Administering the coronavirus vaccine Tuesday at folding tables spaced throughout the Convention Center, members of the military inoculated federal and SEPTA workers as the city’s first federally run mass vaccination clinic moved toward Wednesday’s grand opening.

Workers left with their first doses as city officials toured the center with Alejandro Mayorkas, secretary of the Department of Homeland Security. Part of a 10-city pilot program through at least April 30 and run in cooperation with the Federal Emergency Management Agency, the clinic is set to inoculate up to 6,000 daily, seven days a week, for the next two months.

“It’s an impressive operation that will go a long way to helping us deliver the vaccine to Philadelphians who actually really need it,” Mayor Jim Kenney said. The site, with vaccine supplied by the federal government and military staffing, is “taking the weight off of us” and “gives us the ability to actually use our own vaccine to get into neighborhoods and to set up sites in the community.”

More vaccine was set to come to the states, too. President Joe Biden announced that the country would have enough doses for all adults by the end of May, in part thanks to planned production of the newly approved Johnson & Johnson doses.

With that highly anticipated, one-shot vaccine on the way, Gov. Tom Wolf said he and his COVID-19 task force had agreed Pennsylvania teachers, most of whom are not eligible in the state’s current phase, should be next in line to get their shots. He is expected to formally announce those plans Wednesday.

Philadelphia independently manages its vaccine distribution and already declared its teachers eligible for inoculation. But the state’s largest teachers’ union and other education groups have been clamoring for teachers statewide to get the vaccine as more schools look to reopen.

Biden on Tuesday directed every state to prioritize educators, telling them in a tweet to ensure every school staff member or child-care worker gets at least one dose by the end of March. New Jersey officials said Monday that teachers there would be eligible on March 15.

Philadelphia Health Commissioner Thomas Farley also confirmed the city would change its restrictions on event crowd sizes to match the new state rules, allowing Philadelphia sports teams to welcome fans back to home games as soon as this weekend.

The city will have to approve teams’ plans — including opening concessions and letting fans eat and drink in the stands, a spokesperson said — before they can bring in fans.

» READ MORE: City will allow about 8,000 Phillies fans into Citizens Bank Park on Opening Day

As case counts and hospitalizations decline in Pennsylvania, New Jersey, and nationwide, the country is balanced on a razor-thin edge, with experts concerned about the potential for a new surge and whether people will be vaccinated fast enough to beat the growing spread of variants.

Officials in this region — and Biden on Tuesday — urged the public to stay committed to safety measures such as mask-wearing and social distancing until the threat of the virus fully recedes, even for people who are vaccinated.

Some areas have pushed to reopen amid the vaccine rollout — the governors of Texas and Mississippi both said Tuesday said they would lift their states’ mask mandates and business restrictions within days — but the Centers for Disease Control and Prevention has recommended against a quick reopening.

Wolf said he agreed with CDC Director Rochelle Walensky that state and local governments should remain cautious, though he also said he was open to reducing limitations on bars and restaurants this spring, and announced $145 million in grant reliefs for Pennsylvania restaurants, hotels, and other hospitality businesses.

“They want to take a little more time to see how this goes, and I agree with that,” Wolf said. “We’re considering everything. The question is how fast can we move in a safe manner to get back to normal.”

Pennsylvania’s new case numbers have plateaued — the seven-day average hovered at 2,612 on Tuesday — halting a steady decline that began in mid-January.

Philadelphia’s health commissioner said it would be a “huge mistake” to ease too many restrictions or to lift the mask mandate.

Farley said he was concerned the city’s progress may be stalling too, saying that a steady rate of new cases over the last two weeks means “we need to be careful.” He said residents must limit interactions and wear masks until more of the population is vaccinated. “Let me put a warning out there,” Farley said. “The increasing number of cases in this region are reason to be concerned.”

In the week that ended Saturday, Farley said, the city had an average of 241 newly confirmed cases per day — compared with 242 the previous week — and a test positivity rate of 3.5%. The city had seen an 80% decrease in the seven-day average of case counts over the last two months.

» READ MORE: Philly’s first federal COVID-19 mass vaccination site already is having to fend off people who aren’t eligible

But the new mass clinic should greatly increase the city’s vaccination capability. On Monday, 284 people were vaccinated in two hours at the first day of the FEMA clinic’s soft launch. The staff aims to do 500 per hour going forward, Farley said, a pace that would hit 6,000 per day with the site operating 12 hours a day, from 8 a.m. to 8 p.m.

The FEMA site offers inoculations by appointment only, and patients will be scheduled through the same process the city uses for appointments at other providers: People must register through the city’s vaccine interest site, then wait for appointment invitations.

A senior adviser for the Pennsylvania Department of Health confirmed that Delaware County would be seeing an immediate increase in doses to fix an undersupply, as first reported by The Inquirer this week. But adviser Lindsey Maudlin said she did not know how big the boost would be and declined to say whether other counties would see similar increases in line with their populations.

Philadelphia, Pennsylvania, New Jersey, and Delaware are scheduled to get Johnson & Johnson doses this week. Officials said initial shipments would be relatively small and it will likely be a few weeks before anyone gets more.

New Jersey said Monday it was expecting 70,000 doses of the new vaccine; Delaware received 8,000 doses Tuesday, said Gov. John Carney. Philadelphia will get 13,200 doses of the vaccine, Farley said.

Because the vaccine is only a single dose, Farley said the city plans to initially give it to providers who can administer it to residents who are homebound, have limited mobility, or are transient because they would not have to return for a second dose.

“We hope in a month we’ll have many more doses of this vaccine,” Farley said, “and we won’t have to be quite so careful about how we distribute it.”

Staff writers Erin McCarthy and Maddie Hanna contributed to this article.