title: Estimating influenza vaccine effectiveness in Spain using sentinel surveillance data.
abstract: We aimed to estimate influenza vaccine effectiveness (VE) against laboratory-confirmed influenza during three influenza seasons (2010/11 to 2012/2013) in Spain using surveillance data and to compare the results with data obtained by the cycEVA study, the Spanish component of the Influenza Monitoring Vaccine Effectiveness (I-MOVE) network. We used the test-negative case–control design, with data from the Spanish Influenza Sentinel Surveillance System (SISS) or from the cycEVA study. Cases were laboratory-confirmed influenza patients with the predominant influenza virus of each season, and controls were those testing negative for any influenza virus. We calculated the overall and age-specific adjusted VE. Although the number of patients recorded in the SISS was three times higher than that in the cycEVA study, the quality of information for important variables, i.e. vaccination status and laboratory results, was high in both studies. Overall, the SISS and cycEVA influenza VE estimates were largely similar during the study period. For elderly patients (> 59 years), the SISS estimates were slightly lower than those of cycEVA, and estimates for children (0–14 years) were higher using SISS in two of the three seasons studied. Enhancing the SISS by collecting the date of influenza vaccination and reducing the percentage of patients with incomplete information would optimise the system to provide reliable annual influenza VE estimates to guide influenza vaccination policies.
authors.affiliation: National Centre of Epidemiology, Institute of Health Carlos III, Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Jimenez-Jorge
authors.forename: S
authors.initials: S
authors.lastname: de Mateo
authors.forename: C
authors.initials: C
authors.lastname: Delgado-Sanz
authors.forename: F
authors.initials: F
authors.lastname: Pozo
authors.forename: I
authors.initials: I
authors.lastname: Casas
authors.forename: M
authors.initials: M
authors.lastname: Garcia-Cenoz
authors.forename: J
authors.initials: J
authors.lastname: Castilla
authors.forename: C
authors.initials: C
authors.lastname: Rodriguez
authors.forename: T
authors.initials: T
authors.lastname: Vega
authors.forename: C
authors.initials: C
authors.lastname: Quinones
authors.forename: E
authors.initials: E
authors.lastname: Martinez
authors.forename: J M
authors.initials: JM
authors.lastname: Vanrell
authors.forename: J
authors.initials: J
authors.lastname: Gimenez
authors.forename: D
authors.initials: D
authors.lastname: Castrillejo
authors.forename: J M
authors.initials: JM
authors.lastname: Altzibar
authors.forename: F
authors.initials: F
authors.lastname: Carril
authors.forename: J M
authors.initials: JM
authors.lastname: Ramos
authors.forename: M C
authors.initials: MC
authors.lastname: Serrano
authors.forename: A
authors.initials: A
authors.lastname: Martinez
authors.forename: N
authors.initials: N
authors.lastname: Torner
authors.forename: E
authors.initials: E
authors.lastname: Perez
authors.forename: V
authors.initials: V
authors.lastname: Gallardo
authors.forename: A
authors.initials: A
authors.lastname: Larrauri
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control* / Q000821:virology; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D018571:Sentinel Surveillance; D013030:Spain / Q000453:epidemiology; D014611:Vaccination / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines