Table 3.
Seroprotection and seroconversion rates based on hemagglutination inhibition titer by strain
| A(H3N2)-strain |
A(H1N1)-strain |
B-strain Victoria lineage |
B-strain Yamagata lineage |
|||||
|---|---|---|---|---|---|---|---|---|
| Statistic | Test Vaccine(N = 236) | Reference Vaccine(N = 237) | Test Vaccine(N = 236) | Reference Vaccine(N = 237) | Test Vaccine(N = 236) | Reference Vaccine(N = 237) | Test Vaccine(N = 236) | Reference Vaccine(N = 237) |
| Seroprotection Rates | ||||||||
| Overall (All participants) | ||||||||
| Pre-vaccination (Visit 1) | ||||||||
| m (%) | 152 (64.4) | 141 (59.5) | 101 (42.8) | 91 (38.4) | 17 (7.2) | 25 (10.5) | 15 (6.4) | 23 (9.7) |
| 95% CI | (57.9, 70.5) | (52.9, 65.8) | (36.4, 49.4) | (32.2, 44.9) | (4.3, 11.3) | (6.9, 15.2) | (3.6, 10.3) | (6.3, 14.2) |
| Post-vaccination (Visit 2) | ||||||||
| m (%) | 226 (95.8) | 236 (99.6) | 217 (91.9) | 219 (92.4) | 117 (49.6) | 137 (57.8) | 114 (48.3) | 113 (47.7) |
| 95% CI | (92.3, 97.9) | (97.7,100.0) | (87.7, 95.1) | (88.3, 95.4) | (43.0, 56.1) | (51.2, 64.2) | (41.8, 54.9) | (41.2, 54.2) |
| Adults 18–60 years | ||||||||
| Pre-vaccination (Visit 1) | ||||||||
| N | 118 | 121 | 118 | 121 | 118 | 121 | 118 | 121 |
| m (%) | 73 (61.9) | 76 (62.8) | 53 (44.9) | 53 (43.8) | 9 (7.6) | 12 (9.9) | 9 (7.6) | 13 (10.7) |
| 95% CI | (52.5,70.6) | (53.6, 71.4) | (35.7, 54.3) | (34.8, 53.1) | (3.5, 14.0) | (5.2, 16.7) | (3.5, 14.0) | (5.8, 17.7) |
| Post-vaccination (Visit 2) | ||||||||
| N | 118 | 121 | 118 | 121 | 118 | 121 | 118 | 121 |
| m (%) | 114 (96.6) | 121 (100.0) | 112 (94.9) | 115 (95.0) | 61 (51.7) | 73 (60.3) | 63 (53.4) | 62 (51.2) |
| 95% CI | (91.5, 99.1) | (97.0, 100.0) | (89.3, 98.1) | (89.5, 98.2) | (42.3, 61.0) | (51.0, 69.1) | (44.0, 62.6) | (42.0, 60.4) |
| Elderly adults ≥ 61 years | ||||||||
| Pre-vaccination (Visit 1) | ||||||||
| N | 118 | 116 | 118 | 116 | 118 | 116 | 118 | 116 |
| m (%) | 79 (66.9) | 65 (56.0) | 48 (40.7) | 38 (32.8) | 8 (6.8) | 13 (11.2) | 6 (5.1) | 10 (8.6) |
| 95% CI | (57.7, 75.3) | (46.5, 65.2) | (31.7, 50.1) | (24.3, 42.1) | (3.0, 12.9) | (6.1, 18.4) | (1.9, 10.7) | (4.2, 15.3) |
| Post-vaccination (Visit 2) | ||||||||
| N | 118 | 116 | 118 | 116 | 118 | 116 | 118 | 116 |
| m (%) | 112 (94.9) | 115 (99.1) | 105 (89.0) | 104 (89.7) | 56 (47.5) | 64 (55.2) | 51 (43.2) | 51 (44.0) |
| 95% CI | (89.3, 98.1) | (95.3, 100.0) | (81.9, 94.0) | (82.6, 94.5) | (38.2, 56.9) | (45.7, 64.4) | (34.1, 52.7) | (34.8, 53.5) |
| Seroconversion Rates | ||||||||
| Overall (All subjects) | ||||||||
| Post-vaccination (Visit 2) | ||||||||
| m* (%) | 168 (71.2) | 178 (75.1) | 186 (78.8) | 183 (77.2) | 107 (45.3) | 121 (51.1) | 105 (44.5) | 98 (41.4) |
| 95% CI | (65.0,76.9) | (69.1,80.5) | (73.0,83.8) | (71.3,82.4) | (38.9,51.9) | (44.5,57.6) | (38.0,51.1) | (35.0,47.9) |
| Adults aged 18–60 years | ||||||||
| Post-vaccination (Visit 2) | ||||||||
| N | 118 | 121 | 118 | 121 | 118 | 121 | 118 | 121 |
| m* (%) | 89 (75.4) | 90 (74.4) | 99 (83.9) | 91 (75.2) | 57 (48.3) | 66 (54.5) | 57 (48.3) | 56 (46.3) |
| 95% CI | (66.6,82.9) | (65.6,81.9) | (76.0,90.0) | (66.5,82.6) | (39.0,57.7) | (45.2,63.6) | (39.0,57.7) | (37.2,55.6) |
| Elderly adults aged ≥ 61 years | ||||||||
| Post-vaccination (Visit 2) | ||||||||
| N | 118 | 116 | 118 | 116 | 118 | 116 | 118 | 116 |
| m* (%) | 79 (66.9) | 88 (75.9) | 87 (73.7) | 92 (79.3) | 50 (42.4) | 55 (47.4) | 48 (40.7) | 42 (36.2) |
| 95% CI | (57.7,75.3) | (67.0,83.3) | (64.8,81.4) | (70.8,86.3) | (33.3,51.8) | (38.1,56.9) | (31.7,50.1) | (27.5,45.6) |
Abbreviations: CI: confidence interval
Notes. n: Number of participants with non-missing data; m: Number of seroprotected participants, m*: Number of seroconverted subjects
Seroprotection defined as an HI titer≥40
Seroconversion defined as a pre vaccination titer <10 and a post-vaccination titer ≥ 40 or a pre vaccination titer ≥10 and at least a 4 fold post-vaccination increase
95% CI was calculated using Clopper-Pearson method