Table 2.
Vaccine Effectiveness during the 2018-2019 Season.
| a) Children (≤ 15 years) | |||||
|---|---|---|---|---|---|
| 1) Total | n | Vaccinated, Unvaccinated cases | Vaccinated, Unvaccinated controls | Crude VE (95% CI) | Adjusted VEb(95% CI) |
| Any Influenza | 714 | 139, 233 | 175, 167 | 43.1 % (23.3 to 57.8) * | 41.3% (19.7 to 57.2) * |
| Influenza total A | 699 | 137, 220 | 175, 167 | 40.6 % (19.7 to 56.0) * | 38.3% (15.1 to 55.1) * |
| Influenza A (H1N1) pdm09 | 475 | 50, 83 | 175, 167 | 42.5 % (13.4 to 61.8) * | 34.5% (-2.3 to 58.1) |
| Influenza A (H3N2) | 566 | 87, 137 | 175, 167 | 39.4 % (14.7 to 57.0) * | 39.8% (13.8 to 57.9) * |
| 2) ≤ 6 yearsa | |||||
| Any Influenza | 348 | 75, 98 | 103, 72 | 46.5 % (18.1 to 65.0) * | 44.8% (14.1 to 64.5) * |
| Influenza total A | 347 | 75, 97 | 103, 72 | 46.0% (17.2 to 64.7) * | 43.8% (12.5 to 63.9) * |
| Influenza A (H1N1) pdm09 | 235 | 22, 38 | 103, 72 | 59.5% (25.9 to 77.9) * | 48.3% (-0.9 to 73.5) |
| Influenza A (H3N2) | 287 | 53, 59 | 103, 72 | 37.2% (-1.3 to 61.1) | 38.4% (-0.4 to 62.2) |
| 3) 7-15 years | |||||
| Any Influenza | 366 | 64, 135 | 72, 95 | 37.4% (4.1 to 59.2) * | 36.2% (-0.2 to 59.4) |
| Influenza total A | 352 | 62, 123 | 72, 95 | 33.5% (-2.5 to 56.8) | 30.2% (-11.1 to 56.2) |
| Influenza A (H1N1) pdm09 | 240 | 28, 45 | 72, 95 | 17.9% (-44.1 to 53.2) | 15.3% (-56.9 to 54.2) |
| Influenza A (H3N2) | 279 | 34, 78 | 72, 95 | 42.5% (4.6 to 65.3) * | 40.0% (-2.2 to 64.8) |
| b) Adults (≥ 16 years) | |||||
| 1) Total | |||||
| Any Influenza | 619 | 76, 201 | 135, 207 | 42.0 % (18.4 to 58.8) * | 42.3% (17.9 to 59.5) * |
| Influenza total A | 612 | 75, 195 | 135, 207 | 41.0 % (16.9 to 58.2) * | 39.3% (13.5 to 57.4) * |
| Influenza A (H1N1) pdm09 | 417 | 15, 60 | 135, 207 | 61.7 % (29.7 to 79.1) * | 56.7% (19.1 to 76.8) * |
| Influenza A (H3N2) | 537 | 60, 135 | 135, 207 | 31.9% (1.0 to 53.1) * | 33.2% (1.5 to 54.6) * |
| 2) 16-64 years | |||||
| Any Influenza | 555 | 61, 182 | 119, 193 | 45.6% (21.4 to 62.4) * | 43.4% (17.3 to 61.2) * |
| Influenza total A | 548 | 60, 176 | 119, 193 | 44.7% (19.8 to 61.9) * | 41.7% (14.4 to 60.3) * |
| Influenza A (H1N1) pdm09 | 381 | 13, 56 | 119, 193 | 62.3% (28.2 to 80.3) * | 56.2% (14.9 to 77.5) * |
| Influenza A (H3N2) | 479 | 47, 120 | 119, 193 | 36.5% (4.5 to 57.7) * | 34.5% (0.3 to 56.9) * |
| 3) ≥ 65 years | |||||
| Any Influenza | 64 | 15, 19 | 16, 14 | 30.9% (-85.2 to 74.2) | 32.5% (-82.4 to 75.0) |
| Influenza total A | 64 | 15, 19 | 16, 14 | 30.9% (-85.2 to 74.2) | 32.5% (-82.4 to 75.0) |
| Influenza A (H1N1) pdm09 | 36 | 2, 4 | 16, 14 | 56.3% (-176.2 to 93.1) | 59.7% (-176.6 to 94.1) |
| Influenza A (H3N2) | 58 | 13, 15 | 16, 14 | 24.2% (-112.9 to 73.0) | 25.7% (-110.2 to 73.7) |
VE: vaccine effectiveness, CI: confidence interval
Influenza total A: Influenza A (H1N1) pdm09 and Influenza A (H3N2)
n: total numbers of cases
* Statistically significant
a Eighteen patients aged ≤ 11 months were included.
b VE adjusted for age group, sex, month of onset of influenza infection (December vs. January vs. February and later), comorbidity in total children; VE adjusted for sex, month of onset of influenza infection (December vs. January vs. February and later) and comorbidity in each age group of children.
c VE adjusted for age group, sex, month of onset of influenza infection (December vs. January vs. February vs. March and later), comorbidity in total adults; VE adjusted for sex, month of onset of influenza infection (December vs. January vs. February vs. March and later), comorbidity in the younger adult group (16–64 years); VE adjusted for sex, month of onset of influenza infection (December and January vs. February and later) and comorbidity in the older adult group (≥ 65 years).