Neonatal and Infantile Immune Responses to Encapsulated Bacteria and Conjugate Vaccines
Figure 1
Schematic diagram of mechanism of action of PS and PS-protein conjugate vaccines.
(a) Polysaccharide vaccines stimulate marginal zone B-cells which will proliferate in loco and differentiate into short-living plasma cells, which are responsible for the rapid release of low-affinity antibodies and thus first-line defence against the pathogen; (b) conjugate vaccines stimulate B-blasts that will migrate into the germinal centre, where they proliferate, undergo somatic hypermutations and isotype class switch, and differentiate into either long-living plasma cells (that produce high-affinity antibodies) and memory B cells. Abbreviations: CD40L (CD40 ligand), GC (germinal centre), MZ (marginal zone), DC (dendritic cell), MZ DC (marginal zone dendritic cell).
