DENVER—The first case in the United States of a seemingly more contagious variant of the coronavirus that has raised alarm in Britain—in a Colorado man who hadn’t been traveling—has triggered a host of questions about how it got here and adding urgency to the nation’s vaccination drive.
The patient, who is in his 20s, is recovering in isolation in Elbert County, a mostly rural expanse on the edge of the Denver metropolitan area, officials said Dec. 29. His condition wasn’t disclosed.
