Figure 6. Optimal cost-effectiveness of antiviral (AV) and test stockpiling (0–30 million units) for a clinical attack rate (CAR) of 25% under the A) 1918 and B) 1957/69 scenarios. The composite test (Test A) and a perfect test of 100% sensitivity and 100% specificity (Test B) are included. The most cost-effective strategies lie on the efficiency line. ILI, influenza-like illness; QALY, quality-adjusted life year.