Table 3.

Number of aP vaccine recipients showing positive Ab responses according to CMI status

CMI statusaB. pertussisantigenNo. of subjects testedSeropositivity (%)b
ConvertersPT131 (7.6)
PRN159 (60)
FHA97 (77.7)
NonconvertersPT151 (6.6)
PRN82 (25)
FHA135 (38)
  • a At 48 months of age; all negative at 7 months of age.

  • b To the B. pertussis antigen showing CMI conversion or nonconversion. Seropositivity was defined as a value of ELISA units four times higher than the MLD, set at 2 U/ml for IgG to PT and FHA and 3 U/ml for IgG to PRN.