Hoek, W. van der

influenza vaccination vaccine outbreak disease cluster study surveillance control signal syndromic analysis syndromic surveillance condition pandemic figure netherland cluster-signal effectiveness symptom onset detection 7 days patient health legionnaire number population window estimate cause infection table recurrence interval hospitalisation symptom hospitalization coverage onset result vaccination date influenza vaccination analyses individual index date hospital ≥ 60 years pandemic influenza vaccination database setting 14 days ve estimates 2009 influenza vaccine effectiveness information method statistic time window lri-cluster influenza vaccines ph 1n infection $5 yr adjuvanted laboratory pandemic influenza vaccine activity vaccinated cases level period ph 1n hospitalisation alarm steen pathogen diagnose sensitivity threshold figure 2 breakthrough infections vaccination coverage 7 weeks