title: I-MOVE multi-centre case control study 2010-11: overall and stratified estimates of influenza vaccine effectiveness in Europe.
abstract: BACKGROUND
  In the third season of I-MOVE (Influenza Monitoring Vaccine Effectiveness in Europe), we undertook a multicentre case-control study based on sentinel practitioner surveillance networks in eight European Union (EU) member states to estimate 2010/11 influenza vaccine effectiveness (VE) against medically-attended influenza-like illness (ILI) laboratory-confirmed as influenza.
  
  
  METHODS
  Using systematic sampling, practitioners swabbed ILI/ARI patients within seven days of symptom onset. We compared influenza-positive to influenza laboratory-negative patients among those meeting the EU ILI case definition. A valid vaccination corresponded to > 14 days between receiving a dose of vaccine and symptom onset. We used multiple imputation with chained equations to estimate missing values. Using logistic regression with study as fixed effect we calculated influenza VE adjusting for potential confounders. We estimated influenza VE overall, by influenza type, age group and among the target group for vaccination.
  
  
  RESULTS
  We included 2019 cases and 2391 controls in the analysis. Adjusted VE was 52% (95% CI 30-67) overall (N = 4410), 55% (95% CI 29-72) against A(H1N1) and 50% (95% CI 14-71) against influenza B. Adjusted VE against all influenza subtypes was 66% (95% CI 15-86), 41% (95% CI -3-66) and 60% (95% CI 17-81) among those aged 0-14, 15-59 and ≥60 respectively. Among target groups for vaccination (N = 1004), VE was 56% (95% CI 34-71) overall, 59% (95% CI 32-75) against A(H1N1) and 63% (95% CI 31-81) against influenza B.
  
  
  CONCLUSIONS
  Results suggest moderate protection from 2010-11 trivalent influenza vaccines against medically-attended ILI laboratory-confirmed as influenza across Europe. Adjusted and stratified influenza VE estimates are possible with the large sample size of this multi-centre case-control. I-MOVE shows how a network can provide precise summary VE measures across Europe.
authors: EpiConcept, Paris, France. e.kissling@epiconcept.fr
authors: Esther
authors: E
authors: Kissling
authors: Marta
authors: M
authors: Valenciano
authors: Jean Marie
authors: JM
authors: Cohen
authors: Beatrix
authors: B
authors: Oroszi
authors: Anne-Sophie
authors: AS
authors: Barret
authors: Caterina
authors: C
authors: Rizzo
authors: Pawel
authors: P
authors: Stefanoff
authors: Baltazar
authors: B
authors: Nunes
authors: Daniela
authors: D
authors: Pitigoi
authors: Amparo
authors: A
authors: Larrauri
authors: Isabelle
authors: I
authors: Daviaud
authors: Judit Krisztina
authors: JK
authors: Horvath
authors: Joan
authors: J
authors: O'Donnell
authors: Thomas
authors: T
authors: Seyler
authors: Iwona Anna
authors: IA
authors: Paradowska-Stankiewicz
authors: Pedro
authors: P
authors: Pechirra
authors: Alina Elena
authors: AE
authors: Ivanciuc
authors: Silvia
authors: S
authors: Jiménez-Jorge
authors: Camelia
authors: C
authors: Savulescu
authors: Bruno Christian
authors: BC
authors: Ciancio
authors: Alain
authors: A
authors: Moren
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005060:Europe; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology / Q000472:pathogenicity; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D012621:Seasons; D013045:Species Specificity; D013997:Time Factors; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines