Background
Methods
Independent healthcare research database (IHRD)
Study participants
Vaccination status
Outcomes
Statistical analyses
Results
Parameter Examined | MMR Vaccinated Cohortb (n = 32,870) | Unvaccinated Cohortc (n = 43,538) |
---|---|---|
Person-Years | 224,492 | 434,637 |
Gender (%) | ||
Male | 17,468 (53.14%) | 23,202 (53.29%) |
Female | 15,402 (46.86%) | 20,336 (46.71%) |
Date of Birth | ||
mean ± std. (range) | 1995 ± 2.5 (1990–1999) | 1994 ± 2.5 (1990–1999) |
Number Diagnosed with Measles (ICD-9 Code: 055xxx) | 9 | 76 |
Parameter Examined | All Persons Diagnosed with Measles (n = 85) | Vaccinated Persons Diagnosed with Measles (n = 9)c | Unvaccinated Persons with Diagnosed Measles (n = 76)d |
---|---|---|---|
Gender (%) | |||
Male | 45 (53.41%) | 5 (55.56%) | 40 (52.63%) |
Female | 40 (47.06%) | 4 (44.44%) | 36 (47.37%) |
Date of Birth | |||
mean ± std. (range) | 1993 ± 2.1 (1990–1999) | 1994 ± 1.26 (1992–1996) | 1993 ± 2.2 (1990–1999) |
Age at Measles Diagnosis | |||
mean ± std. (range) | 1.65 ± 1.69 (0.15–7.08) | 1.27 ± 1.72 (0.15–5.39) | 1.69 ± 1.7 (0.18–7.08) |
Year of Measles Diagnosis | |||
mean ± std. (range) | 1995 ± 2.78 (1991–2003) | 1996 ± 1.9 (1993–1999) | 1994 ± 2.8 (1991–2003) |
Measles Diagnosis-Associated Complications | |||
No Complications | 78 (91.77%) | 8 (88.89%) | 70 (92.11%) |
Complications Specifiedb | 5 (5.88%) | 1 (11.11%) | 4 (5.26%) |
Unknown Complication Status | 2 (2.35%) | 0 (0%) | 2 (2.63%) |
Model | Variable | Hazard Ratio (95% CI) | VE (95% CI) | p-value | χ2 |
---|---|---|---|---|---|
I | Vaccinateda vs Unvaccinatedb (all ages) |
0.164
(0.082 to 0.328)
|
83.6%
(67.2 to 91.8%)
|
< 0.0001
|
26.2
|
Vaccinated vs Unvaccinated
(≥ 12 months-old)
c
|
0.291
(0.136 to 0.622)
|
70.9%
(37.8 to 86.4%)
|
0.0015
|
10.1
| |
II | Vaccinated vs Unvaccinated (all ages) |
0.193
(0.096 to 0.385)
|
80.7%
(61.5% to 90.4)
|
< 0.0001
|
21.7
|
Gender (Female vs Male) | 1.01 (0.659 to 1.544) | 0.97 | 0.002 | ||
County of Residence | 0.993 (0.982 to 1.004) | 0.24 | 1.40 | ||
Date of Birth
|
0.999
(0.999 to 0.999)
|
< 0.0001
|
30.2
| ||
Vaccinated vs Unvaccinated
(≥ 12 months-old)
c
|
0.346
(0.161 to 0.744)
|
65.4%
(25.6 to 83.9%)
|
0.00065
|
7.39
| |
Gender (Female vs Male) | 0.959 (0.544 to 1.692) | 0.89 | 0.02 | ||
County of Residence | 0.997 (0.982 to 1.011) | 0.65 | 0.21 | ||
Date of Birth
|
0.999
(0.999 to 0.999)
|
< 0.0001
|
18.8
|
Model | Variable | Hazard Ratio (95% CI) | VE (95% CI) | p-value | χ2 |
---|---|---|---|---|---|
I | Vaccinateda vs Unvaccinatedb
(≥ 12 months-old)
|
0.147
(0.071 to 0.305)
|
85.3%
(69.5 to 92.9%)
|
< 0.0001
|
26.5
|
Vaccinated vs Unvaccinated
(≥ 16 months-old)
|
0.100
(0.036 to 0.273)
|
90%
(72.7 to 86.4%)
|
< 0.0001
|
20.2
| |
Vaccinated vs Unvaccinated
(≥ 20 months-old)
|
0.061
(0.015 to 0.247)
|
93.9%
(75.3 to 98.5%)
|
< 0.0001
|
15.3
| |
II | Vaccinated vs Unvaccinated
(≥ 12 months-old)
|
0.173
(0.083 to 0.360)
|
82.7%
(64 to 91.7%)
|
< 0.0001
|
22.1
|
Gender (Female vs Male) | 1.032 (0.673 to 1.584) | 0.89 | 0.02 | ||
County of Residence | 0.994 (0.983 to 1.005) | 0.27 | 1.20 | ||
Date of Birth
|
0.999
(0.999 to 0.999)
|
< 0.0001
|
30
| ||
Vaccinated vs Unvaccinated
(≥ 16 months-old)
|
0.111
(0.040 to 0.303)
|
88.9%
(69.7 to 96%)
|
< 0.0001
|
18.4
| |
Gender (Female vs Male) | 1.109 (0.718 to 1.715) | 0.64 | 0.22 | ||
County of Residence | 0.995 (0.984 to 1.007) | 0.42 | 0.66 | ||
Date of Birth
|
0.999
(0.999 to 0.999)
|
< 0.0001
|
28.1
| ||
Vaccinated vs Unvaccinated
(≥ 20 months-old)
|
0.070
(0.017 to 0.287)
|
93%
(71.3 to 98.3%)
|
< 0.0001
|
13.7
| |
Gender (Female vs Male) | 1.027 (0.658 to 1.602) | 0.91 | 0.01 | ||
County of Residence | 0.996 (0.985 to 1.008) | 0.49 | 0.47 | ||
Date of Birth
|
0.999
(0.999 to 1.000)
|
< 0.0001
|
27.4
|
Discussion
Strengths/limitations
Year of Diagnosis | All Measles Cases | MMR Vaccinated Cohorta Diagnosed with Measles | Unvaccinated Cohortb Diagnosed with Measles |
---|---|---|---|
1991 | 18 | 0 | 18 |
1992 | 14 | 0 | 14 |
1993 | 11 | 1 | 10 |
1994 | 11 | 2 | 6 |
1995 | 8 | 1 | 7 |
1996 | 8 | 2 | 6 |
1997 | 6 | 1 | 5 |
1998 | 5 | 1 | 4 |
1999 | 4 | 1 | 3 |
2000 | 2 | 0 | 2 |
2001 | 0 | 0 | 0 |
2002 | 0 | 0 | 0 |
2003 | 1 | 0 | 1 |
2004 | 0 | 0 | 0 |
2005 | 0 | 0 | 0 |
2006 | 0 | 0 | 0 |
2007 | 0 | 0 | 0 |
2008 | 0 | 0 | 0 |
2009 | 0 | 0 | 0 |
Total | 85 | 9 | 76 |