Table 3:
Sensitivity analyses for the vaccine effectiveness of one and two doses of the MMR vaccine by birth cohort for scenarios 1 and 2* (n = 88)
| Coverage | Birth cohort; vaccine effectiveness, %
|
|||||||
|---|---|---|---|---|---|---|---|---|
| 1980–1984
|
1985–1989
|
1990–1991
|
1992–1994
|
1995–2002
|
||||
| One dose | One dose | One dose | Two doses | One dose | Two doses | One dose | Two doses | |
| Baseline | 81.6 | 59.4 | 76.7 | 88.0 | 49.2 | 66.3 | 76.5 | 83.9 |
| Scenario 1* | 87.7 | 73.9 | 83.1 | 89.4 | 74.6 | 83.1 | 76.5 | 83.9 |
| Scenario 2* | ||||||||
| PPV −5% | 81.9 | 58.7 | 71.0 | 84.7 | −72.5† | 44.6 | 54.9 | 76.6 |
| PPV −3% | 84.3 | 63.2 | 73.4 | 86.2 | 10.4 | 53.6 | 66.7 | 79.6 |
| PPV +3% | 90.9 | 75.3 | 79.7 | 89.6 | 65.2 | 78.1 | 82.1 | 87.8 |
| PPV +5% | 92.9 | 78.9 | 81.6 | 90.5 | 71.6 | 85.6 | 84.7 | 100.0 |
Note: MMR = measles–mumps–rubella, PPV = proportion of the population vaccinated.
*
Patients whose immunization status was unknown were assumed to have received zero, one and two doses of the vaccine with equal probability (scenario 1). Higher and lower levels of coverage for the vaccine were assumed for the population (scenario 2).
†
Vaccine effectiveness estimate was negative because the proportion of the population vaccinated (PPV) was lower than the proportion of cases vaccinated.