DEVELOPMENT OF A VACCINE AGAINST HELICOBACTER-PYLORI - A SHORT OVERVIEW

Aim: Growing evidence that gastric and duodenal disease is caused by Helicobacter pylori infection suggests that this disease may be prevented by vaccination. We therefore assessed the possibilities for development of a vaccine. Method: Survey of published studies. Present state of development: Development of a vaccine requires identification of the factors responsible for bacterial virulence and disease induction and large-scale production and testing of potential vaccines in animal models. So far several factors involved in bacterial adhesion, colonization and virulence have been identified. Among these, the most promising candidates for vaccine development are the adhesins, the vacuolating cytotoxin and urease. Urease-based vaccines have shown some promising results in protecting mice against H. felis infection. Proposals: The unique features of H. pylori infection and disease formation in man suggest that vaccines should be tested in models more relevant to humans, and that the vacuolating cytotoxin and the cytotoxin-associated gene A (cagA) should be seriously considered as vaccine candidates. This hypothesis is supported by the recent observation that only the subset of strains that produce the vacuolating cytotoxin and cagA are associated with disease.