Vaccines containing bacteria attenuated by mutations in two genes of the aromatic amino acid biosynthetic pathway

摘要

An attenuated microorganism harboring two mutated genes, each of which is located in the organisms aromatic pathway is provided. These organisms can usefully form the basis of a vaccine. They can be genetically engineered so as to express antigens from other pathogens and thus form the basis of a range of multi-valent vaccines.