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 pharamacologically 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. In some embodiments, the Helicobacter provides exposure of a desired molecule of interest though the surface of the Helicobacter, providing exposure of the antigen to the host at the gastric mucosa. Live Helicobacter pylori vaccines are also provided. Vectors and shuttle vector constructs of the Helicobacter are also disclosed.