Spatially refined time-varying reproduction numbers of SARS-CoV-2 in Arkansas and Kentucky and their relationship to population size and public health policy, March - November 2020.

Purpose: To examine the time-varying reproduction number, R, for COVID-19 in Arkansas and Kentucky and investigate the impact of policies and preventative measures on the variability in R.

Methods: Arkansas and Kentucky county-level COVID-19 cumulative case count data (March 6-November 7, 2020) were obtained. R was estimated using the R package 'EpiEstim', by county, region (Delta, non-Delta, Appalachian, non-Appalachian), and policy measures.