Comparison of influenza vaccine effectiveness in preventing outpatient and inpatient influenza cases in older adults, northern Spain, 2010/11 to 2015/16 Castilla, Jesús and Martínez-Baz, Iván and Navascués, Ana and Casado, Itziar and Aguinaga, Aitziber and Díaz-González, Jorge and Delfrade, Josu and Guevara, Marcela and Ezpeleta, Carmen and Primary Health Care Sentinel Network of Navarre and Network for Influenza Surveillance in Hospitals of Navarre, Eurosurveillance, 23, 16-00780 (2018), https://doi.org/10.2807/1560-7917.ES.2018.23.2.16-00780