Figure 9

Additional scenarios, assuming 40 ring vaccinations or contact tracings possible per day, and that contacts of contacts are traced; all parameters are identical to those in Figure 3A unless otherwise indicated. The figure shows the average of 100 replications of five scenarios (Case a repeats the result from Figure 3A for reference); the numbers in parentheses in the legend are the corresponding fraction of the 100 scenarios for which decontainment occurred. For case b, we assumed that flat and hemorrhagic smallpox cases took four times as long on average to diagnose as ordinary cases; for case c., we assumed that no one in the population had prior protection (as opposed to 25% for Figure 3A); for case d, we assumed that an additional 10% of individuals (13% instead of 3%) would develop mild smallpox (with 75% developing ordinary smallpox instead of 85% as in Figure 3A); and for case e, we assumed that the vaccine is completely ineffective and provides no protection against infection.