Figure 4.
Numbers of memory B-cells in children 9 years of age before and after a Tdap booster vaccination. The numbers of (A) pertussis toxin (PT), (B) filamentous hemagglutinin (FHA), (C) pertactin (Prn), and (D) tetanus toxoid-specific IgG producing memory B-cells per 105 IgG producing B-cells of whole-cell pertussis (wP)- (blue circles) or acellular pertussis (aP)-primed (red triangles) children 9 years of age before, 1 month, and 1 year after a preadolescent Tdap booster vaccination. Note, black lines indicate geometric mean numbers, *p-value <0.05, and **p-value <0.01. For all antigens, values of pre versus 1 month, pre versus 1 year, and 1 month versus 1 year were all significantly different within the wP- and aP-primed longitudinal groups of children (all p-values <0.05). Note, data of wP-primed children were previously published (26).