This study reports on the epidemiology of hospitalisation with confirmed influenza, estimate vaccine coverage and influenza vaccine protection against hospitalisation with influenza during the 2012 influenza season. In this observational study, cases were defined as patients admitted to one of the sentinel hospitals with influenza confirmed by nucleic acid detection. Controls were patients who had acute respiratory illnesses who were test-negative for influenza. Vaccine effectiveness was estimated as 1 minus the odds ratio of vaccination in case patients compared with control patients, after adjusting for known confounders. During the period 9 April to 31 October 2012, 1,231 patients were admitted with confirmed influenza at the 15 FluCAN sentinel hospitals. Of these, 47% were more than 6...