RT Journal Article SR Electronic(1) A1 Baum, Ulrike A1 Kulathinal, Sangita A1 Auranen, Kari YR 2021 T1 Spotlight influenza: Estimation of influenza vaccine effectiveness in elderly people with assessment of residual confounding by negative control outcomes, Finland, 2012/13 to 2019/20 JF Eurosurveillance VO 26 IS 36 SP 2100054 OP DO https://doi.org/10.2807/1560-7917.ES.2021.26.36.2100054 UL https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2021.26.36.2100054