Lack of protection following immunisation with H. pylori outer membrane vesicles highlights antigenic differences between H. felis and H. pylori.

Helicobacter pylori-induced inflammation is associated with the development of gastritis, peptic ulcer disease and gastric cancer in humans. Immunisation against this bacterium would ultimately have a major impact on H. pylori-related disease, notably global gastric cancer rates. To date, several potential H. pylori vaccine candidates have been identified. In this study, the Helicobacter felis/murine model was used to assess the immunogenicity of a previously undescribed H. pylori outer membrane vesicle fraction in immune protection.