Fig. 4

Tornado diagram showing one-way and multi-way sensitivity and scenario analyses results for a a targeted vaccination strategy and b a universal vaccination strategy

Note1: The x-axis shows the effect of changes in selected variables on the mean incremental cost-effectiveness ratio (ICER) for the base-case taking a societal perspective. The y-axis shows the model parameter that was varied. The bars indicate the mean change in the ICER caused by changes in the value of the indicated variable holding all other parameters similar, whereby a blue bar indicates a lower value of the selected variable(s) as in the baseline and a red bar a higher value of the selected variable(s). Sensitivity analyses with less than 5% changes are not shown. Detailed results are presented in Table S2 in Additional file 2 for targeted vaccination and in Table S3 in Additional file 2 for universal vaccination.

Note2: All scenarios for targeted vaccination were cost-saving and health gaining. This results in negative ICERs.

*Some of the sensitivity analyses were only applicable to universal vaccination (i.e. alternative universal vaccination strategy), and others were only to target vaccination (i.e. lower coverage in the target population).

**No S.A. on vaccine price was performed for targeted vaccination as this was already cost-saving at the current market price; No S.A. on herd immunity, as a population vaccine coverage of 7% will not induce herd protection