Table 2.
Serum antibody (Ab) responses on days 7, 28 and 56 following administration of A(H5N1) inactivated influenza vaccine (IIV)
| |
Day 7 |
|
Day 28 |
|
Day 56* |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n (%) with ≥1:40 Ab titer2 | Subjects with ≥4-fold Ab rise |
n (%) with ≥1:40 Ab titer | Subjects with ≥4-fold Ab rise |
n (%) with ≥1:40 Ab titer | Subjects with ≥4-fold Ab rise |
|||||||||
| Test antigen | Study group | n | GMT1 | n (%)2 | GMT1 | GMT | n (%) | GMT | GMT | n (%) | GMT | |||
| Hemagglutination inhibition assay | ||||||||||||||
| 17/t/Tur (H5N2) | Primed | 19 | 6.0 | 4 (21.1) | 5 (26.3) | 69.6 | 43.0 | 11 (57.9) | 13 (68.4) | 160.0 | 62.0 | 12 (63.2) | 15 (78.9) | 145.9 |
| Control | 24 | 3.1 | 1 (4.2) | 2 (8.3) | 28.3 | 5.8 | 3 (12.5) | 6 (25.0) | 50.4 | 7.7 | 5 (20.8) | 10 (41.7) | 32.5 | |
| NIBRG-23 (H5N1) | Primed | 19 | 7.5 | 5 (26.3) | 5 (26.3) | 139.3 | 32.1 | 11 (57.9) | 11 (57.9) | 205.9 | 44.6 | 14 (73.7) | 14 (73.7) | 124.9 |
| Control | 24 | 3.1 | 1 (4.2) | 2 (8.3) | 28.3 | 5.9 | 3 (12.5) | 7 (29.2) | 44.2 | 9.2 | 7 (29.2) | 12 (50.0) | 33.6 | |
| Indo (H5N1) | Primed | 19 | 6.5 | 2 (10.5) | 8 (42.1) | 23.8 | 35.9 | 12 (63.2) | 12 (63.2) | 169.5 | 49.8 | 14 (73.7) | 15 (78.9) | 110.6 |
| Control | 24 | 3.4 | 2 (8.3) | 2 (8.3) | 40.0 | 8.7 | 4 (16.7) | 10 (41.7) | 35.3 | 11.9 | 9 (37.5) | 13 (54.2) | 44.5 | |
| d/Pot (H5N2) | Primed | 19 | 7.2 | 5 (26.3) | 7 (36.8) | 36.2 | 32.1 | 11 (57.9) | 14 (73.7) | 80.0 | 35.9 | 14 (73.7) | 14 (73.7) | 92.8 |
| |
Control |
24 |
3.1 |
1 (4.2) |
3 (12.5) |
15.9 |
5.9 |
4 (16.7) |
7 (29.2) |
48.8 |
9.2 |
8 (33.3) |
10 (41.7) |
56.6 |
| Microneutralization assay | ||||||||||||||
| 17/t/Tur (H5N2) | Primed | 19 | 138.3 | 15 (78.9) | 12 (63.2) | 380.5 | 413.1 | 19 (100) | 18 (94.7) | 470.3 | 370.3 | 19 (100) | 18 (94.7) | 387.9 |
| Control | 24 | 20.6 | 7 (29.2) | 11 (45.8) | 58.4 | 49.0 | 14 (58.3) | 18 (75.0) | 80.0 | 142.5 | 22 (91.7) | 23 (95.8) | 155.3 | |
| Indo (H5N1) | Primed | 19 | 66.7 | 12 (63.2) | 11 (57.9) | 219.3 | 165.9 | 17 (89.5) | 18 (94.7) | 194.0 | 239.0 | 19 (100) | 19 (100) | 239.0 |
| Control | 24 | 15.9 | 6 (25.0) | 11 (45.8) | 48.3 | 31.3 | 11 (45.8) | 16 (66.7) | 61.7 | 73.4 | 21 (87.5) | 23 (95.8) | 80.0 | |
17/t/Tur (H5N2): A/17/turkey/Turkey/05/133 (H5N2) LAIV strain; NIBRG-23 (H5N1): A/turkey/Turkey/5/05 (H5N1) PR8-based candidate vaccine virus; Indo (H5N1): A/Indonesia/5/2005 (H5N1) PR8-based candidate vaccine virus; d/Pot (H5N2): A/17/duck/Potsdam/86/92 (H5N2) LAIV strain; Ab, antibody;
Day 56 is counted relative to the first dose of IIV and corresponds to Day 28 after the second dose of the IIV;
statistically significantly higher GMT values in the primed group compared to the control group are shown in bold (Mann-Whitney U test; p < 0.05);
statistically significantly higher proportions of subjects in the primed group compared to the control group are shown in bold (Fisher exact test, 2-tailed; p < 0.05); see Supplementary materials for the exact P values (Table S3).