Table 1.
Demographic characteristics of cases in three clinical trials
| Variable | No. | Percent |
|---|---|---|
| Country | ||
| China (trials 1 and 2) | 90 | 57 |
| Vietnam (trial 3) | 68 | 43 |
| Profession | ||
| Doctors | 56 | 35·4 |
| Nurses | 102 | 64·6 |
| Age, years, mean (s.d.) | 32·8 (±9·14) | |
| Gender | ||
| Male | 21 | 13·3 |
| Female | 137 | 86·7 |
| Smoking status | ||
| Current/ex-smoker | 12 | 7·6 |
| No | 146 | 92·4 |
| Influenza vaccine | ||
| Yes | 22 | 13·9 |
| No | 136 | 86·1 |
| Virus type | ||
| Co-infection | 15 | 9·5 |
| Human rhinovirus | 75 | 47·5 |
| Respiratory syncytial virus | 28 | 17·7 |
| Influenza A and B viruses | 13 | 8·2 |
| Other* | 27 | 17·1 |
| Fever | ||
| Yes | 37 | 23·4 |
| No | 121 | 76·6 |
* Other includes: parainfluenza virus (n = 12), human metapneumovirus (n = 7), coronavirus (n = 7) and adenovirus (n = 1).