Table 7. Effectiveness of seasonal influenza vaccine against influenza-like illness, New South Wales, Australia, July–September 2009*.

Subgroup, n = 2,888	Vaccine effectiveness, % (95% CI)†
Age, y
0.5–15	6.1 (−120.1 to 60.0)
16–34	44.6 (−166.8 to 88.5)
35–49	−0.9 (−137.2 to 57.1)
50–64	33.7 (−69.7 to 74.1)
>65	−97.9 (−622.5 to 45.8)
Sex†
M	34.5 (−71.7 to 75.0)
F	10.5 (−49.2 to 46.4)
Region†
Urban	17.1 (−55.7 to 55.9)
Rural	25.5 (−49.7 to 62.9)
Smoking status†
Daily smoker	1.4 (−175.3 to 64.7)
Not daily smoker	22.3 (−53.2 to 60.6)
Body mass index†
Obese	25.0 (−81.6 to 69.1)
Not obese	9.2 (−66.0 to 50.4)
Overall†	20.0 (−30.5 to 51.0)
*For persons >6 mo of age vaccinated in past 12 mo. CI, confidence interval. †Adjusted for age.