F. Lameiro, A. Navascués, E. M. García-orcoyen, M. Ortega, J. Torres et al., Hospital Reina Sofía, Tudela. Fátima Irisarri, Manuel García Cenoz and Iván Martínez-Baz

F. Carrat and A. Flahault, Influenza vaccine: the challenge of antigenic drift, Vaccine, vol.25, p.17719149, 2007.

, Influenza vaccines, Wkly Epidemiol Rec, vol.80, issue.33, p.16171031, 2005.

, Note for guidance on harmonization of requirements for influenza vaccines

L. Coudeville, F. Bailleux, B. Riche, F. Megas, P. Andre et al., Relationship between haemagglutination-inhibiting antibody titres and clinical protection against influenza: development and application of a bayesian random-effects model, BMC Med Res Methodol, vol.10, issue.1, p.20210985, 2010.

J. A. Mccullers and V. C. Huber, Correlates of vaccine protection from influenza and its complications, Hum Vaccin Immunother, vol.8, issue.1, p.22252001, 2012.

, World Health Organiation (WHO) Strategic Advisory Group of Experts on immunization (SAGE), SAGE Working Group. Geneva: WHO, 2012.

J. Mereckiene, S. Cotter, D. 'ancona, F. Giambi, C. Nicoll et al., VENICE project gatekeepers group. Differences in national influenza vaccination policies across the European Union, Norway and Iceland, Euro Surveill, vol.15, issue.44, 2008.

, Recommended composition of influenza virus vaccines for use in the 2012-2013 northern hemisphere influenza season, 2012.

S. E. Ohmit, J. G. Petrie, R. E. Malosh, B. J. Cowling, M. G. Thompson et al., Influenza vaccine effectiveness in the community and the household, Clin Infect Dis, vol.56, issue.10, p.23413420, 2013.

S. E. Ohmit, M. G. Thompson, J. G. Petrie, S. N. Thaker, M. L. Jackson et al., Influenza vaccine effectiveness in the 2011-2012 season: protection against each circulating virus and the effect of prior vaccination on estimates, Clin Infect Dis, vol.58, issue.3, pp.319-346, 2014.

H. Mclean, M. Sundaram, B. Kieke, J. Meece, D. Mcclure et al., Current and previous season vaccination have similar effectiveness for preventing medically attended influenza A (H3N2) and B: results from a community cohort over 8 seasons. Poster presentation at Options for the control of Influenza VIII, pp.5-10, 2013.

M. Rondy, J. Puig-barbera, O. Launay, X. Duval, J. Castilla et al., 2011-12 seasonal influenza vaccines effectiveness against confirmed A(H3N2) influenza hospitalisation: pooled analysis from a European network of hospitals. A pilot study, PLoS ONE, vol.8, issue.4, p.23565159, 2013.

, European Centre for Disease Prevention and Control (ECDC), 2012.

M. Valenciano, E. Kissling, B. C. Ciancio, and A. Moren, Study designs for timely estimation of influenza vaccine effectiveness using European sentinel practitioner networks, Vaccine, vol.28, issue.46, p.20851086, 2010.

T. Seyler, M. Rondy, M. Valenciano, and A. Moren, Protocol for hospital-based case control studies to measure seasonal influenza vaccine effectiveness against laboratory confirmed influenza hospitalisations across the European Union and European Economic Area Member States, 2014.

I. ,

. Haut-conseil-de-la-sante´publiquesante´publique, Le Calendrier des vaccinations et les recommandations vaccinales 2012 selon l'avis du Haut Conseil de la santé publique, Bulletin épidémiologique hebdomadaire, 2012.

. Ministero-della-salute, Prevenzione e controllo dell'influenza: raccomandazioni per la stagione 2012-2013. [Prevention and control of influenza: recommendations for the season, 2012.

R. , Ministero della Salute, 2012.

, Seasonal influenza vaccination survey in EU/ EEA, influenza season 2009-10. Final report. VENICE, Vaccine European New Integrated Collaboration Effort (VENICE) II Consortium, 2011.

, Protocolo de vacunacion antigripal, 2012.

, Boletin informative, vol.69, pp.1-4, 2012.

