Table 5.
Evaluation criteria of influenza vaccine immunogenicity (HI antibody).
| Evaluation Criteria of Immunological Endpoint in Clinical Trials | ||
|---|---|---|
| 1. Absolute criteria of surrogate endpoint in placebo-controlled clinical trials | ||
| Eligible people | Adults | The elderly |
| GMT fold increase | 2.5 | 2 |
| Seroconversion rate | 40% | 30% |
| Seroprotection rate | 70% | 60% |
| 2. Relative criteria of common primary endpoints in non-inferiority trials | ||
| GMT | GMT ratio, 95% CI ≥ 2/3 | |
| Seroconversion | Value difference, 95% CI ≥ −10% | |
Definitions of the elderly are people of 60 (Europe and China) or 65 (US) years of age and older.