Table 1. Participants in negative-test case–control study of efficacy of seasonal influenza vaccine for preventing pandemic (H1N1) 2009, Australia, 2010.
| Participants | Age group, y |
Total, n = 319 | ||||
|---|---|---|---|---|---|---|
| 0–4, n = 19 | 5–19, n = 73 | 20–49, n = 181 | 50–64, n = 41 | >65, n = 5 | ||
| Controls | ||||||
| Total* | 13 (68) | 27 (37) | 107 (59) | 28 (68) | 5 (100) | 180 (56) |
| Vaccinated with monovalent vaccine† | 0 | 3 (11) | 7 (7) | 1 (4) | 0 | 11 (6) |
| Vaccinated with seasonal vaccine† | 0 | 0 | 9 (8) | 10 (36) | 2 (40) | 21 (12) |
| Vaccinated with both vaccines† |
0 |
0 |
7 (7) |
4 (14) |
2 (40) |
13 (7) |
| Pandemic (H1N1) 2009 case-patients | ||||||
| Total* | 6 (32) | 46 (63) | 74 (41) | 13 (32) | 0 | 139 (44) |
| Vaccinated with monovalent vaccine† | 0 | 3 (7) | 3 (4) | 0 | 0 | 6 (4) |
| Vaccinated with seasonal vaccine† | 0 | 2 (4) | 2 (3) | 0 | 0 | 4 (3) |
| Vaccinated with both vaccines† | 0 | 0 | 2 (3) | 0 | 0 | 2 (1) |
*No. (%) study participants. †No. (%) controls/pandemic (H1N1) 2009 case-patients.