TABLE 1.
Hemagglutination inhibition response by MF59-adjuvanted H5N1 subunit influenza vaccine formulation and age cohorta
| Time | Parameter | Value for age cohortb |
|||
|---|---|---|---|---|---|
| Nonelderly |
Elderly |
||||
| Strain H5N1 A/turkey/Turkey (clade 2.2) | Strain H5N1 A/Vietnam (clade 1) | Strain H5N1 A/turkey/Turkey (clade 2.2) | Strain H5N1 A/Vietnam (clade 1) | ||
| Prebooster | GMT | 5 (5-5) | 6.35 (4.78-8.44) | 14 (5.79-33) | 20 (6.75-59) |
| Seroprotection rate, % | 0 (0-12) | 7 (1-23) | 29 (10-56) | 29 (10-56) | |
| 1 week after booster | GMT | 37 (19-70) | 103 (53-201) | 35 (13-95) | 59 (20-173) |
| GMR | 7.35 (3.86-14) | 16 (8.17-32) | 2.56 (1.25-5.24) | 2.95 (1.26-6.87) | |
| Seroprotection rate, % | 55 (36-74) | 69 (49-85) | 53 (28-77) | 65 (38-86) | |
| Seroconversion rate, % | 55 (36-74) | 66 (46-82) | 29 (10-56) | 35 (14-62) | |
| 3 weeks after booster | GMT | 72 (34-151) | 156 (73-336) | 102 (38-277) | 181 (67-490) |
| GMR | 14 (6.82-30) | 25 (11-53) | 7.38 (2.74-20) | 9.04 (2.97-28) | |
| Seroprotection rate, % | 62 (42-79) | 76 (56-90) | 76 (50-93) | 82 (57-96) | |
| Seroconversion rate, % | 62 (42-79) | 76 (56-90) | 59 (33-82) | 53 (28-77) | |
a
Primary vaccination with H5N1 A/Vietnam, 7.5 or 15 μg on study days 1 and 22; booster with H5N1 A/turkey/Turkey, 7.5 or 15 μg on study day 382. GMT, geometric mean titer; GMR, geometric mean ratio. Two-sided 95% confidence intervals are shown in parentheses. CHMP criteria: nonelderly, GMR > 2.5; seroprotection ≥ 70%; seroconversion ≥ 40%; elderly, GMR > 2.0; seroprotection ≥ 60%; seroconversion ≥ 30%.
b
Nonelderly cohort (n = 29), 18 to 60 years of age; elderly cohort (n = 17), >60 years of age.