Infant B cell responses to polysaccharide determinants

Vaccine. Aug-Sep 1998;16(14-15):1396-400. doi: 10.1016/s0264-410x(98)00098-x.


Newborns and infants up to the age of 1.5-2 years of age are unable to produce antibodies to bacterial capsular polysaccharides. As a consequence, children up to the age of 2 years have an increased susceptibility for infections with encapsulated bacteria. Capsular polysaccharides are classified as so-called T cell independent type 2 antigens and induce IgG2 antibodies. The mechanism of B lymphocyte activation by polysaccharides differs from that of protein antigens and involves co-stimulation by CD21 (type 2 complement receptor). Reduced expression of CD21 on neonatal B lymphocytes can explain unresponsiveness to polysaccharides. Polysaccharide protein conjugates have the ability to overcome unresponsiveness to polysaccharides early in life. The response induced is predominant IgGl.

Publication types

  • Review

MeSH terms

  • B-Lymphocytes / drug effects
  • B-Lymphocytes / immunology*
  • Child, Preschool
  • Epitopes / immunology*
  • Epitopes / pharmacology
  • Humans
  • Infant
  • Infant, Newborn
  • Lymphocyte Activation / drug effects
  • Lymphocyte Activation / immunology*
  • Polysaccharides, Bacterial / immunology*
  • Polysaccharides, Bacterial / pharmacology


  • Epitopes
  • Polysaccharides, Bacterial