[Source: Eurosurveillance, full page: (LINK). Abstract, edited.]
Eurosurveillance, Volume 21, Issue 16, 21 April 2016 / Surveillance and outbreak report
Pandemic vaccination strategies and influenza severe outcomes during the influenza A(H1N1)pdm09 pandemic and the post-pandemic influenza season: the Nordic experience
JG Cuesta 1 7 , P Aavitsland 2 , H Englund 3 , Ó Gudlaugsson 4 , SH Hauge 5 , O Lyytikäinen 6 , G Sigmundsdóttir 4 , A Tegnell 3 , M Virtanen 6 , the Nordic influenza comparison group 8 , TG Krause 1
Author affiliations: 1. Statens Serum Institut, Copenhagen, Denmark; 2. Epidemi, Kristiansand, Norway; 3. Public Health Agency Sweden, Stockholm, Sweden; 4. Centre for Health Security and Communicable Disease Control, Reykjavik, Iceland; 5. Norwegian Institute of Public Health, Oslo, Norway; 6. National Institute for Health and Welfare, Helsinki, Finland; 7. European Programme for Intervention Epidemiology Training (EPIET), European; Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.; 8. The Nordic influenza comparison group members are listed at the end of the article
Correspondence: Julita Gil Cuesta (firstname.lastname@example.org)
Citation style for this article: Cuesta JG, Aavitsland P, Englund H, Gudlaugsson Ó, Hauge SH, Lyytikäinen O, Sigmundsdóttir G, Tegnell A, Virtanen M, the Nordic influenza comparison group, Krause TG. Pandemic vaccination strategies and influenza severe outcomes during the influenza A(H1N1)pdm09 pandemic and the post-pandemic influenza season: the Nordic experience. Euro Surveill. 2016;21(16):pii=30208. DOI: http://dx.doi.org/10.2807/1560-7917.ES.2016.21.16.30208
Received:14 April 2015; Accepted:03 December 2015
During the 2009/10 influenza A(H1N1)pdm09 pandemic, the five Nordic countries adopted different approaches to pandemic vaccination. We compared pandemic vaccination strategies and severe influenza outcomes, in seasons 2009/10 and 2010/11 in these countries with similar influenza surveillance systems. We calculated the cumulative pandemic vaccination coverage in 2009/10 and cumulative incidence rates of laboratory confirmed A(H1N1)pdm09 infections, intensive care unit (ICU) admissions and deaths in 2009/10 and 2010/11. We estimated incidence risk ratios (IRR) in a Poisson regression model to compare those indicators between Denmark and the other countries. The vaccination coverage was lower in Denmark (6.1%) compared with Finland (48.2%), Iceland (44.1%), Norway (41.3%) and Sweden (60.0%). In 2009/10 Denmark had a similar cumulative incidence of A(H1N1)pdm09 ICU admissions and deaths compared with the other countries. In 2010/11 Denmark had a significantly higher cumulative incidence of A(H1N1)pdm09 ICU admissions (IRR: 2.4; 95% confidence interval (CI): 1.9–3.0) and deaths (IRR: 8.3; 95% CI: 5.1–13.5). Compared with Denmark, the other countries had higher pandemic vaccination coverage and experienced less A(H1N1)pdm09-related severe outcomes in 2010/11. Pandemic vaccination may have had an impact on severe influenza outcomes in the post-pandemic season. Surveillance of severe outcomes may be used to compare the impact of influenza between seasons and support different vaccination strategies.
Keywords: Research; Abstracts; Pandemic Influenza; Vaccines; H1N1pdm09.