Early estimates of the effectiveness of the 2011/12 influenza vaccine in the population targeted for vaccination in Spain, 25 December 2011 to 19 February 2012 Jiménez-Jorge, S and de Mateo, S and Pozo, F and Casas, I and García Cenoz, M and Castilla, J and Gallardo, V and Pérez, E and Vega, T and Rodriguez, C and Quiñones, C and Martínez, E and Giménez, J and Vanrell, J M and Castrillejo, D and Serrano, M C and Ramos, J M and Larrauri, A, Eurosurveillance, 17, 20129 (2012), https://doi.org/10.2807/ese.17.12.20129-en