Modeling layered non-pharmaceutical interventions against SARS-CoV-2 in the United States with Corvid

Dennis L Chao; Assaf P Oron; Devabhaktuni Srikrishna; Michael Famulare

The number of people infected depends on the age of the index case. For example, if an index case is a school-aged child (indicated by "1" on the plot), the number of secondary cases is higher than for other age groups. Also, the secondary cases are not representative of the general population -school-aged children are also over-represented among infectees. R 0 should be defined as the number of secondary cases generated by a "typical" case. Therefore, we tally the number of secondary cases generated by all index cases across runs to get a better idea of who is more likely to be a "typical" infecter. We weight the relationship based on the proportion of secondary cases in each age bin; we put more weight on the high transmission from school children than the lower transmission from adults in our R 0 calculation ( Figure 9 ). For the default model, we set R 0 to be 2.6 (β=0.168206), but we also test R 0 =2.0. These estimates are in line with the literature [26] [27] [28] . We often initialize the model with more than one infected individual. When you seed with one, there is a high probability that an epidemic does not take off.