Mean respiratory tract symptom scores per day throughout the influenza season
| Vaccine | Placebo | p-value | |
| Scores n | 344 | 344 | |
| Upper respiratory tract | |||
| Runny or stuffy nose | 0.30 | 0.26 | 0.11 |
| Sneezing | 0.12 | 0.10 | 0.29 |
| Burning or watery eyes | 0.04 | 0.03 | 0.73 |
| Sore throat | 0.07 | 0.06 | 0.10 |
| Hoarseness | 0.03 | 0.03 | 0.64 |
| Fever or shivering | 0.03 | 0.03 | 0.85 |
| Headache | 0.10 | 0.09 | 0.41 |
| Myalgia | 0.04 | 0.02 | 0.08 |
| Total symptom score | 0.75 | 0.65 | 0.13 |
| Lower respiratory tract | |||
| Cough during the day | 0.25 | 0.23 | 0.61 |
| Cough during the night | 0.11 | 0.11 | 0.98 |
| Wheeze during the day | 0.04 | 0.04 | 0.85 |
| Wheeze during the night | 0.03 | 0.04 | 0.39 |
| Difficult breathing or shortness of breath | 0.13 | 0.14 | 0.90 |
| Total symptom score | 0.58 | 0.58 | 1.00 |
Each separate score ranged from 0 (absent) to 3 (severe)