A method of identification and elimination of immunodominant epitopes to elicit a response to secondary epitopes, especially conserved structures, is described, and applied to influenza haemagglutinin (HA). Identification of the primary epitopes in (HA), and replacement of amino acids having high LODrps with corresponding low LODrps amino acids produces an HA molecule which induces antibody responses to conserved HA residues. Modified HA molecules induce a broadly neutralizing vaccine.