Chronic typhoid bacteriuria is an unsolved problem in infectious diseases. History knows that one chronic typhoid bacteriocarrier, working in a dairy factory in 19th century Germany, was the source of the pathogen for more than 5000 people. Many vaccines and other immunobiological preparations have been developed to deal with typhoid fever. Existing vaccines affect the third part of the epidemic process and are aimed at creating immunity to the disease, although they do not have 100% immunogenicity and have no therapeutic effect on the chronic bacteriophage. In Uzbekistan, we have developed a dual-purpose peritoneal molecular vaccine (PMV) for both prophylactic immunization and treatment (sanation) of chronic bacteriuria. Therefore, this publication will deal with the principles of selection and the possibility of selecting strains with different biological properties for the production of a new generation of highly immunogenic therapeutic and prophylactic vaccine against typhoidfever.