Question: how effective is this year's flu vaccine uk?
Answer: Across all age groups including children, the flu vaccine prevented 15-52% of flu cases between 2015 - 2020 (see research by Public Health England on the effectiveness of flu vaccines in the 2015-16 season, 2016-17 season, 2017-18 season, 2018-19 season and 2019-20 season).