Fig. S3.

Association between pre-season HI titer and infection and illness status for each subtype in season 1 and 2. Each plot shows HI titers, which fall into up to nine discrete values but have been dispersed for visualization. Geometric mean titers are shown within the plots for each group and for the combined infected groups. Odds ratios with confidence intervals and p values for the association between pre-season titer and influenza-like-illness (ILI) development amongst infected participants are shown above each plot.