title: Effectiveness of Trivalent Inactivated Influenza Vaccine in Children Estimated by a Test-Negative Case-Control Design Study Based on Influenza Rapid Diagnostic Test Results.
abstract: We assessed vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza in children 6 months to 15 years of age in 22 hospitals in Japan during the 2013-14 season. Our study was conducted according to a test-negative case-control design based on influenza rapid diagnostic test (IRDT) results. Outpatients who came to our clinics with a fever of 38 °C or over and had undergone an IRDT were enrolled in this study. Patients with positive IRDT results were recorded as cases, and patients with negative results were recorded as controls. Between November 2013 and March 2014, a total of 4727 pediatric patients (6 months to 15 years of age) were enrolled: 876 were positive for influenza A, 66 for A(H1N1)pdm09 and in the other 810 the subtype was unknown; 1405 were positive for influenza B; and 2445 were negative for influenza. Overall VE was 46% (95% confidence interval [CI], 39-52). Adjusted VE against influenza A, influenza A(H1N1)pdm09, and influenza B was 63% (95% CI, 56-69), 77% (95% CI, 59-87), and 26% (95% CI, 14-36), respectively. Influenza vaccine was not effective against either influenza A or influenza B in infants 6 to 11 months of age. Two doses of influenza vaccine provided better protection against influenza A infection than a single dose did. VE against hospitalization influenza A infection was 76%. Influenza vaccine was effective against influenza A, especially against influenza A(H1N1)pdm09, but was much less effective against influenza B.
authors: Department of Pediatrics, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; Center for Infectious Diseases and Infection Control, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.
authors: Masayoshi
authors: M
authors: Shinjoh
authors: Department of Paediatrics, Keiyu Hospital, Yokohama, Kanagawa, Japan.
authors: Norio
authors: N
authors: Sugaya
authors: Department of Clinical Research, National Hospital Organization, Utsunomiya, Tochigi Medical Center, Tochigi, Japan.
authors: Yoshio
authors: Y
authors: Yamaguchi
authors: Department of Pediatrics, Tokyo Metropolitan Ohtsuka Hospital, Toshima-ku, Tokyo, Japan.
authors: Yuka
authors: Y
authors: Tomidokoro
authors: Department of Pediatrics, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.
authors: Shinichiro
authors: S
authors: Sekiguchi
authors: Department of Pediatrics, Eiju General Hospital, Taito-ku, Tokyo, Japan.
authors: Keiko
authors: K
authors: Mitamura
authors: Department of Pediatrics, Saiseikai Central Hospital, Minato-ku, Tokyo, Japan.
authors: Motoko
authors: M
authors: Fujino
authors: Department of Pediatrics, Yokohama Rosai Hospital, Yokohama, Kanagawa, Japan.
authors: Hiroyuki
authors: H
authors: Shiro
authors: Department of Pediatrics, National Hospital Organization, Tokyo Medical Center, Meguro-ku, Tokyo, Japan.
authors: Osamu
authors: O
authors: Komiyama
authors: Department of Paediatrics, Keiyu Hospital, Yokohama, Kanagawa, Japan.
authors: Nobuhiko
authors: N
authors: Taguchi
authors: Department of Pediatrics, Nippon Kokan Hospital, Kawasaki, Kanagawa, Japan.
authors: Yuji
authors: Y
authors: Nakata
authors: Department of Pediatrics, Kyosai Tachikawa Hospital, Tachikawa, Tokyo, Japan.
authors: Naoko
authors: N
authors: Yoshida
authors: Department of Paediatrics, Kawasaki Municipal Hospital, Kawasaki, Kanagawa, Japan.
authors: Atsushi
authors: A
authors: Narabayashi
authors: Department of Pediatrics, Shizuoka City Shimizu Hospital, Shizuoka, Shizuoka, Japan.
authors: Michiko
authors: M
authors: Myokai
authors: Department of Pediatrics, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Chiba, Japan.
authors: Masanori
authors: M
authors: Sato
authors: Department of Pediatrics, Saitama City Hospital, Saitama, Saitama, Japan.
authors: Munehiro
authors: M
authors: Furuichi
authors: Department of Pediatrics, Fuji Heavy Industries Health Insurance Society Ota Memorial Hospital, Ota, Gunma, Japan.
authors: Hiroaki
authors: H
authors: Baba
authors: Department of Pediatrics, Hiratsuka Kyosai Hospital, Hiratsuka, Kanagawa, Japan.
authors: Hisayo
authors: H
authors: Fujita
authors: Department of Pediatrics, Yokohama Municipal Citizen's hospital, Yokohama, Kanagawa, Japan.
authors: Akihiro
authors: A
authors: Sato
authors: Department of Pediatrics, Japanese Red Cross Shizuoka Hospital, Shizuoka, Shizuoka, Japan.
authors: Ichiro
authors: I
authors: Ookawara
authors: Department of Pediatrics, Hino Municipal Hospital, Hino, Tokyo, Japan.
authors: Kenichiro
authors: K
authors: Tsunematsu
authors: Department of Pediatrics, Sano Kousei General Hospital, Sano, Tochigi, Japan.
authors: Makoto
authors: M
authors: Yoshida
authors: Department of Pediatrics, National Hospital Organization Saitama National Hospital, Wako, Saitama, Japan.
authors: Mio
authors: M
authors: Kono
authors: Department of Pediatrics, Hiratsuka City Hospital, Hiratsuka, Kanagawa, Japan.
authors: Fumie
authors: F
authors: Tanaka
authors: Yokohama City Institute of Health, Yokohama, Kanagawa, Japan.
authors: Chiharu
authors: C
authors: Kawakami
authors: Department of Pediatrics, Tokyo Metropolitan Ohtsuka Hospital, Toshima-ku, Tokyo, Japan.
authors: Takahisa
authors: T
authors: Kimiya
authors: Department of Pediatrics, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.
authors: Takao
authors: T
authors: Takahashi
authors: Center for Infectious Diseases and Infection Control, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; Department of Infectious Diseases, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.
authors: Satoshi
authors: S
authors: Iwata
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D009981:Influenza B virus / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology; D007251:Influenza, Human / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control*; D008297:Male
chemical_list: D007252:Influenza Vaccines