Effect of specific non-pharmaceutical intervention policies on SARS-CoV-2 transmission in the counties of the United States

Nat Commun. 2021 Jun 11;12(1):3560. doi: 10.1038/s41467-021-23865-8.


Non-pharmaceutical interventions (NPIs) remain the only widely available tool for controlling the ongoing SARS-CoV-2 pandemic. We estimated weekly values of the effective basic reproductive number (Reff) using a mechanistic metapopulation model and associated these with county-level characteristics and NPIs in the United States (US). Interventions that included school and leisure activities closure and nursing home visiting bans were all associated with a median Reff below 1 when combined with either stay at home orders (median Reff 0.97, 95% confidence interval (CI) 0.58-1.39) or face masks (median Reff 0.97, 95% CI 0.58-1.39). While direct causal effects of interventions remain unclear, our results suggest that relaxation of some NPIs will need to be counterbalanced by continuation and/or implementation of others.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Basic Reproduction Number
  • COVID-19 / epidemiology
  • COVID-19 / prevention & control*
  • COVID-19 / transmission*
  • Disease Transmission, Infectious / prevention & control
  • Health Policy*
  • Humans
  • Infection Control / methods*
  • Leisure Activities
  • Masks
  • Natural History
  • Pandemics
  • Quarantine
  • SARS-CoV-2 / isolation & purification
  • Schools
  • United States / epidemiology