Skip to main content

Table 4 Vaccine effectiveness (VE) of TIV against influenza-related hospitalization in patients ≥16–64 years (younger adults group)

From: Influenza vaccine effectiveness against influenza-related hospitalization during a season with mixed outbreaks of four influenza viruses: a test-negative case-control study in adults in Canada

 

Cases

Controls

Unadjusted

Adjusted

 

N

N

VE, %

95% CI

VE, %

95% CI

All strains

208

271

35.8

4.5, 56.8

33.2a

−6.7, 58.2

Influenza A

86

110

48.5

1.4, 73.1

42.2b

−24.2, 73.1

 A/H1N1

55

68

57.8

2.7, 81.7

68.7c

6.4, 89.5

 A/H3N2

13

18

38.2

−599.5, 94.5

Influenza B

122

161

26.2

−22.2, 55.4

25.4d

−35.4, 58.9

 B/Victoria

37

48

25.6

−82.8, 69.7

9.7e

−161.6, 68.9

 B/Yamagata

53

70

16.6

−81.1, 61.6

36.9f

−72.5, 76.9

  1. N number of patients, CI Confidence Interval, TIV trivalent influenza vaccine, VE vaccine effectiveness
  2. Covariate (p-value in model):
  3. a Influenza vaccination (0.092), age (0.018), anti-viral use before admission (0.881), seniors including patient living in dwelling (0.020), pregnancy (0.045);
  4. b Influenza vaccination (0.160), age (0.192), anti-viral use before admission (0.874) seniors including patient living in dwelling (0.188), pregnancy (0.991);
  5. c Influenza vaccination (0.038), age (0.173), anti-viral use before admission (0.895) seniors including patient living in dwelling (0.201), pregnancy (0.994);
  6. d Influenza vaccination (0.335), age (0.045), seniors including patient living in dwelling (0.046), pregnancy (0.099);
  7. e Influenza vaccination (0.850), age (0.054), seniors including patient living in dwelling (0.888), pregnancy (0.996);
  8. f Influenza vaccination (0.370), age (0.783), seniors including patient living in dwelling (0.037), pregnancy (0.740)