title: Vaccine effectiveness against severe laboratory-confirmed influenza in children: results of two consecutive seasons in Italy.
abstract: OBJECTIVE
  To evaluate the effectiveness of seasonal influenza vaccine in preventing Emergency Department (ED) visits and hospitalisations for influenza like illness (ILI) in children.
  
  
  METHODS
  We conducted a test negative case-control study during the 2011-2012 and 2012-2013 influenza seasons. Eleven paediatric hospital/wards in seven Italian regions participated in the study. Consecutive children visiting the ED with an ILI, as diagnosed by the doctor according to the European Centre for Disease Control case definition, were eligible for the study. Data were collected from trained pharmacists/physicians by interviewing parents during the ED visit (or hospital admission) of their children. An influenza microbiological test (RT-PCR) was carried out in all children.
  
  
  RESULTS
  Seven-hundred and four children, from 6 months to 16 years of age, were enrolled: 262 children tested positive for one of the influenza viruses (cases) and 442 tested negative (controls). Cases were older than controls (median age 46 vs. 29 months), though with a similar prevalence of chronic conditions. Only 25 children (4%) were vaccinated in the study period. The overall age-adjusted vaccine effectiveness (VE) was 38% (95% confidence interval -52% to 75%). A higher VE was estimated for hospitalised children (53%; 95% confidence interval -45% to 85%).
  
