Fig. 1From: Relative incidence and individual-level severity of seasonal influenza A H3N2 compared with 2009 pandemic H1N1Comparison between our study timeline and community epidemics. Timing of study rounds and laboratory detections of pH1N1 and sH3N2 viruses in Hong Kong from 2009 to 2011. The left y-axis applies to the grey bars, the frequency of sample recruitment by week for four study rounds, with the number of each recruitment round of recruitment indicated below the y-axis. Community epidemics were proxied by the product of weekly proportion of ILI cases among all GP consultations and the weekly proportion of positive subtype-specific test results for all influenza A strain (black), pH1N1 (red) and sH3N2 (green)Back to article page