tetano
Editor, Senior Moderator
Eurosurveillance, Volume 21, Issue 43, 27 October 2016
Research article
Real-time real-world analysis of seasonal influenza vaccine effectiveness: method development and assessment of a population-based cohort in Stockholm County, Sweden, seasons 2011/12 to 2014/15
A Leval [SUP]1[/SUP] [SUP]2[/SUP] [SUP]3[/SUP] [SUP]4[/SUP] , MP Hergens [SUP]1[/SUP] [SUP]2[/SUP] [SUP]4[/SUP] , K Persson [SUP]1[/SUP] , ? ?rtqvist [SUP]1[/SUP] [SUP]2[/SUP]
+ Author affiliations
1. Department of Communicable Disease Control and Prevention for Stockholm County, Stockholm, Sweden
2. Infectious Disease Unit, Karolinska Institutet, Department of Medicine Solna, Solna, Sweden
3. Janssen-Cilag, Solna, Sweden
4. These authors contributed equally to this manuscript
Correspondence: ?ke ?rtqvist (ake.ortqvist@sll.se)
Citation style for this article: Leval A, Hergens MP, Persson K, ?rtqvist ?. Real-time real-world analysis of seasonal influenza vaccine effectiveness: method development and assessment of a population-based cohort in Stockholm County, Sweden, seasons 2011/12 to 2014/15. Euro Surveill. 2016;21(43)
ii=30381. DOI: http://dx.doi.org/10.2807/1560-7917.ES.2016.21.43.30381
Received:20 May 2016; Accepted:12 September 2016
[h=4][/h]
Real-world estimates of seasonal influenza vaccine effectiveness (VE) are important for early detection of vaccine failure. We developed a method for evaluating real-time in-season vaccine effectiveness (IVE) and overall seasonal VE. In a retrospective, register-based, cohort study including all two million individuals in Stockholm County, Sweden, during the influenza seasons from 2011/12 to 2014/15, vaccination status was obtained from Stockholm?s vaccine register. Main outcomes were hospitalisation or primary care visits for influenza (International Classification of Disease (ICD)-10 codes J09-J11). VE was assessed using Cox multivariate stratified and non-stratified analyses adjusting for age, sex, socioeconomic status, comorbidities and previous influenza vaccinations. Stratified analyses showed moderate VE in prevention of influenza hospitalisations among chronically ill adults ≥ 65 years in two of four seasons, and lower but still significant VE in one season; 53% (95% confidence interval (CI): 33?67) in 2012/13, 55% (95% CI: 25?73) in 2013/14 and 18% (95% CI: 3?31) in 2014/15. In conclusion, seasonal influenza vaccination was associated with substantial reductions in influenza-specific hospitalisation, particularly in adults ≥ 65 years with underlying chronic conditions. With the use of population-based patient register data on influenza-specific outcomes it will be possible to obtain real-time estimates of seasonal influenza VE.
full article
http://eurosurveillance.org/ViewArticle.aspx?ArticleId=22625
Research article
Real-time real-world analysis of seasonal influenza vaccine effectiveness: method development and assessment of a population-based cohort in Stockholm County, Sweden, seasons 2011/12 to 2014/15
A Leval [SUP]1[/SUP] [SUP]2[/SUP] [SUP]3[/SUP] [SUP]4[/SUP] , MP Hergens [SUP]1[/SUP] [SUP]2[/SUP] [SUP]4[/SUP] , K Persson [SUP]1[/SUP] , ? ?rtqvist [SUP]1[/SUP] [SUP]2[/SUP]
+ Author affiliations
1. Department of Communicable Disease Control and Prevention for Stockholm County, Stockholm, Sweden
2. Infectious Disease Unit, Karolinska Institutet, Department of Medicine Solna, Solna, Sweden
3. Janssen-Cilag, Solna, Sweden
4. These authors contributed equally to this manuscript
Correspondence: ?ke ?rtqvist (ake.ortqvist@sll.se)
Citation style for this article: Leval A, Hergens MP, Persson K, ?rtqvist ?. Real-time real-world analysis of seasonal influenza vaccine effectiveness: method development and assessment of a population-based cohort in Stockholm County, Sweden, seasons 2011/12 to 2014/15. Euro Surveill. 2016;21(43)
ii=30381. DOI: http://dx.doi.org/10.2807/1560-7917.ES.2016.21.43.30381Received:20 May 2016; Accepted:12 September 2016
[h=4][/h]
Real-world estimates of seasonal influenza vaccine effectiveness (VE) are important for early detection of vaccine failure. We developed a method for evaluating real-time in-season vaccine effectiveness (IVE) and overall seasonal VE. In a retrospective, register-based, cohort study including all two million individuals in Stockholm County, Sweden, during the influenza seasons from 2011/12 to 2014/15, vaccination status was obtained from Stockholm?s vaccine register. Main outcomes were hospitalisation or primary care visits for influenza (International Classification of Disease (ICD)-10 codes J09-J11). VE was assessed using Cox multivariate stratified and non-stratified analyses adjusting for age, sex, socioeconomic status, comorbidities and previous influenza vaccinations. Stratified analyses showed moderate VE in prevention of influenza hospitalisations among chronically ill adults ≥ 65 years in two of four seasons, and lower but still significant VE in one season; 53% (95% confidence interval (CI): 33?67) in 2012/13, 55% (95% CI: 25?73) in 2013/14 and 18% (95% CI: 3?31) in 2014/15. In conclusion, seasonal influenza vaccination was associated with substantial reductions in influenza-specific hospitalisation, particularly in adults ≥ 65 years with underlying chronic conditions. With the use of population-based patient register data on influenza-specific outcomes it will be possible to obtain real-time estimates of seasonal influenza VE.
full article
http://eurosurveillance.org/ViewArticle.aspx?ArticleId=22625