President Biden, facing mounting pressure on various fronts to gain control of the coronavirus pandemic, placed even more of his administration’s hopes in a “stepped-up” vaccine process, promising Tuesday that there will be enough coronavirus vaccine doses for “every adult in America” by the end of May — a two-month acceleration of his previous projection of July.

Biden said pharmaceutical giant Merck will help make Johnson & Johnson’s one-shot coronavirus vaccine, adding that at the administration’s urging, Johnson & Johnson’s manufacturing facilities will now “operate 24/7.” In the same remarks, the president also said he would use federal authority to offer vaccinations to K-12 teachers and child-care workers, with the aim of getting at least the first shot administered to all educators by the end of March.

Ending the pandemic has been Biden’s top priority since before he took office, and his announcements Tuesday came as his administration is facing myriad setbacks and challenges in combating the virus — and the U.S. pandemic is at an inflection point.

Cases and deaths have steadily and dramatically fallen since January, but the nation’s numbers are now stalled at a worrisome level as more-transmissible variants spread. Federal officials have warned that Americans should remain cautious as the rate of vaccinations continues to rapidly increase.

But states and municipalities nationwide have started abandoning coronavirus restrictions this week, allowing pandemic-weary Americans to shun masks, eat at restaurants without capacity limits and go to entertainment venues.

Texas Gov. Greg Abbott (R) on Tuesday lifted the state’s mask mandate and allowed all businesses to operate at full capacity; Mississippi also lifted most restrictions Tuesday. Governors in numerous states, including Arkansas, Massachusetts, North Carolina and Virginia, loosened restrictions this week.

Texas Gov. Greg Abbott (R) on March 2 lifted most of the state's coronavirus pandemic restrictions, including the mask mandate. (Reuters)

The rush to reopen has alarmed federal health officials, who believe it could threaten important progress in fighting the virus at a fragile time and open the door to another surge this spring.

Biden was also scrambling to make good on a promise he made as president-elect, to reopen the majority of schools by the end of his first 100 days. In using his federal authority to help vaccinate teachers, Biden is hoping to remove one of the major barriers to reopening schools — an urgent step for parents and children alike, but one that has been enormously controversial and complicated.

Teachers, who have resisted going back in many communities, have said they would be much more willing to return to buildings if they are vaccinated first. More than half the states have already put teachers into a high-priority group in their vaccination programs, but others have not.

Biden said that starting next week, the federal government will use its pharmacy program to prioritize educators, allowing them to sign up for vaccination appointments, but he noted that “not every educator will be able to get their appointment in the first week.” The goal, he said, will be for every educator to receive at least one shot by the end of March.

At the end of his remarks, Biden sought to project a sense of optimism when asked by reporters when he thought the nation would return to normal. After saying he had been “cautioned” not to offer such predictions, because of the uncertainty of the virus, he answered with a note of hopefulness: “My hope is by this time next year, we’re going to be back to normal,” the president said.

But some worry that an immediate return to normal could imperil the country’s long-term fight against the virus.

Abbott’s announcement drew immediate condemnation by officials in Houston, Austin and other cities. Houston Mayor Sylvester Turner (D) was in a city council meeting when he was bombarded with text messages about the governor’s actions.

Turner said there was no medical or scientific reason to repeal the mask mandate and lift business restrictions. He noted that hospitalizations in Houston remain high, as does the percentage of people testing positive for the virus.

“Let me just say, this is the wrong direction for the state of Texas, okay?” he said. “And this decision needs to be criticized and condemned by every corner of this state.”

Turner and Harris County Judge Lina Hidalgo sent a letter to Abbott on Tuesday before his announcement, pleading with him not to follow through. Turner said he worries the repeal on masks will especially confuse people at a time when the state cannot afford it.

“We’re saying keep your mask on. The governor and state leadership are saying you can take your mask off,” the mayor said.

Abbott and Mississippi Gov. Tate Reeves (R) cited vaccination efforts and declining case numbers as reasons to lift restrictions, saying government mandates were no longer needed.

“People and businesses don’t need the state telling them how to operate,” Abbott said during a chamber of commerce event, drawing cheers and applause.

Arkansas Gov. Asa Hutchinson (R), who last week lifted nearly all restrictions on businesses, said his state’s mask mandate probably will be rescinded March 31. The public now knows how reduce the spread of the virus, he said during a Friday news conference, and can make those judgments without the state enforcing them.

