Table 2.
Serum NA-Inhibiting Antibody Titers by Vaccine Group as Measured With Enzyme-Linked Lectin Assay
| Vaccine Group | Dose, µg | NA-Inhibiting Antibody Titer |
|||
|---|---|---|---|---|---|
| Titer for 1st Dose, GMT (95% CI) | Ferrets With Titer ≥20, No.a | Titer for 2nd Dose, GMT (95% CI) | Ferrets With Titer ≥20, No.a | ||
| Saline | 0 | <20 | 0 | <20 | 0 |
| Unadjuvanted | 3.75 | <20 | 0 | 10 (4.5–22.2) | 1 |
| 15 | <20 | 0 | 6.3 (3.5–11.4) | 1 | |
| 45 | <20 | 0 | 15.8 (6.6–38.3) | 3 | |
| MF59 | 3.75 | 7.9 (3.7–16.8) | 2 | 200.0 (64.8–617.3)b | 5 |
| 15 | 17.8 (2.7–115.0) | 2 | 356.4 (80.7–1573)b | 5 | |
| AS03 | 3.75 | 35.6 (11.1–114.3) | 5 | 800.0 (285.9–2238)b | 6 |
| 15 | 35.6 (12.2–104.0) | 5 | 1796 (615.5–5241)b,c | 6 | |
Abbreviations: CI, confidence interval; GMT, geometric mean titer; NA, neuraminidase.
a There were 6 ferrets per group. The starting dilution was 1:20, with titers <20 arbitrarily set at 5.
b P < .05 by analysis of variance for comparison with saline control and unadjuvanted vaccine group.
c P < .05 for comparison with MF59-adjuvanted, 3.75-µg vaccine group.