Table 1.

Losses and gainsa of CMI responses to B. pertussis antigens in 48-month-old pertussis vaccine recipients

AntigenLoss of CMI+(%)Gain of CMI+ (%)
aP-CBaP-SBaP-CBaP-SB
PT332065.255.5
PRN28225069.2
FHA3037.554.436.4
  • a Calculated with respect to the proliferative PBMC responses of the same subjects at 7 months of age. CMI was defined as positive (CMI+) when the difference between the lymphoproliferative response (measured as [3H]thymidine incorporation and expressed in counts per minute) of the antigen-stimulated PBMC culture and that of the unstimulated control culture was ≥3,000 (corresponding to a stimulation index of ≥4).