Seasonal Influenza Vaccine Effectiveness, 2014-2015

Table. Description of patients by Age
Age Number % Total
6 months-8 years 2,419 26
9-17 years 1,342 14
18-49 years 2,848 31
50-64 years 1,496 16
65+ years 1,206 13
Table. Description of patients by Gender
Gender Number % Total
Male 3,923 42
Female 5,288 58
Table. Description of patients by Race/ethnicity
Race Number % Total
White, non-Hispanic 6,888 74
Black, non-Hispanic 688 7
Hispanic 840 9
Other, non-Hispanic 872 9
Table. Influenza virus type and subtype among influenza-positive patients
Virus Type Number % Total
Influenza A 1,840 82
H3N2 1,817 81
H1N1 4 <1
Not subtyped 19 <1
Influenza B 395 18
B Yamagata 340 15
B Victoria 47 2
Lineage not determined 8 <1

Coinfections present include: 5 cases coinfected with Influenza A (H3N2) and Influenza B Yamagata; 1 case coinfected with Influenza A (H3N2) and Influenza B Yamagata (lineage not determined); 1 case coinfected with Influenza A (not subtyped) and Influenza B Yamagata; 3 cases coinfected with Influenza B Yamagata and Influenza B/Victoria

Table. Influenza vaccine effectiveness for all vaccine types, against influenza A or B viruses
Age group (years) Influenza positive
Total
Influenza positive
(% Vaccinated)
Influenza negative
Total
Influenza negative
(% Vaccinated)
Adjusted VE % Adjusted 95% CI
All ages 2,233 -49 7,078 -55 19% (10 to 27)
6 mos–8 473 -39 1,946 -52 25% (6 to 40)
9–17 392 -35 950 -41 25% (2 to 42)
18–49 642 -42 2,206 -45 7% (-12 to 33)
50–64 378 -61 1,118 -66 20% (-3 to 38)
≥65 348 -79 858 -85 32% (3 to 52)
Table. Influenza vaccine effectiveness for all vaccine types, against Influenza A (H3N2) viruses
Age group (years) Influenza positive Total Influenza positive (% Vaccinated) Influenza negative Total Influenza negative (% Vaccinated) Adjusted VE % Adjusted 95% CI
All ages 1,817 -52 7,078 -55 6% (-5 to 17)
6 mos–8 396 -40 1,946 -52 20% (-3 to 37)
9–17 306 -39 950 -41 7% (-26 to 31)
18–49 531 -44 2,206 -45 -6% (-31 to 24)
50–64 281 -63 1,118 -66 12% (-19 to 34)
≥65 303 -82 858 -85 12% (-29 to 40)
Table. Influenza vaccine effectiveness for all vaccine types, against Influenza B/Yamagata lineage viruses
Age group (years) Influenza positive Total Influenza positive (% Vaccinated) Influenza negative Total Influenza negative (% Vaccinated) Adjusted VE % Adjusted 95% CI
All ages 340 -38 7,078 -55 55% (43 to 65)
6 mos–8 60 -30 1,946 -52 54% (17 to 74)
9–17 60 -15 950 -41 77% (51 to 89)
18–49 90 -29 2,206 -45 55% (27 to 73)
50–64 90 -58 1,118 -66 24% (-20 to 52)
≥65 40 -58 858 -85 74% (45 to 87)
Table. Influenza vaccine effectiveness for Live Attenuated Influenza Vaccines in children, against influenza A or B viruses
Age group (years) Influenza positive Total Influenza positive (% Vaccinated) Influenza negative Total Influenza negative (% Vaccinated) Adjusted VE % Adjusted 95% CI
A H3N2
2-17 490 -20 1,682 -22 -5% (-40 to 21)
B Yamagata
2-17 98 -6 1,682 -22 76% (43 to 90)
Table. Influenza vaccine effectiveness for Inactivated Influenza Vaccine in children, against influenza A or B viruses
Age group (years) Influenza positive Total Influenza positive (% Vaccinated) Influenza negative Total Influenza negative (% Vaccinated) Adjusted VE % Adjusted 95% CI
A H3N2
2-17 554 -29 2,067 -36 13% (-10 to 30)
B Yamagata
2-17 108 -16 2,067 -32 66% (41 to 80)