Influenza viruses cause acute respiratory disease, also known as flu. Annually, the virus causes
; epidemics, which has a huge impact on the health care systems and the economic.
; Surveillance of influenza viruses is coordinated at a global level by WHO (World Health Organisation)
; through the GISRS (Global Influenza Surveillance and Response System) network implemented in
; 1952. The network is organised with reference national laboratories in several countries (National
; Influenza Centres), regional supranational organisations (such as ECDC, European Centre for Disease
; Control and prevention, in the European Union) and WHO Collaborating Centres, all working together
; to exchange information and virus isolates. The main objectives of the surveillance are (a) to monitor
; the influenza activity (start, intensity, duration) over the whole year, (b) to determine the type and
; subtype/lineage of influenza viruses circulating, (c) to characterise the viruses at the antigenic and
; genetic level, (d) to contribute to the decision process on the yearly influenza vaccine content, (e) to
; assess the overall vaccine effectiveness, (f) to monitor the susceptibility to antivirals of the circulating
; viruses, and (g) to detect the appearance of new (non-seasonal) influenza viruses in the human
; population.

This report includes data from week 24-2024 till the end of week 23-2025.