Fc fusion proteins for enhancing the immunogenicity of protein and peptide antigens

A composition for eliciting an immune response against an antigen in a mammal, the composition comprising:

• an adjuvant;
• and
• an antigen fusion protein comprising an antigen linked by a polypeptide bond to an immunoglobulin heavy chain constant region whose ability to bind an Fc receptor is not modified by mutation, wherein the antigen fusion protein lacks an immunoglobulin variable domain and the antigen of the fusion protein is capable of eliciting a stronger immune response in the mammal than the antigen alone, wherein the antigen is selected from the group consisting of Prostate-Specific Membrane Antigen, an ectodomain of a cytokine receptor, a viral protein and a tumor-specific protein, the composition being formulated for intramuscular, intravenous, transdermal or subcutaneous administration.