The key to conjugate vaccines lies in their ability to stimulate a stronger immune response. Polysaccharides alone often fail to produce a robust immune memory, especially in young children. By attaching these polysaccharides to a protein, the immune system recognizes the combination as a more complex antigen, prompting a stronger and longer-lasting immune response. The protein carrier acts as an immunogenic component that boosts the body's ability to produce antibodies against the polysaccharide.