Abstract: A live Salmonella vaccine having an increased stability is disclosed. Further, immunization methods of a host such as chickens against Salmonella diseases are carried out by the use of the vaccine. The vaccine may be administered orally or parenterally and includes one or more of the live vaccines disclosed herein. The live vaccine is produced from one or more live vaccine strains with metabolic drift attenuation via an increased generation time. The vaccine is an immunogenic, stable and single or multiple marker live vaccine strain with or without envelope mutation; and the live vaccine is a suppressor mutant of an original live vaccine strain still having the attenuation marker(s) of the original live vaccine strain but a shortened generation time and having macrolide tolerance.