TABLE 3.

Number of Doses and Unadjusted Pertussis VE, Stratified According to Age

n (%)VE, %95% CI
CaseControl
Age 6–23 moN = 92N = 445
    0 dose20 (22)11 (2)Reference
    1 dose8 (9)9 (2)50.5−71.1 to 86.3
    2 doses12 (13)53 (12)80.141.3 to 93.2
    3 doses41 (44)275 (62)93.383.1 to 97.4
    4 doses11 (12)97 (22)95.185.1 to 98.4
Age 24–59 moN = 92N = 448
    0 dose28 (30)3 (1)Reference
    1 dose5 (5)3 (1)93.519.4 to 99.5
    2 doses1 (1)5 (1)99.487.3 to 99.9
    3 doses6 (7)22 (5)98.486.0 to 99.8
    4 doses52 (57)398 (88)99.395.0 to 99.9
    5 doses017 (4)100
AllN = 184N = 893
    0 dose48 (26)14 (2)Reference
    1 dose13 (7)12 (1)70.813.9 to 90.1
    2 doses13 (7)58 (6)89.571.3 to 96.2
    3 doses47 (26)297 (33)95.689.7 to 98.0
    4 doses63 (34)495 (55)97.494.2 to 98.8
    5 doses017 (2)100