Age groups that sustain resurging COVID-19 epidemics in the United States

Science. 2021 Mar 26;371(6536):eabe8372. doi: 10.1126/science.abe8372. Epub 2021 Feb 2.


After initial declines, in mid-2020 a resurgence in transmission of novel coronavirus disease (COVID-19) occurred in the United States and Europe. As efforts to control COVID-19 disease are reintensified, understanding the age demographics driving transmission and how these affect the loosening of interventions is crucial. We analyze aggregated, age-specific mobility trends from more than 10 million individuals in the United States and link these mechanistically to age-specific COVID-19 mortality data. We estimate that as of October 2020, individuals aged 20 to 49 are the only age groups sustaining resurgent SARS-CoV-2 transmission with reproduction numbers well above one and that at least 65 of 100 COVID-19 infections originate from individuals aged 20 to 49 in the United States. Targeting interventions-including transmission-blocking vaccines-to adults aged 20 to 49 is an important consideration in halting resurgent epidemics and preventing COVID-19-attributable deaths.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Basic Reproduction Number
  • COVID-19 / epidemiology*
  • COVID-19 / mortality
  • COVID-19 / prevention & control
  • COVID-19 / transmission*
  • COVID-19 Vaccines
  • Cell Phone
  • Child
  • Child, Preschool
  • Communicable Disease Control
  • Epidemics* / prevention & control
  • Humans
  • Infant
  • Middle Aged
  • Models, Theoretical
  • Pandemics / prevention & control
  • Schools
  • United States / epidemiology
  • Young Adult


  • COVID-19 Vaccines