Integrated Sentinel Surveillance Linking Genetic, Antigenic, andEpidemiologicMonitoringof Influenza Vaccine-Virus Relatedness and Effectiveness During the 2013–2014 Influenza Season

effectiveness (VE) measures in an integrated platform of influenza monitoring, described here for the 2013–2014 influenza season of resurgent A(H1N1)pdm09 and late-season type B activity. Methods. VE was estimated as [1 − odds ratio] × 100 % and compared vaccination status between individuals who tested positive (cases) and those who tested negative (controls) for influenza virus. Vaccine-virus relatedness was assessed by genomic sequence analysis and hemagglutination inhibition assays