[An oral enteritis-vaccine composed of twelve heat inactivated Enterobacteriaceae. 1. Communication: Theoretical and epidemiological considerations (author's transl)].

The infectious diseases of the human intestinal tract which are caused by bacteria must be distinguished into two groups on account of their different pathogenesis: the cyclic infections (typhoid fever, parathyphoid fever) and the local infections (cholera, dysentery, Salmonella enteritis, dyspepsia coli infections). The local infections of the intestine do not cause a systemic but only a local immunity of the intestinal mucosa. It is necessary therefore to induce local immunity as active immunoprophylaxis by orally administering inactivated antigens. The twelve-fold enteritis vaccine consists of full antigens of 6 Salmonella strains, 2 Shigella strains, and 4 enteropathogenic coli strains pretreated by heat-inactivation (3 min/100 degrees C). The following should be considered as indication to effect active immunoprophylaxis against enteritis: Travelling into tropical and subtropical countries, people in emergency areas, children in developing countries, workers in food industries, secondary hospital infections, and carriers. The active mouse protection test revealed that oral immunization with enterobacteriaceae does not only deliver the well-known specific effect but also a non-specific effect which included the protection against other related enterobacteriaceae. Moreover, the specific component of the combined vaccine is enhanced by heterologous components. The resulting synergism or the adjuvantal effect, respectively, allows to employ a relatively limited number of germs which are selected on the basis of high pathogenicity, good immunogenicity, and great frequency. The first field trial with the twelve-fold vaccine was completed successfully: Following an infection with Salmonella which affected the employees of a fowl slaughtery, eight different species could be demonstrated; the above described polyvalent vaccine was orally administered and proved to be successful. The latter case clearly demonstrates the fast-acting effect of the vaccine on account of the heterologous bacterial antigens contained therein. 51 out of 60 Salmonella carriers excreted germs of a different antigen pattern not contained in the vaccine. However, the good results obtained showed that the species chosen for the vaccine were still sufficiently effective to cover the wide spectrum of other species of related enterobacteriaceae.