title: 2012/13 influenza vaccine effectiveness against hospitalised influenza A(H1N1)pdm09, A(H3N2) and B: estimates from a European network of hospitals.
abstract: While influenza vaccines aim to decrease the incidence of severe influenza among high-risk groups, evidence of influenza vaccine effectiveness (IVE) among the influenza vaccine target population is sparse. We conducted a multicentre test-negative case-control study to estimate IVE against hospitalised laboratory-confirmed influenza in the target population in 18 hospitals in France, Italy, Lithuania and the Navarre and Valencia regions in Spain. All hospitalised patients aged ≥18 years, belonging to the target population presenting with influenza-like illness symptom onset within seven days were swabbed. Patients positive by reverse transcription polymerase chain reaction for influenza virus were cases and those negative were controls. Using logistic regression, we calculated IVE for each influenza virus subtype and adjusted it for month of symptom onset, study site, age and chronic conditions. Of the 1,972 patients included, 116 were positive for influenza A(H1N1)pdm09, 58 for A(H3N2) and 232 for influenza B. Adjusted IVE was 21.3% (95% confidence interval (CI): -25.2 to 50.6; n=1,628), 61.8% (95% CI: 26.8 to 80.0; n=557) and 43.1% (95% CI: 21.2 to 58.9; n=1,526) against influenza A(H1N1) pdm09, A(H3N2) and B respectively. Our results suggest that the 2012/13 IVE was moderate against influenza A(H3N2) and B and low against influenza A(H1N1) pdm09.
authors.affiliation: EpiConcept, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Rondy
authors.forename: O
authors.initials: O
authors.lastname: Launay
authors.forename: J
authors.initials: J
authors.lastname: Puig-Barberà
authors.forename: G
authors.initials: G
authors.lastname: Gefenaite
authors.forename: J
authors.initials: J
authors.lastname: Castilla
authors.forename: K
authors.initials: K
authors.lastname: de Gaetano Donati
authors.forename: F
authors.initials: F
authors.lastname: Galtier
authors.forename: E
authors.initials: E
authors.lastname: Hak
authors.forename: M
authors.initials: M
authors.lastname: Guevara
authors.forename: S
authors.initials: S
authors.lastname: Costanzo
authors.forename: A
authors.initials: A
authors.lastname: Moren
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005060:Europe / Q000453:epidemiology; D005062:European Union; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; 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 / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012621:Seasons; D018571:Sentinel Surveillance; D016896:Treatment Outcome; D014611:Vaccination / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines