Group B Streptococcus capsular polysaccharide serotype IV (GBS CPS IV)

Group B Streptococcus (GBS) capsular polysaccharide serotype IV is a complex carbohydrate structure located on the surface of Streptococcus agalactiae serotype IV. It serves as a critical virulence factor by providing a protective barrier that inhibits the host's immune system, specifically by preventing complement-mediated opsonophagocytosis through its terminal sialic acid residues [8, 14]. Serotype IV has emerged as an increasingly prevalent cause of invasive GBS disease, including neonatal sepsis, meningitis, and pneumonia, as well as infections in immunocompromised adults [22, 25]. As a therapeutic target, it is a primary component of multivalent glycoconjugate vaccines, such as Pfizer's hexavalent GBS6 (PF-06760805), which is currently in late-stage clinical development [9, 13]. These vaccines work by inducing serotype-specific IgG antibodies in pregnant women, which are then transplacentally transferred to the fetus to provide passive immunity to the newborn [11, 16]. The development of such vaccines aims to reduce the global burden of GBS-related neonatal mortality and morbidity, particularly in regions where intrapartum antibiotic prophylaxis is difficult to implement [12, 21].

Other names

GBS serotype IV capsular polysaccharideType IV GBS polysaccharideStreptococcus agalactiae serotype IV capsular polysaccharideGBS CPS4Group B Streptococcus type IV antigen

Induction of protective opsonophagocytic antibodies (IgG) that facilitate bacterial clearance by the immune system.