Influenza in Europe, summary of the season 2017–18
The influenza 2017/18 surveillance season started in week 40/2017 & ended in week 20/2018. The main surveillance and virological outputs as well as articles on the vaccine vaccine effectiveness for the season is listed below.
All updates from ECDC and key partners on surveillance data and other developments for the influenza 2017-2018 season is also available via a Twitter moment. To reach the list of all updates, please go to Twitter or to the end of the page where we list all the key tweets for the season.
ECDC key updates
Seasonal influenza - Annual Epidemiological Report for 2017 - 2018
22 Oct 2018 - 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%).
Risk assessment for seasonal influenza, EU/EEA, 2017–2018
20 Dec 2017 - First detections indicated circulation of A(H3N2) and B/Yamagata viruses. As the former subtype dominated last season, a high proportion of the population should be protected. However, the emergence of variant strains cannot be excluded and this would increase the likelihood of severe outcomes in the elderly
Influenza Virus Characterisation reports, season 2017/18
The report provides an overview of the technical details of the circulating influenza viruses, such as antigenic and genetic properties, with a reference to the current vaccine strains. It also summaries the developments of the viruses since the last report, as well as the main developments for the ongoing season. Here you find the reports for the 2017/18 season.Read more
Dominant influenza A(H3N2) and B/Yamagata virus circulation in EU/EEA, 2016/17 and 2017/18 seasons, respectively
We use surveillance data to describe influenza A and B virus circulation over two consecutive seasons with excess all-cause mortality in Europe, especially in people aged 60 years and older. Influenza A(H3N2) virus dominated in 2016/17 and B/Yamagata in 2017/18. The latter season was prolonged with positivity rates above 50% among sentinel detections for at least 12 weeks. With a current west–east geographical spread, high influenza activity might still be expected in eastern Europe.Go to the article (Eurosurveillance 29 March 2018)
Interim 2017/18 influenza seasonal vaccine effectiveness: combined results from five European studies
Between September 2017 and February 2018, influenza A(H1N1)pdm09, A(H3N2) and B viruses (mainly B/Yamagata, not included in 2017/18 trivalent vaccines) co-circulated in Europe. Interim results from five European studies indicate that, in all age groups, 2017/18 influenza vaccine effectiveness was 25 to 52% against any influenza, 55 to 68% against influenza A(H1N1)pdm09, −42 to 7% against influenza A(H3N2) and 36 to 54% against influenza B.Go to the article (Eurosurveillance 1 March 2018)
Interim effectiveness of trivalent influenza vaccine in a season dominated by lineage mismatched influenza B, northern Spain, 2017/18
The 2017/18 interim estimate of trivalent influenza vaccine effectiveness (VE) was 39% (95% confidence interval: 20–54) in Navarre. Compared with individuals unvaccinated in the current and five previous seasons, VE against influenza B was 41% for current and any prior doses, 67% for current vaccination only, and 22% for any prior doses, and 43%, 51% and 54%, respectively against influenza A(H3N2). This suggests moderate VE despite predominance of lineage mismatched influenza B.Go to the article (Eurosurveillance 15 Feb 2018)
Early season co-circulation of influenza A(H3N2) and B(Yamagata): interim estimates of 2017/18 vaccine effectiveness, Canada, January 2018
Using a test-negative design, we assessed interim vaccine effectiveness (VE) for the 2017/18 epidemic of co-circulating influenza A(H3N2) and B(Yamagata) viruses. Adjusted VE for influenza A(H3N2), driven by a predominant subgroup of clade 3C.2a viruses with T131K + R142K + R261Q substitutions, was low at 17% (95% confidence interval (CI): −14 to 40). Adjusted VE for influenza B was higher at 55% (95% CI: 38 to 68) despite prominent use of trivalent vaccine containing lineage-mismatched influenza B(Victoria) antigen, suggesting cross-lineage protection.Go to the article (1 Feb 2018)