Modeling the USA Winter 2021 CoVID-19 Resurgence

The current USA 2021 CoVID-19 Winter Resurgence is modeled here with the same function used for analyzing prior USA CoVID-19 waves: <disp-formula id="ueqn1"> <alternatives> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22268868v1_ueqn1.gif" position="float" orientation="portrait"/> </alternatives> </disp-formula> Here, N ( t ) gives the total number of CoVID-19 cases above the previous baseline, and t _R sets the initial t _dbl = t _R (ln 2) pandemic t _dbl doubling time. Larger α _S values indicate that uninfected people are improving their pandemic mitigation efforts, such as Social Distancing and vaccinations ; while δ ₀ > 0 accelerates the post-peak <inline-formula> <alternatives> <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22268868v1_inline1.gif"/> </alternatives> </inline-formula> tail-off , and is empirically associated with mask-wearing . The pandemic wave end is when N ( t ) no longer increases.

The USA Summer 2021 resurgence results from our prior medrxiv . org preprints ^* were used as a baseline. By 11/15/2021, an additional <inline-formula> <alternatives> <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22268868v1_inline2.gif"/> </alternatives> </inline-formula> cases above baseline were found, signaling the USA Winter 2021 resurgence. This CoVID-19 wave is still in its initial stages. Presently, our analysis indicates that this CoVID-19 wave can infect virtually all susceptible persons; just like the initial stage of the USA Summer 2021 resurgence. Data up through 12/30/2021 gives these paremeter values: <disp-formula id="ueqn2"> <alternatives> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22268868v1_ueqn2.gif" position="float" orientation="portrait"/> </alternatives> </disp-formula> These values are identical to the prior 2020 USA Winter Resurgence results. Also, the <inline-formula> <alternatives> <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22268868v1_inline3.gif"/> </alternatives> </inline-formula> and the <inline-formula> <alternatives> <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22268868v1_inline4.gif"/> </alternatives> </inline-formula> values are similar. However, while the Winter 2020 Resurgence showed a significant mask-wearing effect <inline-formula> <alternatives> <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22268868v1_inline5.gif"/> </alternatives> </inline-formula> , this initial USA Winter 2021 Resurgence shows practically no mask-wearing effects <inline-formula> <alternatives> <inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22268868v1_inline6.gif"/> </alternatives> </inline-formula> . If mask-wearing were to quickly rise to the Winter 2020 levels, it would give these projected totals: <disp-formula id="ueqn3"> <alternatives> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="22268868v1_ueqn3.gif" position="float" orientation="portrait"/> </alternatives> </disp-formula> More robust mask-wearing and enhanced Social Distancing measures could further reduce these values ( with 3 Figures ).