  
  CONCLUSIONS
  This study supports the effectiveness of the seasonal influenza vaccine in preventing visits to the EDs and hospitalisations for ILI in children, although the estimates were not statistically significant and with wide confidence intervals. Future systematic reviews of available data will provide more robust evidence for recommending influenza vaccination in children.
authors: National Centre of Epidemiology, National Institute of Health, Roma, Italy. Electronic address: francesca.menniti@iss.it.
authors: Francesca
authors: F
authors: Menniti-Ippolito
authors: National Centre of Epidemiology, National Institute of Health, Roma, Italy.
authors: Roberto
authors: R
authors: Da Cas
authors: National Centre of Epidemiology, National Institute of Health, Roma, Italy.
authors: Giuseppe
authors: G
authors: Traversa
authors: Italian Medicines Agency, Roma, Italy.
authors: Carmela
authors: C
authors: Santuccio
authors: Italian Medicines Agency, Roma, Italy.
authors: Patrizia
authors: P
authors: Felicetti
authors: Italian Medicines Agency, Roma, Italy.
authors: Loriana
authors: L
authors: Tartaglia
authors: Italian Medicines Agency, Roma, Italy.
authors: Francesco
authors: F
authors: Trotta
authors: Giannina Gaslini Paediatric Hospital, Genova, Italy.
authors: Pasquale
authors: P
authors: Di Pietro
authors: Giannina Gaslini Paediatric Hospital, Genova, Italy.
authors: Paola
authors: P
authors: Barabino
authors: Giannina Gaslini Paediatric Hospital, Genova, Italy.
authors: Salvatore
authors: S
authors: Renna
authors: Giannina Gaslini Paediatric Hospital, Genova, Italy.
authors: Laura
authors: L
authors: Riceputi
authors: Regina Margherita Paediatric Hospital, Torino, Italy.
authors: Pier-Angelo
authors: PA
authors: Tovo
authors: Regina Margherita Paediatric Hospital, Torino, Italy.
authors: Clara
authors: C
authors: Gabiano
authors: Regina Margherita Paediatric Hospital, Torino, Italy.
authors: Antonio
authors: A
authors: Urbino
authors: Regina Margherita Paediatric Hospital, Torino, Italy.
authors: Luca
authors: L
authors: Baroero
authors: Regina Margherita Paediatric Hospital, Torino, Italy.
authors: Daniele
authors: D
authors: Le Serre
authors: Regina Margherita Paediatric Hospital, Torino, Italy.
authors: Silvia
authors: S
authors: Virano
authors: Department of Paediatrics, University of Padova, Italy.
authors: Giorgio
authors: G
authors: Perilongo
authors: Department of Paediatrics, University of Padova, Italy.
authors: Marco
authors: M
authors: Daverio
authors: Department of Paediatrics, University of Padova, Italy.
authors: Elisa
authors: E
authors: Gnoato
authors: Department of Paediatrics, University of Padova, Italy.
authors: Michela
authors: M
authors: Maretti
authors: Department of Paediatrics, University of Padova, Italy.
authors: Beatrice
authors: B
authors: Galeazzo
authors: Department of Paediatrics, University of Padova, Italy.
authors: Giulia
authors: G
authors: Rubin
authors: Department of Paediatrics, University of Padova, Italy.
authors: Stefania
authors: S
authors: Scanferla
authors: Department of Paediatrics, Treviso Hospital, Treviso, Italy.
authors: Liviana
authors: L
authors: Da Dalt
authors: Department of Paediatrics, Treviso Hospital, Treviso, Italy.
authors: Chiara
authors: C
authors: Stefani
authors: Department of Paediatrics, Treviso Hospital, Treviso, Italy.
authors: Claudia
authors: C
authors: Zerbinati
authors: Anna Meyer Children's University Hospital, Firenze, Italy.
authors: Elena
authors: E
authors: Chiappini
authors: Anna Meyer Children's University Hospital, Firenze, Italy.
authors: Sara
authors: S
authors: Sollai
authors: Anna Meyer Children's University Hospital, Firenze, Italy.
authors: Maurizio
authors: M
authors: De Martino
authors: Anna Meyer Children's University Hospital, Firenze, Italy.
authors: Francesco
authors: F
authors: Mannelli
authors: Anna Meyer Children's University Hospital, Firenze, Italy.
authors: Sabrina
authors: S
authors: Becciani
authors: Anna Meyer Children's University Hospital, Firenze, Italy.
authors: Martina
authors: M
authors: Giacalone
authors: Anna Meyer Children's University Hospital, Firenze, Italy.
authors: Simona
authors: S
authors: Montano
authors: Anna Meyer Children's University Hospital, Firenze, Italy.
authors: Giulia
authors: G
authors: Remaschi
authors: Anna Meyer Children's University Hospital, Firenze, Italy.
authors: Alessia
authors: A
authors: Stival
authors: Department of Paediatrics, University Hospital, Perugia, Italy.
authors: Mario
authors: M
authors: Furbetta
authors: Department of Paediatrics, University Hospital, Perugia, Italy.
authors: Piera
authors: P
authors: Abate
authors: Department of Paediatrics, University Hospital, Perugia, Italy.
authors: Ilaria
authors: I
authors: Leonardi
authors: Emergency Department and Virology Unit, Bambino Gesù Children Hospital, Roma, Italy.
authors: Nicola
authors: N
authors: Pirozzi
authors: Emergency Department and Virology Unit, Bambino Gesù Children Hospital, Roma, Italy.
authors: Umberto
authors: U
authors: Raucci
authors: Emergency Department and Virology Unit, Bambino Gesù Children Hospital, Roma, Italy.
authors: Antonino
authors: A
authors: Reale
authors: Emergency Department and Virology Unit, Bambino Gesù Children Hospital, Roma, Italy.
authors: Rossella
authors: R
authors: Rossi
authors: Emergency Department and Virology Unit, Bambino Gesù Children Hospital, Roma, Italy.
authors: Cristina
authors: C
authors: Russo
authors: Emergency Department and Virology Unit, Bambino Gesù Children Hospital, Roma, Italy.
authors: Livia
authors: L
authors: Mancinelli
authors: Emergency Department and Virology Unit, Bambino Gesù Children Hospital, Roma, Italy.
authors: Onori
authors: O
authors: Manuela
authors: Emergency Department and Virology Unit, Bambino Gesù Children Hospital, Roma, Italy.
authors: Concato
authors: C
authors: Carlo
authors: Pharmacology, Microbiology and Virology, Università Cattolica S. Cuore, Roma, Italy.
authors: Nadia
authors: N
authors: Mores
authors: Pharmacology, Microbiology and Virology, Università Cattolica S. Cuore, Roma, Italy.
authors: Costantino
authors: C
authors: Romagnoli
authors: Pharmacology, Microbiology and Virology, Università Cattolica S. Cuore, Roma, Italy.
authors: Antonio
authors: A
authors: Chiaretti
authors: Pharmacology, Microbiology and Virology, Università Cattolica S. Cuore, Roma, Italy.
authors: Adele
authors: A
authors: Compagnone
authors: Pharmacology, Microbiology and Virology, Università Cattolica S. Cuore, Roma, Italy.
authors: Riccardo
authors: R
authors: Riccardi
authors: Pharmacology, Microbiology and Virology, Università Cattolica S. Cuore, Roma, Italy.
authors: Giovanni
authors: G
authors: Delogu
authors: Pharmacology, Microbiology and Virology, Università Cattolica S. Cuore, Roma, Italy.
authors: Michela
authors: M
authors: Sali
authors: Pharmacology, Microbiology and Virology, Università Cattolica S. Cuore, Roma, Italy.
authors: Valentina
authors: V
authors: Prete
authors: Santobono Paediatric Hospital and Virology Unit-Cotugno, Napoli, Italy.
authors: Vincenzo
authors: V
authors: Tipo
authors: Santobono Paediatric Hospital and Virology Unit-Cotugno, Napoli, Italy.
authors: Michele
authors: M
authors: Dinardo
authors: Santobono Paediatric Hospital and Virology Unit-Cotugno, Napoli, Italy.
authors: Fabiana
authors: F
authors: Auricchio
authors: Santobono Paediatric Hospital and Virology Unit-Cotugno, Napoli, Italy.
authors: Teodoro
authors: T
authors: Polimeno
authors: Santobono Paediatric Hospital and Virology Unit-Cotugno, Napoli, Italy.
authors: Giuseppe
authors: G
authors: Sodano
authors: Department of Experimental Medicine, Second University, Napoli, Italy.
authors: Alessandra
authors: A
authors: Maccariello
authors: Department of Experimental Medicine, Second University, Napoli, Italy.
authors: Concita
authors: C
authors: Rafaniello
authors: Giovanni Di Cristina Paediatric Hospital, Palermo, Italy.
authors: Fortunata
authors: F
authors: Fucà
authors: Giovanni Di Cristina Paediatric Hospital, Palermo, Italy.
authors: Eleonora
authors: E
authors: Di Rosa
authors: Department of Paediatric, Gynecologic, Microbiologic and Biomedical Sciences, University Hospital, Messina, Italy.
authors: Domenica
authors: D
authors: Altavilla
authors: Department of Paediatric, Gynecologic, Microbiologic and Biomedical Sciences, University Hospital, Messina, Italy.
authors: Anna
authors: A
authors: Mecchio
authors: Department of Paediatric, Gynecologic, Microbiologic and Biomedical Sciences, University Hospital, Messina, Italy.
authors: Teresa
authors: T
authors: Arrigo
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004632:Emergency Medical Services / Q000706:statistics & numerical data; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D007251:Influenza, Human / Q000473:pathology* / Q000517:prevention & control*; D007558:Italy / Q000453:epidemiology; D008297:Male; D016896:Treatment Outcome
chemical_list: D007252:Influenza Vaccines
keywords: Case-control study; Children; Influenza vaccine effectiveness; Laboratory-confirmed cases