TABLE 2

Estimated VE Among All Reported Pertussis Casesa Aged 1 to 3 y, 2005–2009

Age (y)DosesCases (%), N = 3123Controls (%), N = 61 636OR (95% CI)Estimated VE (95% CI)
1N = 870N = 15 170
0162 (18.6)774 (4.5)ReferenceReference
3662 (76.1)15 170 (87.6)0.21 (0.17–0.25)79.2 (75.0–82.8)
2N = 927N = 18 438
0140 (15.1)887 (4.8)ReferenceReference
3754 (81.3)16 354 (88.7)0.29 (0.24–0.36)70.7 (64.5–75.8)
3N = 1326N = 25 878
0150 (11.3)1186 (4.6)ReferenceReference
31141 (86.1)23 031 (89.0)0.41 (0.34–0.49)59.2 (51.0–66.0)
  • a Notified cases include those hospitalized, not hospitalized, and of unknown hospitalization status.