4,4'-Sulfonyldiphenol/BSA is an antigen-adjuvant conjugate composed of 4,4'-Sulfonyldiphenol bound to bovine serum albumin (BSA). This conjugation enhances the generation of antigen-specific antibodies in vaccine models by linking the antigen to the protein adjuvant. The conjugate maintains protein folding and preserves primary epitopes, while improving cross-presentation and the production of antigen-specific T cells.