TABLE 1

Timing of First Vaccination a and Occurrence of Seizure, Stratified by Vaccine: Vaccines Recommended at 2 Months of Age

VaccineAge at Receipt, dSeizuresDays Patient TimeIRR c 95% Confidence Interval
Exposed b UnexposedExposedUnexposed
DTaP38–92 107324923091.260.65–2.45
93–730 16211961.560.19–12.92
PCV38–92 97424923091.120.56–2.24
93–730 17242241.330.16–10.84
HIB38–92 87123721971.040.50–2.16
93–730 16211961.560.19–12.92
IPV38–92 107324923091.260.65–2.45
93–730 16211961.560.19–12.92
Rotavirus38–92 103032011201.170.57–2.39
93–730 15481680.700.08–5.99
  • PCV, pneumococcal conjugated vaccine (either PCV-7 or PCV-13).

  • a Excluding Hepatitis B virus vaccine.

  • b Exposure window = postvaccination days 0 to 2 (DTaP, PCV, HIB, and IPV vaccines) and days 0 to 7 (rotavirus vaccine): 38–92 d = vaccine administered as recommended; 93–730 d = vaccine delayed.

  • c The IRR represents, among children with their first diagnosis of seizure, the incidence rate of seizure in an exposed time period (risk window) after vaccination versus the incidence rate of seizure in unexposed time periods (control window).