Table 5.
HAI GMTs at baseline and day 21 by previous year's vaccination.
| HAI GMT (95% CI) |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| A/H1N1 |
A/H3N2 |
B Victoria lineage |
B Yamagata lineage |
|||||||
| Age | Vaccine | Day | Vaccinated previous year | Not vaccinated previous year | Vaccinated previous year | Not vaccinated previous year | Vaccinated previous year | Not vaccinated previous year | Vaccinated previous year | Not vaccinated previous year |
| 18–60 y | Pooled IIV4 | N = 173 | N = 659 | N = 173 | N = 658 | N = 173 | N = 658 | N = 173 | N = 658 | |
| 0 | 169 (138, 206) | 47.8 (42.2, 54.2) | 160 (130, 198) | 35.5 (31.4, 40.1) | 156 (129, 189) | 47.8 (42.8, 53.5) | 532 (448, 633) | 187 (167, 210) | ||
| 21 | 355 (305, 413) | 701 (644, 764) | 395 (338, 461) | 530 (482, 583) | 495 (424, 578) | 779 (721, 842) | 1077 (933, 1244) | 1938 (1806, 2080) | ||
| Pooled IIV3 | N = 60 | N = 218 | N = 60 | N = 218 | N = 36 | N = 104 | N = 24 | N = 114 | ||
| 0 | 160 (113, 228) | 52.4 (42.2, 65.2) | 147 (104, 208) | 29.9 (24.4, 36.6) | 171 (112, 261) | 46.0 (34.7, 61.0) | 570 (344, 944) | 246 (187, 325) | ||
| 21 | 365 (274, 488) | 815 (684, 971) | 387 (282, 532) | 719 (611, 846) | 484 (346, 677) | 850 (692, 1044) | 973 (657, 1441) | 1959 (1673, 2294) | ||
| >60 y | Pooled IIV4 | N = 404 | N = 424 | N = 404 | N = 423 | N = 403 | N = 424 | N = 404 | N = 423 | |
| 0 | 76.9 (67.4, 87.7) | 26.0 (22.5, 30.0) | 113 (99.2, 129) | 36.9 (31.3, 43.5) | 100 (89.2, 113) | 39.2 (33.7, 45.6) | 274 (248, 304) | 94.5 (82.1, 109) | ||
| 21 | 176 (156, 197) | 270 (232, 314) | 275 (247, 306) | 462 (406, 525) | 221 (198, 246) | 367 (327, 412) | 509 (464, 558) | 835 (758, 921) | ||
| Pooled IIV3 | N = 131 | N = 143 | N = 131 | N = 142 | N = 66 | N = 71 | N = 65 | N = 72 | ||
| 0 | 86.4 (67.9, 110) | 24.2 (18.8, 31.2) | 143 (114, 180) | 37.5 (28.0, 50.3) | 97.7 (76.0, 125) | 45.0 (30.0, 67.5) | 300 (232, 389) | 101 (69.7, 147) | ||
| 21 | 173 (142, 212) | 399 (316, 504) | 305 (254, 367) | 543 (432, 683) | 190 (153, 237) | 459 (329, 640) | 462 (368, 580) | 1011 (830, 1232) | ||
Values are for all participants vaccinated with available pre- and post-vaccination HAI titers. Abbreviations: CI, confidence interval; GMT, geometric mean titer; HAI, hemagglutination inhibition; IIV3, trivalent inactivated influenza vaccine; IIV4, quadrivalent inactivated influenza vaccine.