Oxytetracycline/OVA is an antigen-adjuvant conjugate composed of Oxytetracycline and ovalbumin (OVA). This conjugation boosts the production of antigen-specific antibodies in vaccine models by linking the antigen with the protein adjuvant. The conjugate does not alter protein folding or disrupt primary epitopes, while it enhances cross-presentation and the generation of antigen-specific T cells.