Helicobacter based preparations comprising a pharmacologically active molecule of interest are disclosed, as well as methods of preparing and using said preparations. In particular, Helicobacter pylori vectors, vector plasmids and recombinant cells that include a sequence encoding a pharmacologically active molecule of interest useful in therapeutic treatments and/or vaccination against disease are provided. Delivery of the pharmacologically active molecules is provided at the mucosal surface, such as the gastric mucosa or nasal membranes, to provide effective and continuous delivery of a pharmacologically active agent. Vectors and shuttle vector constructs are also provided
