During the 2017–2018 season, 41 315 specimens from sentinel primary care providers were tested for influenza, 22% more than in the previous season; 49% of the specimens were positive for influenza virus (previous season: 40%).
Although the overall number of influenza detections in the majority of EU/EEA countries is still low, indications show that influenza circulation is above the seasonal threshold in Croatia, which is unusually early. The main reported subtype among the cases recorded in EU/EEA during the past month is A(H3N2), which disproportionally affects older people, and is associated with lower vaccine effectiveness. This is a sign that the upcoming influenza season could be severe for elderly people, and that influenza patterns may vary between countries in terms of timing.
The World Health Organization (WHO) has recommended the composition of the trivalent influenza vaccine for the southern hemisphere winter 2018 influenza season in a report published 28 September 2017.
The virological influenza pattern observed was not consistent enough to make a clear prediction for the 2011-2012 season in Europe. In general, the findings on the impact of influenza in the southern hemisphere in 2011 were reassuring for Europe, and the match of the A(H3N2) viruses with the vaccine was considered good.