title: Vaccine effectiveness against medically attended laboratory-confirmed influenza in Japan, 2011-2012 Season.
abstract: The objective of this study was to estimate influenza vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza during the 2011-2012 season in Japan using a test-negative case-control study design. The effect of co-circulating non-influenza respiratory viruses (NIRVs) on VE estimates was also explored. Nasopharyngeal swab samples were collected from outpatients with influenza-like illnesses (ILIs) in a community hospital in Nagasaki, Japan. Thirteen respiratory viruses (RVs), including influenza A and B, were identified from the samples using a multiplex polymerase chain reaction. The difference in VE point estimates was assessed using three different controls: ILI patients that tested negative for influenza, those that tested negative for all RVs, and those that tested positive for NIRVs. The adjusted VE against medically attended, laboratory-confirmed influenza using all influenza-negative controls was 5.3% (95% confidence interval [CI], -60.5 to 44.1). The adjusted VEs using RV-negative and NIRV-positive controls were -1.5% (95% CI, -74.7 to 41) and 50% (95% CI, -43.2 to 82.5), respectively. Influenza VE was limited in Japan during the 2011-2012 season. Although the evidence is not conclusive, co-circulating NIRVs may affect influenza VE estimates in test-negative case-control studies.
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Motoi
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Le Nhat
authors.initials: le N
authors.lastname: Minh
authors.affiliation: Inoue Hospital, Shunkaikai, Nagasaki, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshimine
authors.affiliation: Inoue Hospital, Shunkaikai, Nagasaki, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Inoue
authors.affiliation: Department of Paediatric Infectious Diseases, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Lay Myint
authors.initials: LM
authors.lastname: Yoshida
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Konosuke
authors.initials: K
authors.lastname: Morimoto
authors.affiliation: Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: Koya
authors.initials: K
authors.lastname: Ariyoshi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology / Q000302:isolation & purification; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology / Q000302:isolation & purification; D009981:Influenza B virus / Q000276:immunology / Q000302:isolation & purification; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000175:diagnosis / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D007564:Japan; D008297:Male; D008875:Middle Aged; D010850:Picornaviridae Infections / Q000175:diagnosis / Q000276:immunology / Q000821:virology; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis / Q000276:immunology / Q000821:virology; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology / Q000302:isolation & purification; D012229:Rhinovirus / Q000276:immunology / Q000302:isolation & purification; D012621:Seasons; D016896:Treatment Outcome; D014611:Vaccination
chemical_list: D007252:Influenza Vaccines