A kindergartner in Queens wasn’t quite ready to part with his Mickey Mouse masks. On Staten Island, another kindergartner had lost one of his bottom teeth and couldn’t wait to show off his new smile.And one high school student, Ella Chan, 17, a junior at Stuyvesant High School in Manhattan, said she was keeping her mask on. “There really is no cure for Covid at this point,” she said. “There’s just too much uncertainty for me.”Two years after the coronavirus pandemic gripped New York, Monday marked the city’s most aggressive move yet to return to normalcy. Officials on Monday eliminated a school mask mandate that had been in place since the fall of 2020, a major milestone in the city’s recovery from a public health crisis that upended the lives of nearly 1 million students in the nation’s largest school district.It came on the same day that the city also suspended its proof of vaccination requirement to enter restaurants, gyms and other entertainment venues.The moves underscore Mayor Eric Adams’s intensive push to revive the city and bring its schools, businesses and street life back to normal, a campaign he considers essential for resuscitating the city’s pandemic-stricken economy.“We did our jobs as New Yorkers, and now we’re winning,” Mr. Adams said on Monday in a television interview.Though many business leaders, the teachers’ union and the city’s health officials have applauded the effort, some health experts and other elected officials have raised concerns that it might be too soon to lift many restrictions, including around masks.And around the city, students, parents and school employees all wondered whether it was time for New York to return to life before the pandemic or if another crushing setback lurked around the corner.On Staten Island, Emma Billera, 7, a second-grader at Public School 001 Tottenville, said taking her mask off made her feel “happy, so you can breathe.”But at Nelson Mandela High School in the Crown Heights neighborhood in Brooklyn, LaShawn Farrell expected her daughter, a ninth grader who has not been vaccinated, to keep her mask on.“I don’t think taking off the mask right now is something that’s being safe,’’ Ms. Farrell said, adding that she did not think vaccines were safe for her child.Other major cities have also loosened school mask mandates in recent weeks. Dallas and Houston have made masks optional at schools. Los Angeles County will end its school mask requirements after March 11, allowing school districts to set their own rules. But the City of Los Angeles will keep masks in place in its schools, the nation’s second largest district.Chicago school officials announced plans on Monday to lift the mask mandate for the nation’s third-largest school district as of March 14, angering its teachers’ union. New Jersey’s school mask mandate was also lifted on Monday.And the Supreme Court on Monday rejected the latest effort by New York City teachers to challenge the vaccine mandate.In New York City, children under 5 are still required to wear masks in day care and preschool settings, which has angered some parents. A protest against the rule was held on Monday in City Hall Park.“My daughter was two years old when this started,” said Daniela Jampel, 38, who has three children _ a 7-month-old, a 4-year-old, and an 8-year-old. “She doesn’t even remember a time before Covid — it is inconceivable to her.”Updated March 7, 2022, 3:33 p.m. ET“She deserves normalcy, and she deserves normalcy because everyone else is getting it,” Ms. Jampel said.The easing of pandemic rules marks a significant step in New York City, which was an early epicenter of the pandemic and where more than 39,900 have died, according to a New York Times database.Mr. Adams on Monday said that the city had taken a “very conservative approach” on removing restrictions, but that cases were low enough now to do so.“Covid is no longer in control of our lives,’’ Mr. Adams said. “We are in control of our lives.”While the proof of vaccination requirement has been eliminated for many indoor settings, they remain in place at some venues, including Broadway theaters, as well as on public transit.Mr. Adams said that he would also eventually remove the mask mandate for younger children once he can be assured that cases do not start rising for older students.He asked parents to trust him. “We are going to get there,” the mayor said.The city’s health commissioner, Dave Chokshi, said the decision on school masks was driven by data. “We’re at a lower level of transmission than we’ve been in the past and almost equally importantly, the levels of vaccination are significantly higher than they have been previously,’’ he said.An average of 555 people in New York City have tested positive each day over the last week, down from an average of 43,000 per day in early January at the height of the Omicron surge. Deaths have dropped from nearly 130 a day in early January to eight per day.Michael Mulgrew, the president of the United Federation of Teachers, said he hoped that Monday would be remembered as a “milestone day” for the city’s schools.“It’s been a long time that we waited to be in this position,’’ said Mr. Mulgrew, adding that it would be important to continue monitoring case numbers and adjusting safety precautions if warranted.In New Jersey, the governor gave districts the option to set their own rules. Administrators in many of the state’s large cities — including Newark, Paterson and Trenton — were still requiring students and staff members to wear masks; other districts have adopted metric-based policies that will change as the virus infection rate fluctuates.At Cranford High School in northern New Jersey, where masks were no longer required, a majority of the teenagers who raced inside before the bell rang were unmasked. Some students wore them hooked below their chin. Others approached the entrance tentatively, and seemed uneasy to be shedding a mask that, for some students, had become as much social crutch as safety precaution.Vaccines have played a central role in New York City’s effort to contain the virus and officials have waged a relentless campaign to get people vaccinated. Seventy-eight percent of all residents are fully vaccinated.Public schools with low vaccination rates tend to be in neighborhoods with low vaccination rates, but that is not always the case, and the differences between the adult and child vaccination rates can be extreme.In Ocean Hill-Brownsville, Brooklyn, a mostly Black and Hispanic neighborhood, 86 percent of adults are fully vaccinated. But only 26 percent of children at one local school, P.S. 41, are fully vaccinated, and that rate drops to just 10 percent at another, P.S. 284.Lorraine Harrigan, 36, told her daughter, Londyn Carroway, a first grader at P.S. 284 in Brownsville, Brooklyn, to keep her mask on.“I feel like they’re rushing too fast to remove the mask,” Ms. Harrigan said.But across the city, Max Shimbo, 14, was one of the few students waiting for the doors to open at Stuyvesant High School not wearing a mask.“I trust the people in the mayor’s office,” he said. “They know how many cases we’re getting and how many people are vaccinated so I trust they made the right choice.’’All students, families, staff and visitors must complete a health screening form before entering a school building each day. And students returning to school from infections will have to wear masks for several days. Masks are also recommended for students and staff who have been exposed to the virus.Monday was a strange day for some students who chose not to wear masks.Dylan DeGaeta, a fifth-grader at PS 1 in Tottenville on Staten Island, said he felt like he was breaking the rules because he had become so used to wearing a mask.“I felt like I was doing something wrong,” Mr. DeGaeta said.Luciana DeRosa, 12, a sixth grader at Independent School 34 in Tottenville on Staten Island was thrilled to have not spent all day behind a mask.“I loved it,’’ she said as she left school. “I get to see everybody’s faces. It felt normal.’’Sadef Ali Kully, Nate Schweber, Julianne McShane, Precious Fondren, Sean Piccoli, Tracey Tully, Sharon Otterman, Emma G. Fitzsimmons, Grace Ashford and Eliza Shapiro contributed reporting.