Mr Adams has insisted he would not bring back mask and vaccine mandates, instead focusing on antiviral treatments and at-home testing.

While many American cities long ago jettisoned public health precautions, New York City and other Democrat-run cities like Los Angeles and Philadelphia have taken a more cautious approach to fighting waves of the virus. Now, even as cases and hospitalizations pick up again, these cities could be like the rest of the nation in their focus on returning to normality and personal responsibility.

In New York, rather than sounding the alarm about the city’s increased risk level, Mr Adams has repeatedly stressed that his infection in April was mild, partly because he was taking the antiviral Paxlovid.

“I think the reason we’re here and don’t see any drastic action is because we’ve done an amazing job of telling people – vaccines, boosters,” Mr Adams said at a recent news conference. “When I was hit by Covid it was just a tickle in my throat. I was still able to train, had no breathing problems, no pain.”

Mr Adams, a Democrat who took office in January, appears to be weighing several factors: He has not sought mandates because hospitalizations and deaths have risen at a slower rate than in previous waves, because of the possible political cost of adopting weary public restrictions, and because he is concerned about the impact on the city’s hospitality, tourism and economic comeback.

But some health experts have criticized the mayor’s approach, fearing a wide spread of the virus could hurt the city’s most vulnerable residents. They believe the city should bring back mask and vaccine mandates but concede that doing so would be politically difficult.

The city is now logging more than 4,000 cases a day, a number that is likely much higher since most home tests are not counted in the official count. As of Tuesday, more than 770 people in the city were hospitalized with Covid and 84 were in intensive care units

Mr Adams said this week that he had no plans to bring mandates back unless the hospital system reached a “state of emergency” or trended in that direction. The new alert system, approved by Mr Adams in March, recommends introducing a mask requirement for indoor public spaces at the current risk level.

That’s what health experts argue Waiting until hospitals and health workers are overwhelmed would be too late. Some elected officials, like Manhattan Borough President Mark Levine, support reinstating a mask mandate for most indoor public spaces.

“I want this to be a city that can turn protections on and off if we hit a surge,” Mr. Levine said. “I’d like to see us do more now and push harder.”

In a call Thursday with Anne Williams-Isom, one of Mr Adams’ deputy mayors, community groups and disability advocates expressed their strong support for an indoor mask mandate, according to someone who answered the call. Ms. Williams-Isom said she would convey her message to the mayor.

Mr Adams’ approach echoes the tone of other leaders, such as Gov. Kathy Hochul and President Biden, who are eager to emerge from the pandemic and focus on economic recovery. New Jersey Gov. Philip D. Murphy has also resisted bringing back mandates, rescinding a mask mandate for New Jersey Transit trains going into the city.

Ms Hochul, who recently tested positive for the virus, has maintained a mask mandate for public transit but has failed to impose broader restrictions despite a big spike in New York state. Ms. Hochul faces an additional political calculus – she is in the midst of campaigning for a full term as governor and needs support from more conservative corners of the state.

Many business leaders support the mayor’s approach, including Kathryn Wylde, president of the Partnership for New York City, an influential business group.

“New Yorkers have proven they have the common sense to follow safety protocols, including masks where appropriate,” she said. “Reversing progress towards reopening the city would be a blow to the recovery but also seems unnecessary at this point.”

The city health commissioner, Dr. Ashwin Vasan, issued an executive order Monday urging all residents to wear medical masks in offices, grocery stores, schools and other indoor public spaces across the city. A day later, he announced that the city had reached the high alert level prompted by rising hospital admissions.

Mr Adams said the city would settle into a “new norm” as variants arrive.

“If we have thoughts of shutting down, panic, with every variant that comes up, we’re not going to function as a city,” Mr Adams said on Wednesday.

But former Mayor Bill de Blasio and his health commissioner Dr. Dave Chokshi, who stayed in the Adams administration for the first few months and rolled out the new alert system in March, have made public comments encouraging Mr Adams to be ready to return to mandates.

“I want to say this as a friendly reminder to keep these powerful tools available,” Mr. de Blasio said in a radio interview last week. “You may need them soon.”

Mr de Blasio, who oversaw the city’s response during the worst waves of the virus, held virtual virus briefings almost daily, sometimes inviting outside health experts like Dr. Wafaa El-Sadr, a professor of epidemiology and medicine at the Columbia Mailman School, an of Public Health, and Dr. Celine Gounder, an infectious disease expert at New York University. He introduced some of the country’s most aggressive health measures, including a vaccination mandate for city workers and private employers that is still in place.

Mr. Adams has relied on a handful of key advisors to shape his virus response: Dr. Vasan, an epidemiologist who used to run a mental health nonprofit; dr Mitchell Katz, the city’s hospital system manager; Ms. Williams-Isom, Deputy Mayor for Health and Human Services; Dan Weisberg, first deputy school chancellor; and dr Ted Long, executive director of the city’s Test and Track Corps. The group meets almost every morning for a virtual call to discuss the latest data.

Mr Adams said the message from the hospital and school leaders was clear: “They are all saying the same thing. They say, ‘Listen, we got this. We’re not overwhelmed.’”

But dr Chokshi, the former health commissioner, said in a recent interview that with each new surge of cases in the city, elected officials and New Yorkers often had “collective amnesia” about how to respond.

“People would say, ‘Well, it’s just increasing the cases, let’s see what happens with the hospitalizations,'” he said. “For me, as someone who’s been involved with this and understands epidemiology in particular, it’s hard not to explode when you feel like the public and in many cases the political conversation is going into those circles. And you’re like, ‘Wow, when are we going to learn.’”

Some health experts agreed that unless the health system was seriously overwhelmed, it would be difficult to reintroduce sweeping mandates at this point in the pandemic. At the same time, an alert system whose recommendations are not followed can confuse the public and reduce confidence, especially if the change is not carefully explained.

“It makes perfect sense to pick a set of indicators and use them to decide what steps you’re going to take,” said Dr. Jay Varma, who served as Mr de Blasio’s senior health advisor. “Putting out a weather report is valuable, but you have to be clear about how to use it.”

Lacking mandates, several experts said the Adams administration should do more to convince people of the gravity of the current situation, even among those who are vaccinated and have no personal fear of dying from the virus. For example, an updated public health campaign could focus on the importance of wearing masks to protect the vulnerable, the risks of a long Covid, or the increased risk of cardiovascular disease post-Covid-19.

Mr Adams has focused on getting antiviral drugs like Paxlovid free home delivery and distributing millions of home tests to public school students, libraries and museums. His government says it has distributed 35,000 antiviral treatments that have prevented nearly 2,000 hospitalizations.

The city has led the nation’s vaccination rates, but booster rates have stalled. An estimated 88 percent of adults in the city are fully vaccinated; only 46 percent received a booster shot.

New Yorkers with disabilities and compromised immune systems fear the city’s new approach won’t protect them. Emily Ladau, a disability rights advocate who lives on Long Island and frequents the city, said few people are wearing masks because the mayor hasn’t delivered a clear message that they matter.

“There’s a big difference between masking and lockdown,” she said. “I don’t think it should be that hard to put on a mask and protect the people around you.”

Joseph Goldstein, Sharon Otterman and Dana Rubinstein contributed reporting.