title: Low vaccine effectiveness against influenza A(H3N2) virus among elderly people in Denmark in 2012/13--a rapid epidemiological and virological assessment.
abstract: In Denmark, the 2012/13 influenza season has been dominated by influenza A(H3N2). We estimated the vaccine effectiveness (VE) of the trivalent influenza vaccine by linking national registers in a test-negative case-control study of patients tested for influenza aged ≥65 years. The adjusted VE against laboratory-confirmed influenza A and B was -11% (95% CI: -41 to 14) and 69% (95% CI: 26 to 87), respectively. Genetic characterisation of the influenza A(H3N2) viruses indicated genetic drift, with seven substitutions at key antigenic sites.
authors: National Influenza Centre, Department of Microbiological Diagnostics and Virology, Statens Serum Institut, Copenhagen.
authors: K
authors: K
authors: Bragstad
authors: Hd
authors: H
authors: Emborg
authors: T K
authors: TK
authors: Fischer
authors: M
authors: M
authors: Voldstedlund
authors: S
authors: S
authors: Gubbels
authors: B
authors: B
authors: Andersen
authors: K
authors: K
authors: Molbak
authors: Tg
authors: T
authors: Krause
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology*; D008297:Male; D017063:Outcome Assessment, Health Care; D011159:Population Surveillance; D012367:RNA, Viral / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017678:Sex Distribution
chemical_list: D007252:Influenza Vaccines; D012367:RNA, Viral