Euro Surveill. Interim estimates of 2013/14 influenza clinical severity and vaccine effectiveness in the prevention of laboratory-confirmed influenza-related hospitalisation, Canada, February 2014

[Giuseppe]

[Source: Eurosurveillance, full page: (LINK). Abstract, edited.]


Eurosurveillance, Volume 19, Issue 9, 06 March 2014 / Rapid communications

Interim estimates of 2013/14 influenza clinical severity and vaccine effectiveness in the prevention of laboratory-confirmed influenza-related hospitalisation, Canada, February 2014

S A McNeil <SUP>1</SUP>, V Shinde<SUP>2</SUP>, M Andrew<SUP>1</SUP>, T F Hatchette<SUP>1</SUP>, J Leblanc<SUP>1</SUP>, A Ambrose<SUP>1</SUP>, G Boivin<SUP>3</SUP>, W R Bowie<SUP>4</SUP>, F Diaz-Mitoma<SUP>5</SUP>, M ElSherif<SUP>1</SUP>, K Green<SUP>6</SUP>, F Haguinet<SUP>2</SUP>, S Halperin<SUP>1</SUP>, B Ibarguchi<SUP>7</SUP>, K Katz<SUP>8</SUP>, JM Langley<SUP>1</SUP>, P Lagac?-Wiens<SUP>9</SUP>, B Light<SUP>9</SUP>, M Loeb<SUP>10</SUP>, J McElhaney<SUP>5</SUP>, D MacKinnon-Cameron<SUP>1</SUP>, A E McCarthy<SUP>11</SUP>, M Poirier<SUP>12</SUP>, J Powis<SUP>13</SUP>, D Richardson<SUP>14</SUP>, M Semret<SUP>15</SUP>, S Smith<SUP>16</SUP>, D Smyth<SUP>17</SUP>, G Stiver<SUP>4</SUP>, S Trottier<SUP>3</SUP>, L Valiquette<SUP>18</SUP>, D Webster<SUP>19</SUP>, L Ye<SUP>1</SUP>, A McGeer<SUP>6</SUP>, on behalf of the Public Health Agency of Canada/Canadian Institutes of Health Research Influenza Research Network (PCIRN) Serious Outcomes Surveillance Network<SUP>20</SUP>, on behalf of the Toronto Invasive Bacterial Diseases Network (TIBDN)<SUP>21</SUP>
<SUP></SUP>
<SUP>1</SUP>Canadian Center for Vaccinology, IWK Health Centre and Capital Health, Dalhousie University, Halifax, Nova Scotia, Canada - 2 GlaxoSmithKline Biologicals, Wavre, Belgium - 3 CHU de Qu?bec, Quebec, Canada - 4 University of British Columbia, Vancouver, British Columbia, Canada - 5 Advanced Medical Research Institute of Canada, Sudbury, Ontario, Canada - 6 Mount Sinai Hospital, Toronto, Ontario, Canada - 7 GlaxoSmithKline, Mississauga, Ontario, Canada - 8 North York General Hospital, Toronto, Ontario, Canada - 9 St. Boniface Hospital, Winnipeg, Manitoba, Canada - 10 McMaster University, Hamilton, Ontario, Canada - 11 The Ottawa Hospital, Ottawa, Ontario, Canada - 12 Centre de sant? et de service sociaux de Trois-Rivieres, Trois-Rivieres, Quebec, Canada ? 13 Toronto East General Hospital, Toronto, Ontario, C - 14 William Osler Health Centre, Brampton, Ontario, Canada - 15 McGill University, Montreal, Quebec, Canada - 16 University of Alberta, Edmonton, Alberta, Canada - 17 The Moncton Hospital, Moncton, New Brunswick, Canada - 18 Universit? de Sherbrooke, Sherbrooke, Quebec, Canada - 19 Horizon Health, Saint John, New Brunswick, Canada ? 20 www.pcirn.ca - 21 www.tibdn.ca
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Citation style for this article: McNeil SA, Shinde V, Andrew M, Hatchette TF, Leblanc J, Ambrose A, Boivin G, Bowie WR, Diaz-Mitoma F, ElSherif M, Green K, Haguinet F, Halperin S, Ibarguchi B, Katz K, Langley J, Lagac?-Wiens P, Light B, Loeb M, McElhaney J, MacKinnon-Cameron D, McCarthy AE, Poirier M, Powis J, Richardson D, Semret M, Smith S, Smyth D, Stiver G, Trottier S, Valiquette L, Webster D, Ye L, McGeer A, on behalf of the Public Health Agency of Canada/Canadian Institutes of Health Research Influenza Research Network (PCIRN) Serious Outcomes Surveillance Network, on behalf of the Toronto Invasive Bacterial Diseases Network (TIBDN). Interim estimates of 2013/14 influenza clinical severity and vaccine effectiveness in the prevention of laboratory-confirmed influenza-related hospitalisation, Canada, February 2014. Euro Surveill. 2014;19(9):pii=20729. Available online: http://www.eurosurveillance.org/View...rticleId=20729
Date of submission: 24 February 2014
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During the 2013/14 influenza season in Canada, 631 of 654 hospitalisations for laboratory-confirmed influenza enrolled in sentinel hospitals were due to Influenza A. Of the 375 with known subtype, influenza A(H1N1) accounted for 357. Interim unmatched vaccine effectiveness adjusted for age and presence of one or more medical comorbidities was determined by test-negative case?control design to be 58.5% (90% confidence interval (CI): 43.9?69.3%) overall and 57.9% (90% CI: 37.7?71.5) for confirmed influenza A(H1N1).


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[Giuseppe]

Re: Euro Surveill. Interim estimates of 2013/14 influenza clinical severity and vaccine effectiveness in the prevention of laboratory-confirmed influenza-related hospitalisation, Canada, February 2014

From the above text, these conclusions:

(...)

While the demonstrated effectiveness of 58% against serious disease due to influenza is modest, it arguably represents a significant clinical, public health and health service/cost benefit, given the burden of severe disease resulting in hospitalisation and its downstream complications including ICU admission, pneumonia, disability and death. While our data for the current vaccine suggests prevention of almost 60% of influenza hospitalisations with vaccination in a well matched influenza A(H1N1)-dominated season affecting predominantly younger adults with comorbidity, the unchanged vaccine recommended by the World Health Organization for the 2014/15 season may have very different effectiveness (better or worse) in the coming season depending on circulating strains and vaccine match. While an anticipated VE of 58% against hospitalisation is reasonable given the effectiveness observed in 2013/14, ongoing surveillance and mid-season estimates during the coming season will be critical to ensure that the vaccine is performing as anticipated and to provide early signal of possible drift, should the VE be lower than anticipated.

(...)


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