Power Analysis for the Repeated Low-Dose Challenge Design and the Single Low-Dose Challenge Design

<p>In our virtual experiments, we set the challenge dose equal to the <i>ID</i>₅₀, and assumed that the vaccine efficacy was 67% (dotted lines), 80% (dashed lines), or 90% (solid lines). The graph shows the statistical power of the repeated low-dose challenge design (black lines) and the single low-dose challenge design (green lines) for a given number of animals per group as determined from 100,000 virtual experiments. If the vaccine is 90% effective, the statistical power of the repeated low-dose challenge design is higher than 95% with only five animals per group, as compared to only 15% for the single low-dose challenge design.