VACCINE FOR PREVENTION OF GASTROENTERIC DISEASE:NON-PATHOGENIC STRAIN GENETICALLY ENGINEERED TO COMPRISE GENES FOR ADHESIN AND/OR TOXOIDS

摘要

A vaccine is described for prevention of gastroenteric disease caused in a mammalian species by a pathogenic microorganism and which avoids, in its manufacture, the use of pathogens (which must be attenuated or killed) and the attendant risks, costs and complexity. The present vaccine comprises a nonpathogenic microorganism strain containing stable replicative plasmids, each having one or more genes non-indigenous to the plasmid. The non-indigenous genes are either genes for an adhesin necessay for adherence of the pathogenic microorganism in the mammalian species or are genes for toxoids of toxins causative of the disease. Both types of genes may also be included in the same plasmid. The invention includes the method of manufacture of such vaccines and their use in stimulating the production of antibodies.