The annual seasonal influenza risk assessments by ECDC are designed to provide an early description of the epidemiological pattern of seasonal influenza each year and to predict the evolution of influenza activity for the remaining part of each season.
Each seasonal risk assessment is based on clinical, epidemiological and virological data that is routinely reported to ECDC, as well as, among other things, responses to a short questionnaire on the impact of influenza in the first-affected countries. Lessons learned from previous seasons are also taken into consideration in the compilation of each new seasonal risk assessment.
Each document is published while the influenza season is ongoing and as a result the risk assessment remains under review until the season is over. Updates may be made later in the season if deemed necessary.