Figure 2. Expected Gain in Time to a Pandemic (G) of a Containment Policy as a Function of the Expected Time to Introduction (T) of a Pandemic-Capable Strain .

Either infinite containment attempts (blue) are possible or only a single containment attempt (red) is possible, and we assume an optimistic (80%, solid) or pessimistic (50%, dashed) probability of success for each containment. G is defined as the difference in the expected time to a pandemic under the status quo and the containment policy. The Poisson hazard of introduction of pandemic-capable strains (λ) is the reciprocal of the expected time to introduction (T). The results are identical if the hazard of introduction is fixed but unknown.