Final answer:
Prevnar 13, a pneumococcal conjugate vaccine, contains pneumococcal polysaccharides linked to a carrier protein to induce a strong T-cell dependent immune response, generating lasting immunity, especially in young children.
Step-by-step explanation:
Understanding Pneumococcal Conjugate Vaccines
Prevnar 13 is an example of a pneumococcal conjugate vaccine. This type of vaccine is designed to provoke an enhanced immune response in individuals, especially young children who have a poor response to polysaccharide antigens on their own. The vaccine is made by conjugating, or linking, polysaccharide molecules from the pneumococcus bacteria's capsule to a carrier protein. This permits the immune system to mount a T-cell dependent response, which is generally more robust than the response to plain polysaccharide vaccines.
When pneumococcal polysaccharides are conjugated to a carrier protein, the resulting vaccine can initiate a T-cell dependent immune response, which is essential for memory and longevity of the immune response. This process also leads to the production of antibodies that can recognize and respond to the pneumococcus bacteria more effectively. The conjugation enables the immune system to recognize the vaccine as if it were a natural infection, thus providing a greater degree of protection.