Table 5.
Impact of routine and catch-up herpes zoster vaccination on hospitalised herpes zoster by time since cohorts were first eligible for vaccination
| Period | Age on 1 Sept 2013 (age when first eligible for vaccination) | Average cumulative uptake* | Expected events† | Observed events | Incidence rate ratio‡ (95% CI) |
Expected incidence per 10 000 person-years | Incidence reduction per 10 000 person-years (95% CI) |
Vaccine effectiveness§ (95% CI) |
| Routine cohorts | ||||||||
| First year after vaccine eligibility | 66–70 years | 47% | 823 | 686 | 0.83 (0.77 to 0.90) | 2.94 | 0.50 (0.30 to 0.68) | 36% (22% to 49%) |
| (70–71 years) | ||||||||
| Second year after vaccine eligibility | 67–70 years | 64% | 658 | 519 | 0.78 (0.72 to 0.86) | 3.27 | 0.71 (0.47 to 0.92) | 34% (22% to 44%) |
| (70–71 years) | ||||||||
| Third year after vaccine eligibility | 68–70 years | 71% | 538 | 395 | 0.73 (0.66 to 0.81) | 3.66 | 0.99 (0.71 to 1.25) | 38% (27% to 48%) |
| (70–71 years) | ||||||||
| Fourth year after vaccine eligibility | 69–70 years | 75% | 394 | 311 | 0.78 (0.70 to 0.87) | 4.10 | 0.90 (0.51 to 1.25) | 29% (17% to 40%) |
| (70–71 years) | ||||||||
| Fifth year after vaccine eligibility | 70 years | 77% | 205 | 116 | 0.56 (0.46 to 0.67) | 4.61 | 2.04 (1.52 to 2.47) | 57% (43% to 69%) |
| (70–71 years) | ||||||||
| All years of the programme | 66–70 years | 62% | 2619 | 2027 | 0.77 (0.73 to 0.81) | 3.41 | 0.78 (0.65 to 0.91) | 37% (31% to 43%) |
| (70–71 years) | ||||||||
| Catch-up cohorts | ||||||||
| First year after vaccine eligibility | 74–79 years | 48% | 1277 | 976 | 0.76 (0.71 to 0.81) | 6.26 | 1.49 (1.16 to 1.79) | 50% (39% to 60%) |
| (78–80 years) | ||||||||
| Second year after vaccine eligibility | 75–79 years | 62% | 1136 | 770 | 0.67 (0.63 to 0.73) | 7.03 | 2.29 (1.93 to 2.63) | 52% (44% to 60%) |
| (78–80 years) | ||||||||
| Third year after vaccine eligibility | 77–79 years | 63% | 961 | 656 | 0.68 (0.62 to 0.73) | 7.92 | 2.57 (2.12 to 2.98) | 51% (42% to 59%) |
| (78–80 years) | ||||||||
| Fourth year after vaccine eligibility | 78–79 years | 63% | 756 | 554 | 0.72 (0.66 to 0.79) | 9.00 | 2.50 (1.90 to 3.05) | 44% (34% to 54%) |
| (78–80 years) | ||||||||
| Fifth year after vaccine eligibility | 79 years | 59% | 251 | 180 | 0.70 (0.61 to 0.82) | 10.17 | 3.02 (1.86 to 4.01) | 50% (31% to 66%) |
| (79–80 years) | ||||||||
| All years of the programme | 74–79 years | 57% | 4382 | 3136 | 0.71 (0.68 to 0.74) | 7.36 | 2.10 (1.88 to 2.32) | 50% (45% to 55%) |
| (78–80 years) | ||||||||
*Calculated by taking the mean of the cumulative uptake values in each month from October to September of the relevant years and cohorts.
†Expected if vaccine not introduced; based on model results for unvaccinated cohorts.
‡Estimated from the Poisson regression model with a quadratic time trend, cubic age effect and the factor for vaccine eligibility.
§Effectiveness required to generate the observed reduction given the impact and coverage.