BNP peptide/KLH is an antigen-adjuvant conjugate consisting of BNP peptide (human brain natriuretic peptide) and keyhole limpet hemocyanin (KLH). This conjugation enhances the production of antigen-specific antibodies in vaccine models by linking the antigen with the protein adjuvant. The conjugate does not affect protein folding or disrupt key epitopes, while also boosting cross-presentation and the generation of antigen-specific T cells.