TABLE 2

Demographic Characteristics of Participants Included in Analyses Estimating Tdap VE, Duration of Protection, and Brand Effectiveness Against Pertussis

CharacteristicCases (n = 836)Controls (n = 2322)Pc
Birth year, n (%)
 1993–1997386 (46.2)1076 (46.3)Not applicablea
 1998–2000450 (53.8)1246 (53.7)
Gender, n (%)
 Male428 (51.2)1191 (51.3).80
 Female406 (48.6)1122 (48.3)
 Unknown2 (0.2)9 (0.4)
Race, n (%)
 White304 (36.3)570 (24.5).003
 Other79 (9.5)232 (10.0)
 Unknown453 (54.2)1520 (65.5)
Ethnicity, n (%)
 Non-Hispanic304 (36.4)625 (26.9).03
 Hispanic79 (9.4)217 (9.4)
 Unknown453 (54.2)1480 (63.7)
Childhood series vaccination, n (%)
 Complete, on-schedule seriesb506 (60.5)1357 (58.4).29
Tdap vaccination status, n (%)
 No162 (19.4)229 (9.9)<.0001
 Yes674 (80.6)2093 (90.1)
Age at Tdap, median (range), y11 (10–17)11 (10–18).43
Time since Tdap vaccination, median (range), mo
 Overall33 (1–73)31 (0–84).02
 Birth years 1998–200022 (1–47)19 (0–47).10
 Birth years 1993–199744 (2–73)45 (0–84).16
Tdap brand, n (%)
 Adacel136 (20.2)342 (16.3).05
 Boostrix387 (57.4)1245 (59.5)
 Unknown brand151 (22.4)506 (24.2)
  • a Cases and controls were matched on birth year, and therefore no P value was calculated.

  • b A complete and on-schedule primary series is considered the following: doses 1 through 3 before the first birthday, dose 4 on or after the first birthday and before the second birthday, and dose 5 on or after the fourth birthday and before the seventh birthday.

  • c P values do not apply to unknown data.