France and Spain are on the leading edge of a resurgence in Covid-19 cases across Europe in the wake of the summer travel season, in some cases reaching levels of incidence on par with those in the U.S.

In response, authorities are enacting tailored, localized measures to combat outbreaks, while exhorting citizens to protect themselves and others by behaving prudently…

“At most—if things go badly—we might need to intervene with targeted, restrictive measures in very limited parts of the country,” said Italian Prime Minister Giuseppe Conte. His country had one of the most stringent lockdowns this spring, which included shutting down much of industry…

Mr. Goosens said he is now advising policy makers to shift their messaging and ask people not to rely on government measures but to take personal responsibility to curb the disease by adhering to social distancing, wearing masks, avoiding crowded spaces, and staying away from people at greater risk.