Meanwhile, Democratic leaders have also been rolling back restrictions, with the governors of Virginia and North Carolina recently ending curfews and increasing capacity limits at certain events starting Monday. Pennsylvania’s governor ended a travel restriction and also raised occupancy limits for gatherings.

In Massachusetts, Gov. Charlie Baker (R) allowed restaurants to operate without capacity limits beginning Monday. Indoor concert halls and recreational venues, such as roller-skating rinks and obstacle courses, can reopen at 50 percent occupancy.

Some cities are resisting Baker’s order. In Boston, officials said they would keep indoor performance and recreational venues closed until later this month. Leaders in Somerville said businesses would remain capped at 25 percent occupancy and gatherings at 10 people.

In Florida, the percentage of cases apparently caused by the B.1.1.7 variant — a more transmissible coronavirus variant first discovered in the United Kingdom — rapidly increased from 2 percent at the beginning of January to more than 30 percent in recent days, according to data from Helix, a company contracted by the Centers for Disease Control and Prevention to increase the nation’s genetic testing. But officials have boasted about the state’s more relaxed measures.

At last week’s Conservative Political Action Conference in Orlando, Republican leaders derided the rules kept in place in other states. Republican Gov. Ron DeSantis described Florida as “an oasis of freedom” in a country beset by “oppressive lockdowns.”

The rolling daily average of U.S. coronavirus cases stood at more than 67,000 on Monday, a 4 percent increase from the week before. Deaths have also flatlined, averaging about 2,000 a day, roughly the same level as the beginning of December.

On Jan. 11, by comparison, the daily average of cases was 248,000 and there was an average of 3,200 deaths per day.

More than 51 million Americans have received at least one dose of vaccine, and vaccine allocations to states are rising to 18 million this week, from 14.5 million last week.

“Now is not the time to relax the critical safeguards that we know could stop the spread of covid-19,” CDC Director Rochelle Walensky said Monday. “We have the ability to stop a potential fourth surge of cases in this country. Please stay strong in your conviction.”

More data in coming days will tell whether the current plateau turns out to be a temporary bump in the road or a more significant derailing of progress. There remains some uncertainty in what the numbers reflect because of a severe winter storm last month that left many Southern states, including Texas and Mississippi, without power and water, disrupting testing and vaccination sites and the ability of health departments to update data.

Jennifer Nuzzo, an epidemiologist with the Johns Hopkins Center for Health Security, said alarm over the plateauing in cases is premature, noting that “in general, one week doesn’t really make a trend.” She said the numbers overall have been positive and that at any rate the decline in cases “might be more like a series of steps” than a week-after-week drop.

“I do think that we are on the path to normalcy,” Nuzzo said. “It’s early on the path, and there’s any number of pitfalls on the way that we would be smart to avoid, including being a little bit too hasty in our reopening. But I am hopeful.”

Hospitalizations offer one piece of good news: They have dropped every day since Jan. 13 except for Feb. 17. There were fewer than 55,000 coronavirus inpatients reported this week, compared with more than 130,000 at the height of the pandemic. Hospitalizations lag cases by several weeks and have not yet flattened in the same way as infections. Experts say vaccination efforts should drive down hospitalization and death numbers in the coming months, as the vaccine helps prevent severe cases.

But many experts remain concerned about the more-transmissible variants circulating in the United States, which they fear could increase cases in the coming weeks. Only about 2,500 variant cases have been detected in the United States, largely because the country has limited capacity to conduct the widespread genetic surveillance needed to identify variants.

A study with updated data from a national genetic sequencing project posted on Sunday shows the B.1.1.7 variant first discovered in Britain is doubling weekly and could become dominant in the coming weeks. As of this weekend it had been found in 46 states.

“We show that the U.S. is on a similar trajectory as other countries where B.1.1.7 became dominant, requiring immediate and decisive action to minimize covid-19 morbidity and mortality,” the study authors wrote in a preprint paper.

Michael Osterholm, who served on the advisory council for Biden during the transition and is not involved in the paper, said data suggests B.1.1.7 could be dominant as in less than two weeks.

“We may have put the very worst of the pandemic behind us, but it doesn’t mean it will get relentlessly better,” said William Hanage, an epidemiologist at Harvard. “With the actions that states are taking now — lifting restrictions just as cases are plateauing — we shouldn’t be surprised in a few weeks if cases start climbing again.”

Nuzzo, despite her optimism, called rescinding mask mandates “a particularly egregious example of what not to do.” She noted that despite weeks of declining cases, the U.S. baseline for cases remains higher than it was in the summer.

Ariana Eunjung Cha and Jacqueline Dupree contributed to this report.