Interim 2018/19 influenza vaccine effectiveness: six European studies, October 2018 to January 2019 Kissling, Esther and Rose, Angela and Emborg, Hanne-Dorthe and Gherasim, Alin and Pebody, Richard and Pozo, Francisco and Trebbien, Ramona and Mazagatos, Clara and Whitaker, Heather and Valenciano, Marta and European IVE group, Eurosurveillance, 24, 1900121 (2019), https://doi.org/10.2807/1560-7917.ES.2019.24.1900121