, Vacunacion antigripal estacional 2012

, Direccio General d'Investigacio i Salut Publica, Generalitat Vaclenciana

, ISO 8601:2004: Data elements and interchange formatsInformation interchange-Representation of dates and times, 2004.

F. I. Mahoney and D. W. Barthel, Functional evaluation: the Barthel index, Md State Med J, vol.14, p.14258950, 1965.

T. B. Huedo-medina, J. Sánchez-meca, F. Marín-martínez, and J. Botella, Assessing heterogeneity in meta-analysis: Q statistic or I2 index?, Psychol Methods, vol.11, issue.2, p.16784338, 2006.

T. A. Stukel, E. Demidenko, J. Dykes, and M. R. Karagas, Twostage methods for the analysis of pooled data, Stat Med, vol.20, issue.14, pp.2115-2145, 2001.

F. E. Harrell, Regression modeling strategies: with applications to linear models, logistic regression, and survival analysis, 2001.

I. M. Foppa, M. Haber, J. M. Ferdinands, and D. K. Shay, The case testnegative design for studies of the effectiveness of influenza vaccine, Vaccine, vol.31, issue.30, p.23624093, 2013.

M. L. Jackson and J. C. Nelson, The test-negative design for estimating influenza vaccine effectiveness, Vaccine, vol.31, issue.17, p.23499601, 2013.

E. W. Orenstein, D. Serres, G. Haber, M. J. Shay, D. K. Bridges et al., Methodologic issues regarding the use of three observational study designs to assess influenza vaccine effectiveness, Int J Epidemiol, vol.36, issue.3, p.17403908, 2007.

M. Petric, L. Comanor, and C. A. Petti, Role of the laboratory in diagnosis of influenza during seasonal epidemics and potential pandemics, J Infect Dis, vol.194, issue.s2, p.17163396, 2006.

, World Health Organization (WHO) Regional Office for Europe. In-patient care discharges per 100. European Health for All database (HFA-DB), 2014.

S. E. Ohmit, J. G. Petrie, R. E. Malosh, B. J. Cowling, M. G. Thompson et al., Influenza vaccine effectiveness in the community and the household, Clin Infect Dis, vol.56, issue.10, p.23413420, 2013.

J. R. Davies and E. A. Grilli, Natural or vaccine-induced antibody as a predictor of immunity in the face of natural challenge with influenza viruses, Epidemiol Infect, vol.102, issue.2, p.2703026, 1989.

D. J. Smith, S. Forrest, D. H. Ackley, and A. S. Perelson, Variable efficacy of repeated annual influenza vaccination, Proc Natl Acad Sci USA, vol.96, issue.24, p.10570188, 1999.

D. E. Karageorgopoulos, E. K. Vouloumanou, I. P. Korbila, A. Kapaskelis, and M. E. Falagas, Age distribution of cases of 2009 (H1N1) pandemic influenza in comparison with seasonal influenza, PLoS ONE, vol.6, issue.7, p.21747947, 2011.

S. Sasaki, X. He, T. H. Holmes, C. L. Dekker, G. W. Kemble et al., Influence of prior influenza vaccination on antibody and B-cell responses, PLoS ONE, vol.3, issue.8, p.18714352, 2008.

E. Kissling, M. Valenciano, A. Larrauri, B. Oroszi, J. M. Cohen et al., Low and decreasing vaccine effectiveness against influenza A(H3) in 2011/12 among vaccination target groups in Europe: results from the I-MOVE multicentre casecontrol study, Euro Surveill, vol.18, issue.5, 2013.

R. Pebody, N. Andrews, J. Mcmenamin, H. Durnall, J. Ellis et al., Vaccine effectiveness of 2011/12 trivalent seasonal influenza vaccine in preventing laboratoryconfirmed influenza in primary care in the United Kingdom: evidence of waning intra-seasonal protection, Euro Surveill, vol.18, issue.5, 2013.
URL : https://hal.archives-ouvertes.fr/hal-01261731

J. Castilla, I. Martínez-baz, V. Martínez-artola, R. G. Pozo, F. et al., Decline in influenza vaccine effectiveness with time after vaccination, Navarre, Spain, season 2011/12, Euro Surveill, vol.18, issue.5, 2013.