US Flu VE Data for 2019-2020

Interim Estimates of 2019–20 Seasonal Influenza Vaccine Effectiveness — United States, February 2020

Description of patients enrolled in the US Flu VE Network, 2019-2020
Age
Age Number % Total
6 months-8 years 915 22
9-17 years 481 12
18-49 years 1497 36
50-64 years 645 16
65+ years 574 14
Sex
Sex Number % Total
Male 1646 40
Female 2466 60
Race/ethnicity
Race Number % Total
White, non-Hispanic 2860 70
Black, non-Hispanic 380 9
Hispanic 462 11
Other, non-Hispanic 402 10

Interim influenza vaccine effectiveness for all vaccine types

Interim 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 1060 390 (37) 3052 1682 (55) 45 (36, 53)
6 mos–17 751 (40) 1677 492 (53) 55 (42, 65)
18–49 413 143 (35) 1084 452 (42) 25 (3, 41)
≥50 185 105 (57) 1034 738 (71) 43 (19, 60)
Interim influenza vaccine effectiveness for all vaccine types, Influenza A(H1N1)pdm09 viruses
Age group (years) Influenza positive
Total
Influenza positive
(% Vaccinated)
Influenza negative
Total
Influenza negative
(% Vaccinated)
Adjusted VE % Adjusted 95% CI
All ages 326 138 (42) 3052 1682 (55) 37 (19, 52)
6 mos–17 98 35 (36) 934 492 (53) 51 (22, 69)
18–49 125 48 (38) 1084 452 (42) 5 (-45, 37)
≥50 103 55 (53) 1034 738 (71) 50 (20, 68)

 

Interim influenza vaccine effectiveness for all vaccine types, against influenza B/Victoria viruses
Age group (years) Influenza positive
Total
Influenza positive
(% Vaccinated)
Influenza negative
Total
Influenza negative
(% Vaccinated)
Adjusted VE % Adjusted 95% CI
All ages 634 211 (33) 2968 1641 (55) 50 (39, 59)
6 mos – 17 353 104 (29) 934 492 (53) 56 (42, 67)
≥18 317 117 (37) 2118 1190 (56) 32 (11, 48)

 

Influenza virus type and subtype among influenza-positive patients, US Flu VE Network, 2019-2020
Virus Type Number % Total
Influenza A 374 35
H3N2 11 1
H1N1pdm09 326 31
A, Not subtyped 39 4
Influenza B 691 65
B Yamagata 3 <1
B Victoria 670 63
Lineage not determined 18 2

** Flannery, et al, 2019