Table 4.
Meta-analysis on primary outcome for adults and children
| Type of influenza | # Influenza seasons | Sample size (placebo group) | # Influenza cases (placebo group) | Natural attack rate % (lower 95% CI, upper 95% CI) | I 2 |
|---|---|---|---|---|---|
| Adults | |||||
| All | 19 | 28748 | 627 | 3.50 (2.30, 4.60) | 98.0% |
| Influenza A | 19 | 28748 | 482 | 2.32 (1.47, 3.17) | 97.90% |
| Influenza B | 19 | 28748 | 150 | 0.59 (0.28, 0.91) | 98.11% |
| Children | |||||
| All | 13 | 6187 | 1040 | 15.20 (11.40, 18.90) | 94.0% |
| Influenza A | 10 | 5432 | 714 | 12.27 (8.56, 15.97) | 94.59% |
| Influenza B | 11 | 5926 | 341 | 5.50 (3.49, 7.51) | 94.69% |
Abbreviations: CI confidence interval.