Fig. 2
From: Age-specific differences in the dynamics of protective immunity to influenza

Susceptibility after simulated infection with H1N1pdm09 and H3N2 in adults and children. Susceptibility is shown after simulated infection (at time t = 0) for adults with H1N1pdm09 (a) and H3N2 (b) and for children with H1N1pdm09 (c) and H3N2 (d). The black lines represent individual trajectories from one simulation, and the red line represents the median among individuals over 1000 replicate simulations. Curves from individual trajectories are truncated at points corresponding to the end of the study