tetano
Editor, Senior Moderator
Clin Infect Dis
. 2020 Dec 23;ciaa1862.
doi: 10.1093/cid/ciaa1862. Online ahead of print.
Influenza vaccine effectiveness against all-cause mortality following laboratory-confirmed influenza in older adults, 2010-2011 to 2015-2016 seasons in Ontario, Canada
Hannah Chung[SUP] 1 [/SUP], Sarah A Buchan[SUP] 1 2 3 [/SUP], Aaron Campigotto[SUP] 4 5 [/SUP], Michael A Campitelli[SUP] 1 [/SUP], Natasha S Crowcroft[SUP] 1 3 6 7 [/SUP], Vinita Dubey[SUP] 3 8 [/SUP], Jonathan B Gubbay[SUP] 2 4 7 [/SUP], Timothy Karnauchow[SUP] 9 10 [/SUP], Kevin Katz[SUP] 11 [/SUP], Allison J McGeer[SUP] 3 7 12 [/SUP], J Dayre McNally[SUP] 9 [/SUP], Samira Mubareka[SUP] 13 [/SUP], Michelle Murti[SUP] 2 3 [/SUP], David C Richardson[SUP] 14 [/SUP], Laura C Rosella[SUP] 1 2 3 [/SUP], Kevin L Schwartz[SUP] 1 2 3 [/SUP], Marek Smieja[SUP] 15 [/SUP], George Zahariadis[SUP] 5 16 [/SUP], Jeffrey C Kwong[SUP] 1 2 3 6 17 18 [/SUP]
Affiliations
Abstract
Background: Older adults are at increased risk of mortality from influenza infections. We estimated influenza vaccine effectiveness (VE) against mortality following laboratory-confirmed influenza.
Methods: Using a test-negative design study and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against all-cause mortality following laboratory-confirmed influenza for community-dwelling adults aged >65 years during the 2010-2011 to 2015-2016 influenza seasons.
Results: Among 54,116 older adults tested for influenza across the 6 seasons, 6,837 died within 30 days of specimen collection. Thirteen percent (925 individuals) tested positive for influenza, and 50.6% were considered vaccinated for that season. Only 23.2% of influenza test-positive cases had influenza recorded as their underlying cause of death. Before and after multivariable adjustment, we estimated VE against all-cause mortality following laboratory-confirmed influenza to be 20% (95%CI, 8%-30%) and 20% (95%CI, 7%-30%), respectively. This estimate increased to 34% after correcting for influenza vaccination exposure misclassification. We observed significant VE against deaths following influenza confirmation during 2014-2015 (VE=26% [95%CI, 5%-42%]). We also observed significant VE against deaths following confirmation of influenza A/H1N1 and A/H3N2, and against deaths with COPD as the underlying cause.
Conclusions: These results support the importance of influenza vaccination in older adults, who account for most influenza-associated deaths annually.
Keywords: Influenza vaccine; mortality; older adults; vaccine effectiveness.
. 2020 Dec 23;ciaa1862.
doi: 10.1093/cid/ciaa1862. Online ahead of print.
Influenza vaccine effectiveness against all-cause mortality following laboratory-confirmed influenza in older adults, 2010-2011 to 2015-2016 seasons in Ontario, Canada
Hannah Chung[SUP] 1 [/SUP], Sarah A Buchan[SUP] 1 2 3 [/SUP], Aaron Campigotto[SUP] 4 5 [/SUP], Michael A Campitelli[SUP] 1 [/SUP], Natasha S Crowcroft[SUP] 1 3 6 7 [/SUP], Vinita Dubey[SUP] 3 8 [/SUP], Jonathan B Gubbay[SUP] 2 4 7 [/SUP], Timothy Karnauchow[SUP] 9 10 [/SUP], Kevin Katz[SUP] 11 [/SUP], Allison J McGeer[SUP] 3 7 12 [/SUP], J Dayre McNally[SUP] 9 [/SUP], Samira Mubareka[SUP] 13 [/SUP], Michelle Murti[SUP] 2 3 [/SUP], David C Richardson[SUP] 14 [/SUP], Laura C Rosella[SUP] 1 2 3 [/SUP], Kevin L Schwartz[SUP] 1 2 3 [/SUP], Marek Smieja[SUP] 15 [/SUP], George Zahariadis[SUP] 5 16 [/SUP], Jeffrey C Kwong[SUP] 1 2 3 6 17 18 [/SUP]
Affiliations
- PMID: 33354709
- DOI: 10.1093/cid/ciaa1862
Abstract
Background: Older adults are at increased risk of mortality from influenza infections. We estimated influenza vaccine effectiveness (VE) against mortality following laboratory-confirmed influenza.
Methods: Using a test-negative design study and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against all-cause mortality following laboratory-confirmed influenza for community-dwelling adults aged >65 years during the 2010-2011 to 2015-2016 influenza seasons.
Results: Among 54,116 older adults tested for influenza across the 6 seasons, 6,837 died within 30 days of specimen collection. Thirteen percent (925 individuals) tested positive for influenza, and 50.6% were considered vaccinated for that season. Only 23.2% of influenza test-positive cases had influenza recorded as their underlying cause of death. Before and after multivariable adjustment, we estimated VE against all-cause mortality following laboratory-confirmed influenza to be 20% (95%CI, 8%-30%) and 20% (95%CI, 7%-30%), respectively. This estimate increased to 34% after correcting for influenza vaccination exposure misclassification. We observed significant VE against deaths following influenza confirmation during 2014-2015 (VE=26% [95%CI, 5%-42%]). We also observed significant VE against deaths following confirmation of influenza A/H1N1 and A/H3N2, and against deaths with COPD as the underlying cause.
Conclusions: These results support the importance of influenza vaccination in older adults, who account for most influenza-associated deaths annually.
Keywords: Influenza vaccine; mortality; older adults; vaccine effectiveness.