VACCINE COMPOSITIONS

摘要

Novel DNA constructs are provided that are capable of transforming microorganisms such that they can be used as live or attenuated vaccines which induce such immune response at mucosal surfaces. Further provided are such transformed microorganisms per se and vaccine compositions containing them. Preferred constructs of the invention are capable of transforming microorganisms such that they express Y. pestis protein or a protective epitopic fragment thereof while retaining a capability to establish themselves in human or animal gut environment. Several constructs have been identified that are capable of transforming gut dwelling organisms such as S. typhimurium or S. typhi to enable V-protein antigen production.