Abstract: The subject invention provides a fusion protein for producing a dual immune response in a vertebrate, which fusion protein comprises: (a) a first proteinaceous portion analogous to all or part of a peptide endogenously synthesized within the vertebrate, the activity of which peptide is to be inhibited within the vertebrate, and which proteinaceous portion by itself is incapable of eliciting an effective immunoinhibitory response in said vertebrate; connected to (b) a second proteinaceous portion analogous to all or part of an immunogen from a pathogen, which pathogen is capable of pathogenically infecting the vertebrate; the portion (b) causing the vertebrate's immune system to recognize the portion (a) and produce a response that: (i) inhibits the activity of the peptide endogenously synthesized within the vertebrate; and (ii) protects the vertebrate from infection by the pathogen, when the vertebrate is vaccinated with an effective amount of the fusion protein.