The immune seroresponse to routine concomitant vaccination was measured as the percentages of subjects with pre-specified cut-off limit of ≥0.1 IU/mL (Diphtheria and Tetanus); ≥0.15 μg/mL (Hib); ≥0.35 μg/mL (Pneumococcal antigens, PnC); and ≥10 mIU/mL (Hepatitis B), evaluated using enzyme-linked immunosorbent assay (ELISA) at one month after 3 doses of infant series vaccination administered at 2, 4 and 6 months of age.
The immune response to pertussis antigens (PT, FHA, Pertactin, FIM) was measured as percentage of subjects with seroresponse (in initially seronegative infants, ≥4 times the lower limit of quantification (LLQ); in initially seropositive infants, at least 4 times prevaccination concentration) by ELISA and percentage of subjects with titer ≥1:8 (Polio types 1, 2, and 3) by neutralization test (NT) one month after 3 doses of infant series vaccination administered at 2, 4 and 6 months of age.