First, there was Los Angeles County, where the rising menace posed by the delta variant of the coronavirus prompted health officials to reimpose a mask mandate. Then, Bay Area health officers on Friday recommended that residents of seven counties and the city of Berkeley, Calif., resume wearing masks indoors. Mask mandates are being discussed, too, in coronavirus hot spots such as Arkansas and Missouri, where cases have sharply increased in recent weeks and many residents remain unvaccinated.
