But in New York, New Jersey and California, mask mandates remained in force for everyone at least for now.
And in Kansas City, Mo., Mayor Quinton Lucas in a matter of about seven hours said he would not change his mask order, then that he would think about it, then that he was getting rid of it altogether because there was no good way to know who was fully vaccinated and who was not.
“While I understand the C.D.C.’s theory that they could just create a rule that says vaccinated folks go anywhere without a mask, and everybody else who’s unvaccinated will follow it, I don’t know if that’s the type of rule that was written in coordination with anyone who has been a governor or a mayor over the last 14 months,” said Mr. Lucas, a Democrat.
The abrupt decision by the Centers for Disease Control and Prevention to free fully vaccinated people from its mask guidance in most indoor and outdoor settings set off a scramble on Friday across the country to update local rules and redefine social norms.
Major corporations and local shopkeepers weighed whether to take down “masks-required” signs on their doors. People heading to the office or coffee shop or grocery store had to navigate rapidly shifting scientific advice and government restrictions. And surprised state and local officials, including some who withstood months of protests and lawsuits to keep mask orders in place, said they needed time to evaluate the new federal guidance.
In Texas, which lifted mask rules in early March, Chuck Massey, 82, in San Antonio said on Friday that he was comforted by the sight of people wearing masks even after both state and federal officials continue to ease restrictions. Mr. Massey, who suffers from high blood pressure, said he’s taking a “wait and see” approach before he gets the vaccine. But he said he plans to wear a mask no matter what the government says. “The mask is the safest approach, no matter what everyone says,” he said.
In Massachusetts, Joseph Skenderian, one of the owners of Skenderian Apothecary, a pharmacy in Cambridge, smiled on Friday when asked about the agency’s new guidance — visibly, because he was unmasked as he worked with his employees behind a glass partition that separated the group, all fully vaccinated, from any customers. He said he and the workers would continue wearing masks with customers until officials said that people no longer needed to be masked in medical facilities.
He said he trusted that the C.D.C. was being guided by science and data, and so he took the new policy as a sign of how far things have come. “I am personally ecstatic about it because I didn’t think this would happen for another year,” h
e said, “so I think we’ve had tremendous success with the vaccine and everything we’ve done.”
For more than a year, masking had been urged by public health experts, a key to stopping the airborne spread of the coronavirus. Some places allowed their mask requirements to expire months ago, but face coverings remained mandatory in some form in more than 20 states, as well as many cities and counties. Just a few weeks ago, the C.D.C. said fully vaccinated Americans could usually forego masks outdoors, but should continue wearing them in public spaces indoors.
The agency changed course on Thursday, saying people who were at least two weeks past their final dose of a vaccine could safely go most places, both indoors and outdoors, without a mask. The C.D.C. said everyone should still wear a mask in certain settings, including health care facilities, on public transportation and on flights.
The reversal left officials at all levels of government scrambling, with a fast-moving series of announcements and news conferences that continued through midday Friday. Many public health experts and local officials said they were puzzled about how to implement the new advice since there was no national system for differentiating the people who are fully vaccinated — now 36 percent of Americans — from the 64 percent who are not.
In Congress, the Capitol’s attending physician said fully vaccinated members could “resume activities that you did prior to the pandemic,” but that a mask mandate on the House floor would remain in place. And in Nevada, the state’s Gaming Control Board said it would leave mask rules up to individual businesses, and that it was “not practical for the Board to attempt to enforce a mask mandate tethered to an individual’s vaccination status.”
Edgar Sandoval and Kate Taylor contributed reporting.
LONDON — Prime Minister Boris Johnson of Britain said on Friday that vaccination protocols would be changed to swiftly deliver second doses to people over 50-years-old to combat the spread of a coronavirus variant first detected in India, a warning sign for countries that are easing restrictions even though their own vaccination campaigns are incomplete.
“We believe this variant is more transmissible than the previous ones,” Mr. Johnson said. What remained unclear, he said, was by how much. The infectiousness of the variant first detected in India remains the subject of intense study and some leading experts have said it is too early to assess its transmissibility.
If it proves significantly more transmissible, he said, “we face some hard choices.” He added that there was no evidence that the variant was more likely to cause serious illness and death, and there was no evidence to suggest vaccines were less effective against the variant in preventing serious illness and death.
While he said the country would not delay plans to ease restrictions on Monday, he warned that the spread of the variant could force the government to change course.
“This new variant could pose a serious disruption to our progress,” he said at a news conference on Friday.
The numbers of cases involving the variant, known as B.1.617, rose from 520 last week to 1,313 cases this week in Britain, according to official statistics.
The extent to which the variant has spread globally is unclear, because most countries lack the genomic surveillance capabilities employed in England.
That surveillance capability has allowed health officials in Britain to spot the rise of concerning variants more quickly than other nations, offering an early warning system of sorts as a variant seen in one nation almost invariably pops up in others.
Most cases detected in Britain are in northwestern England. The focus has been on Bolton, a town of nearly 200,000 that has one of the country’s highest rates of infection and where health officials have warned of widespread community transmission of the variant. Some cases have also been reported in London. The rapid spread of the variant has led officials to debate speeding…