1998/1999 | 1999/2000 | 2000/2001 | |
Excess deaths n | 547 (327–766) | 1019 (725–1313) | 206 (−76–488) |
HR | |||
Season | 0.56 (0.52–0.60) | 0.60 (0.56–0.65) | 0.63 (0.59–0.67) |
Off-season | 0.65 (0.60–0.70) | 0.75 (0.70–0.80) | 0.63 (0.59–0.68) |
Vaccine effectiveness# % | 14 (5–23) | 19 (11–27) | 1 (-10–11) |
NNT | 297 (212–495) | 158 (123–222) | 743 (314–∞) |
Predominant strain | Sydney H3N2 | Sydney H3N2 | B/A (H1N1) |
Antigenic match | Very good | Very good | Very good |
Start week¶ | 51 | 47 | 52 |
Peak week¶ | 7 | 52 | 10 |
End week¶ | 15 | 10 | 17 |
Influenza activity | Moderate | Moderate–high | Low |
Data are presented with 95% confidence intervals in parenthesis. #: based on comparison of fully adjusted HRs from the influenza seasons and following off-seasons; ¶: calendar week.