Fig 1.
Left: The contact matrix we use, derived from the contact matrix generated in [3] for the United States. Right: Basic reproduction of an epidemic restricted to top- and bottom-segments of population by age, respectively, where the entire population corresponds to an R0 = 2.7. Note: these figures assume young children pose a transmission risk equal to that of adults. We show corresponding figures where children pose a lower transmission risk in Section 6.
Table 1.
Mortality/ICU rates by age.
Fig 2.
A: No mitigations. B: Containment followed by resumption in transmission levels between 9 and 15 months. (Scale for ICU figure is beds required per 10,000 people in population).
Fig 3.
A: Optimum homogeneous mitigations with natural relative contact patterns. B: Homogeneous measures without the contact matrix. (Scale for ICU figure is beds required per 10,000 people in population).
Fig 4.
A: 2/3 under 39 released at normal levels. B: All under 39 released at normal levels.
Fig 5.
A: 2/3 under 49 released at normal levels. B: All under 49 released at normal levels.
Fig 6.
A: 2/3 under 59 released at normal levels. B: All under 59 released at normal levels.
Fig 7.
Impact on mortalities by age group (in groups of 10 years).
The bottom row of this table shows mortalities in each age group for the optimum homogeneous mitigations scenario, as a fraction of the total population of the age group. Note that this is not the IFR. Each other row corresponds to a scenario discussed in Section 4.2. The values in the cells in these rows show the difference in the mortality rate for each age group for the given scenario, compared with the optimum homogeneous scenario.
Fig 8.
Left: A modified contact matrix for the scenario where children under 10 are 50% less susceptible and 90% less infectious than older age groups. Right: Even after rescaling to correspond to R0 = 2.7, we see that older age groups are still much less capable of sustaining an epidemic on their own than are younger age groups.
Fig 9.
Comparison of the effect of reduced susceptibility and infectiousness of children under 10.
The top two panels are generated using the modified contact matrix described in Fig 8 as a starting point. The bottom two panels are those generated using the contact matrix from Fig 1 as a starting point; note that these bottom panels are identical to the panels shown in Fig 6. We see only small quantitative differences between the top and bottom panels for each of the two strategies shown on the left and right here (releasing 2/3 or all of the under 60 population, respectively).