New York and its neighbors New Jersey and Connecticut announced on Monday that they were lifting almost all their pandemic restrictions, paving the way for a return to fuller offices and restaurants, a more vibrant nightlife and a richer array of cultural and religious gatherings for the first time in a year.

The relaxation of rules starting May 19 is a testament to the fact that coronavirus cases are down and vaccination rates are rising, offering a chance to jump-start the recovery in a region that became a center of the global pandemic last spring.

New York will also bring back 24-hour service to the subway on May 17, after a year of overnight closures, a move critical for night-shift workers and a symbolic boost to a city that takes pride in a transit system that had, until the pandemic, never closed for extended periods.

“Today is a milestone for New York State and a significant moment of transition,” said Gov. Andrew M. Cuomo, who made the announcement in tandem with the governors of the two other states, reflecting how the region has tried to coordinate its response to the public health emergency.

Mr. Cuomo, in announcing the sweeping changes, sought to accelerate New York’s rebound and coax back workers and tourists vital to the city’s economy and its dynamism. Last week, Mayor Bill de Blasio had set a goal of July 1 for fully reopening the city.

But public health experts warned that the officials might be taking too big a risk in opening so widely so soon given the lagging rates of vaccination among some age groups and in certain parts of the city, and the spread of more contagious variants.

NYC & Company, the city’s tourism-promotion agency, however, lost no time in spreading word of the loosening restrictions.

“We are open for business and the city is reawakening,” said Chris Heywood, an agency spokesman. “The summer holds considerable promise for us. People are clamoring to make up for a year of lost vacation time.”

As the three states made their announcement, there were other signs that the nation was turning the corner in the fight against Covid-19. Significantly, the Food and Drug Administration was said to be moving toward authorizing the Pfizer-BioNTech vaccine for children 12 to 15 years old by next week.

For many business owners, especially in the hospitality industry, news of the reopening was a lifeline.