The Futures of the Pandemic in the USA : A Timed Intervention Model

We propose a novel Timed Intervention exended SEIR model for predicting the evolution of the Covid 19 Pandemic in the USA. The model can, by sparameter, assignment, be reduced to the model of Peng et al, which appeared in February, 2020 (Reference [2]). Novel aspects of the proposed model include

• Formulation of a “Protected” population P , which can be viewed as a “Sheltered in Place”, unexposed population which, starting at time t = τ _P , builds up and stores a reservoir of unexposed Population;

• This “Protection Intervention” provides the basis for a second Timed Release Intervention: on receiving a “reopening signal” at time t = τ _R , this second intervention initiates a release of this stored population back into the general population S .;

• Selection of model parameters to optimize the approximation of the model up to the present, and then projecting simulation of the model based on the value thus obtained 100,200, 365, and 730 days into the future.

This model shows excellent qualitative results and quantitative results that are good, considering the chosen nationwide scope. These results compare favorably to University of Washington IHME [5] projections, as published Daily on the <ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://Worldometers.info">http://Worldometers.info</ext-link> website. The qualitative and quantitative behavior of all 7 state variables S, P, E, I, Q, R, D will be illustrated and discussed, in this and future further Intervention cycles ¹