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Table 3 Circulation of influenza strains by region and season and attack rates

From: Epidemiology and burden of influenza in healthy children aged 6 to 35 months: analysis of data from the placebo arm of a phase III efficacy trial

Subtype/ lineage Confirmed influenza episodes, n (%)  
South Africa 2014 Philippines 2014 Philippines 2015 European countries a 2014/2015 European countries a 2015/2016 Total
N = 17 N = 93 N = 45 N = 37 N = 71 N = 263 Attack rate b, % (95% CI)
A(H1N1)  0 (0.0)  0 (0.0)  2 (4.4)  2 (5.4)  45 (63.4)  49 (18.6)  2.2 (1.6; 2.8)
A(H3N2)  16 (94.1)  23 (24.7)  43 (95.6)  24 (64.9)  1 (1.4)  107c (40.7)  4.6 (3.7; 5.5)
B/Yamagata  1 (5.9)  53 (57.0)  0 (0.0)  8 (21.6)  0 (0.0)  62 (23.6)  2.8 (2.1; 3.5)
B/Victoria  0 (0.0)  0 (0.0)  0 (0.0)  0 (0.0)  21 (26.9)  21 (8.0)  1.0 (0.5; 1.4)
Not subtyped  0 (0.0)  17 (18.3)  0 (0.0)  3 (8.1)  4 (5.6)  24 (9.1)  1.1 (0.7; 1.5)
  1. aFrance, Greece, Italy, Spain, and Romania
  2. bCalculated as the number of participants with at least one episode of confirmed influenza divided by the total number of participants (N = 2210)
  3. c107 episodes in 102 participants