TABLE 1

Estimated VE in Reported Pertussis Cases 2 to 11 mo of Age, by Hospitalization Status, 2005–2009

Age (mo)DosesCases (%)Controls (%)OR (95% CI)Estimated VE (95% CI)
All reported casesaN = 1446N = 28 828
 2–3N = 601N = 11 952
0175 (29.1)2081 (17.4)ReferenceReference
1401 (66.7)9634 (80.6)0.46 (0.38–0.56)53.7 (43.8–61.9)
 4–5N = 317N = 6397
055 (17.4)436 (6.8)ReferenceReference
2138 (43.5)4311 (67.4)0.25 (0.18–0.34)75.3 (65.7–82.3)
 6–11N = 528N = 10479
0110 (20.8)493 (4.7)ReferenceReference
270 (13.3)1698 (16.2)0.19 (0.14–0.27)80.8 (73.5–86.1)
3295 (55.9)7991 (76.3)0.17 (0.13–0.21)83.5 (79.1–87.0)
Hospitalized casesN = 589N = 11 721
 2–3N = 353N = 7031
0111 (31.4)1293 (18.4)ReferenceReference
1234 (66.3)5633 (80.1)0.45 (0.35–0.57)55.3 (42.7–65.1)
 4–5N = 119N = 2353
020 (16.8)143 (6.1)ReferenceReference
240 (33.6)1615 (68.6)0.17 (0.10–0.30)83.0 (70.2–90.3)
 6–11N = 117N = 2337
025 (21.4)115 (4.9)ReferenceReference
216 (13.7)416 (17.8)0.19 (0.10–0.37)81.3 (63.4–90.5)
359 (50.4)1734 (74.2)0.15 (0.09–0.25)85.0 (75.0–91.0)
  • a Reported cases include those hospitalized, not hospitalized, and of unknown hospitalization status.