Table 3.
Serum HAI and MNt antibody responses to the homologous vaccine antigen, influenza A/Chicken/Hong Kong/G9/97 (H9N2)
| Age group | 18–38 | 44–59 | ||||
|---|---|---|---|---|---|---|
| 7.5 mcg (n=31) | 30 mcg (n=30) | All (n=61) | 7.5 mcg (n=28) | 30 mcg (n=32) | All (n=60) | |
| HAI* | ||||||
| SCR (95% CI) | ||||||
| Day 28 | 40 (23, 59) | 70 (51, 85) | 55 (42, 68) | 61 (41, 79) | 41 (24, 59) | 50 (37, 63) |
| Day 56 | 44 (26, 65) | 72 (53, 87) | 59 (45, 87) | 54 (33, 73) | 56 (38, 74) | 55 (42, 68) |
| GMTs (95%CI) | ||||||
| Day 0 | 11 (8, 16) | 9 (6, 14) | 10 (8, 13) | 13 (9, 19) | 10 (8, 14) | 11 (9, 15) |
| Day 28 | 24 (18, 33) | 41 (27, 62) | 32 (24, 41) | 46 (28, 77) | 27 (21, 36) | 35 (27, 46) |
| Day 56 | 31 (22, 44) | 57 (39, 82) | 43 (33, 55) | 38 (23, 62) | 36 (27, 47) | 36 (28, 47) |
| SCF (95% CI) | ||||||
| Day 28 | 2.1 (1.6, 2.9) | 4.5 (3.2, 6.3) | 3.1 (2.4, 3.9) | 3.6 (2.5, 5.3) | 2.7 (1.8, 3.8) | 3.1 (2.4, 4.0) |
| Day 56 | 2.8 (1.9, 4.0) | 7.1 (4.6, 11.0) | 4.5 (3.3, 6.1) | 3.0 (2.0, 4.5) | 3.4 (2.4, 5.0) | 3.2 (2.5, 4.2) |
| % with titer ≥32 (95%CI) | ||||||
| Day 0 | 19 (7,37) | 10 (2, 27) | 15 (7, 26) | 18 (6,37) | 16 (5,33) | 17 (8, 29) |
| Day 28 | 50 (31, 69) | 63 (44, 80) | 57 (43, 69) | 75 (55, 89) | 56 (38, 74) | 65 (52, 77) |
| Day 56 | 67 (46, 84) | 86 (68, 96) | 77 (64, 87) | 62 (41, 80) | 69 (50, 84) | 66 (52, 78) |
| MNt | ||||||
| SCR | ||||||
| Day 28 | 63 (44, 80) | 70 (51, 85) | 67 (53, 78) | 36 (19, 56) | 44 (26, 62) | 40 (28, 54) |
| Day 56 | 93 (76, 99) | 97 (82, 100) | 95 (85, 99) | 58 (37, 77) | 75 (57, 89) | 67 (54, 79) |
| GMTs (95%CI) | ||||||
| Day 0 | 3 (2, 4) | 3 (2, 3) | 3 (2,3) | 8 (6, 12) | 6 (5, 8) | 7 (6, 9) |
| Day 28 | 13 (8, 19) | 20 (13, 31) | 16 (12, 21) | 29 (16, 53) | 21 (14, 30) | 24 (17, 34) |
| Day 56 | 36 (22, 58) | 69 (45, 105) | 50 (36, 69) | 37 (22, 61) | 44 (30, 66) | 41 (30, 55) |
| SCF (95% CI) | ||||||
| Day 28 | 4.2 (3.1, 5.8) | 7.9 (5.3, 11.9) | 5.8 (4.4, 7.5) | 3.4 (2.3, 5.2) | 3.3 (2.2, 4.8) | 3.3 (2.6, 4.4) |
| Day 56 | 12.4 (8.4, 18.2) | 30.1 (19.2, 47.4) | 19.6 (14.3, 26.9) | 4.4 (2.9, 6.6) | 6.9 (4.6, 10.5) | 5.7 (4.2, 7.6) |
*
Abbreviations: HAI = hemagglutination inhibition, GMT = geometric mean titer, SCF = seroconversion factor, SCR = seroconversion rate, MNt = microneutralization