Helicobacter pylori vaccine development: facing the challenge.

An effective vaccine would be a desirable way to control Helicobacter pylori-induced gastric disease. Initial studies in animal models demonstrated the feasibility of immunization and led to high hopes for a human vaccine. In the mouse model immunological approaches have to date not brought a satisfactory explanation for the mechanisms of protection against this largely luminal pathogen. Recently, transcriptome studies have identified new factors. It is now proposed that non-classical immune mediators may be the key to vaccine-induced protection. Human trials of H. pylori vaccines are going ahead but although at least some formulations are clearly immunogenic, their effectiveness remains untested. The recent development of a human challenge model has now opened up new prospects for testing candidate vaccines and this will undoubtedly have a great impact in the near future. Future priorities for H. pylori vaccine development must be a better understanding of the protective mechanisms and the identification of biomarkers which can be used as reliable predictors of efficacy in humans. Despite some important advances in recent years, important issues must be resolved before an H. pylori vaccine will become a reality.