key: cord-0719755-8bob0yi9
authors: Zhang, Y.; Keegan, L. T.; Yuqing, Q.; Samore, M. H.
title: The real time effective reproductive number for COVID-19 in the United States
date: 2020-05-13
journal: nan
DOI: 10.1101/2020.05.08.20095703
sha: 738f6e63ad54c105b949ef915dee82359f6b666d
doc_id: 719755
cord_uid: 8bob0yi9

none.

The overall downward trend indicates that most states have been able to reduce the reproductive number of SARS-CoV-2. However, few states have demonstrated an ability to maintain R t below one in a statistically significant manner. An uptick of R t around the beginning of May might indicate that political protests or exhaustion for social distancing may be impacting our ability to control COVID-19. While we find that both methods show a drop in R t , we find a significant difference in the timing of R t <1. As noted in Lipsitch et al. 2020 5 , the difference is consequential enough to impact policy decision making, highlighting the importance of method selection for R t estimation. We find that the median difference in timing of R t <1 between the two methods is approximately one week.

Although data quality issues plagued early estimates of R t , we believe our estimates of R t are beneficial for tracking the impacts of lifting restrictions on social activity and reducing NPIs. Given the utility of R t , we plan to continue hosting and managing the web interface throughout the COVID-19 pandemic. We believe this product is crucial to help policy makers track the progress of current policies and modulate future risk levels. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted May 13, 2020 . . https://doi.org/10.1101 /2020 

A new framework and software to estimate time-varying reproduction numbers during epidemics

Association of Public Health Interventions With the Epidemiology of the COVID-19 Outbreak in Wuhan, China