VACCINATION AND MUCOSAL RESPONSES TO HELICOBACTER-PYLORI INFECTION

H. pylori infection persists for life if not treated, and is responsib le for major morbidity and mortality throughout the world. Preventativ e immunization, once thought to be impossible, is now considered by ma ny to be the only practical approach to large-scale elimination of the bacterium from susceptible populations. High rates of protection have been achieved in the H. felis mouse model, utilizing antigens ranging from whole cells to purified recombinant proteins selected on the bas is of their role in pathogenicity, Immunization has also been shown to cure established infection. H. pylori mouse models have been develope d and may become the model of choice. Urease remains the favourite ant igen but combinations will most likely be required. A priority is to d efine alternate muscosal adjuvants, as some used in the animal models may be too toxic for use in humans. Also, there is a need to understan d the basis of immunization. Why does the natural immune response to H . pylori fail while the artificially stimulated response succeeds? The fist important steps towards a vaccine have been made but, given safe ty issues and regulatory requirements, it may be 5-8 years before the final product becomes available. Over these years antimicrobial resist ance is likely to be an increasing problem in the treatment of H. pylo ri infections. Thus, when the vaccine comes, the time will be ripe for the completely new approach of therapeutic immunization.