Extended Data Fig. 10: Weekly change of Rt in response to the change of weekly cases per 100,000 people at county level.
From: Burden and characteristics of COVID-19 in the United States during 2020

The analysis was performed for five US regions (Northeast, Southeast, Midwest, Southwest, West) during the spring (Feb 21 – May 31), summer (Jun 1 – Sep 15), and fall/winter (Sep 16 – Dec 31) waves. In the five US regions, 116, 162, 126, 45 and 54 counties that reported cumulative cases over 100 per 100,000 people during all three waves and had a population over 100,000 were included in the analysis. A positive/negative change of weekly cases in the x-axis indicates increasing/decreasing community prevalence of COVID-19. The dash lines are the linear fits. The statistical significance of the slope is indicated by asterisks (two-sided t-test. ***: p < 10−5, **: p < 0.001, *: p < 0.05; NS: not significant. P-values are reported in the legends).