Sensitivity analyses for the variation in the optimal switch-time (days) with different treatment levels and R0 = 1.3 for (a) unlimited, and (b) limited (1.8%) stockpile of zanamivir. Sensitivity analyses for the variation in the ratio of cumulative number of oseltamivir-resistance (TOr/Tinf) with different treatment levels and R0 = 1.3 for (a) unlimited, and (b) limited (1.8%) stockpile of zanamivir. The ranges of other parameter values used for these simulations are given in Table 1 of the main text. For a given treatment level, the circle with a dot at the center is the median of the optimal switch-time, the wide bars show the extent of the inter-quartile range, the lines represent the extent of data points that is not outlying, and the empty circles indicate outliers.