Adaptive immune system (via Pneumococcal capsular polysaccharide–CRM197 conjugates)

The adaptive immune system is the primary biological target for pneumococcal conjugate vaccines (PCVs), which aim to provide long-term protection against Streptococcus pneumoniae infections (CDC, 2022). These vaccines utilize pneumococcal capsular polysaccharides, which are typically T-cell independent antigens, and chemically conjugate them to CRM197, a non-toxic mutant of the diphtheria toxin (NIH PubChem, 2023). This conjugation is essential because polysaccharides alone do not elicit a strong immune response in infants or provide long-lasting memory (StatPearls, 2023). By linking the polysaccharide to the CRM197 carrier protein, the vaccine recruits T-helper cells, transforming the immune response into a T-cell dependent process (PubMed, 2013). This leads to the production of high-affinity IgG antibodies and the establishment of B-cell memory, which are critical for preventing invasive diseases such as pneumonia, meningitis, and sepsis (WHO, 2021). Drugs interacting with this system include major conjugate vaccines like Prevnar 13 and Prevnar 20, which target a broad range of pathogenic serotypes (FDA, 2021).

Other names

Pneumococcal conjugate vaccine mechanismPCV-CRM197 mediated immunityAdaptive immune system via pneumococcal capsular polysaccharide–CRM197 conjugatesCRM197-polysaccharide conjugate

The vaccine conjugates T-cell independent pneumococcal capsular polysaccharides to a CRM197 carrier protein, which recruits T-helper cells to induce a T-cell dependent immune response, resulting in high-affinity antibodies and immunological memory.