Association between the 2008–09 Seasonal Influenza Vaccine and Pandemic H1N1 Illness during Spring–Summer 2009: Four Observational Studies from Canada
Fully adjusted effect measures and 95% confidence intervals from four epidemiologic studies in Canada to assess the association between 2008–09 trivalent inactivated influenza vaccine (TIV) and risk of community-based seasonal influenza and pH1N1 illness. *Note: Boxes show point estimates for the OR for each study/subgroup except the Quebec prospective cohort study for which the effect measure displayed is the RR. See Tables 1, 3, and 5 for covariates included in adjusted analyses. RR for the Quebec prospective cohort study was age-stratified but not further adjusted (see tables 1 and 6). LCL, lower confidence limit; UCL, upper confidence limit.