Starting in July and continuing through August, new cases fueled by the Delta variant spread across the South. Cases then climbed across the Plains, Midwest and Northeast by fall.
And then came Omicron, corresponding with a dramatic rise that overwhelmed the map starting in December before fading again by late January 2022. By early February, the Centers for Disease Control and Prevention estimated 100% of US cases were Omicron.
The animation is based on county-level data collected by local governments and tracked by the Johns Hopkins University Center for Systems Science and Engineering.
You can also view and download a sharable version of this animation.
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Data from Johns Hopkins University Center for Systems Science and Engineering each day starting July 1, 2021. New cases that are missing or not assigned to a particular county are excluded. Due to reporting anomalies, new case counts are omitted for counties in Nebraska from Sept. 25 to Oct. 1, 2021.
Correction: A previous version of the footnote misstated the year in which the animation ends.
