuated Salmonella serovar strains S. Typhimurium and S. Enteritidis, conjugate vaccines derived from these attenuated strains of S. Typhimurium and S. Enteritidis, comprising an O polysaccharide covalently linked to a flagellin protein, and methods for inducing an immune response in a subject comprising administering the attenuated strains and/or the conjugate vaccines of the invention.