Pneumococcal polysaccharide-protein conjugate antigen (PCV)

Pneumococcal polysaccharide-protein conjugate antigens are the primary immunogenic components of pneumococcal conjugate vaccines (PCVs), designed to protect against infections caused by Streptococcus pneumoniae [1]. These antigens consist of capsular polysaccharides from specific bacterial serotypes that are chemically linked to a carrier protein, such as CRM197 (a non-toxic diphtheria toxin mutant), tetanus toxoid, or Haemophilus influenzae protein D [2]. This conjugation is critical because bacterial polysaccharides alone are T-cell independent antigens that do not elicit a robust immune response or memory in children under two years of age [4]. By coupling the polysaccharide to a protein carrier, the vaccine induces a T-cell dependent response, leading to the production of high-affinity IgG antibodies and the establishment of long-term immunological memory [2, 3]. These vaccines are highly effective in preventing invasive pneumococcal diseases, including meningitis, bacteremia, and pneumonia, as well as mucosal infections like otitis media [1, 4].

Other names

Pneumococcal conjugate vaccinePCVPCV7PCV10PCV13PCV15PCV20PCV21PCV24Streptococcus pneumoniae capsular polysaccharide conjugate

Induction of T-cell dependent immune response against Streptococcus pneumoniae capsular polysaccharides through conjugation with a carrier protein, facilitating B-cell maturation and memory [2, 4].