Patent ID: 7144712

Claim:
A method of making a modified hepadnavirus core antigen comprising: providing a first nucleic acid encoding a heterologous antigen, wherein said heterologous antigen is 50 or fewer amino acids in length and has an isoelectric point greater than or equal to 7.0; providing a second nucleic acid encoding a hepadnavirus core antigen, wherein said hepadnavirus core antigen is selected from the group consisting of a woodchuck hepadnavirus core antigen, a ground squirrel hepadnavirus core antigen and a human hepadnavirus core antigen; altering nucleotides of said first nucleic acid to reduce said isoelectric point of said heterologous antigen below 7.0; combining said first and second nucleic acids, wherein said combining comprises placing said first and second nucleic acids in operable combination such that said heterologous antigen is expressable within an immunodominant loop or within an alpha-helix adjacent to said immunodominant loop; and expressing said first and second nucleic acids to produce a modified hepadnavirus core antigen comprising the amino acids encoded by said first and second nucleic acids.