Pink’s Hot Dogs in Los Angeles reopened on Monday after being closed for two months. The restaurant has been in business since 1939.
Credit…Frederic J. Brown/Agence France-Presse — Getty Images

Tens of thousands of students walked into classrooms in Chicago public schools on Monday for the first time in nearly a year. Restaurants in Massachusetts were allowed to operate without capacity limits, and venues like roller skating rinks and movie theaters in most of the state opened with fewer restrictions. And South Carolina erased its limits on large gatherings.

Across the country, the first day of March brought a new wave of reopenings and liftings of pandemic restrictions, signs that more Americans are tentatively emerging from months of isolation, even if not everyone agrees the time is ripe.

There are plenty of reasons for optimism: Vaccinations have increased significantly in recent weeks, and daily reports of new coronavirus cases have fallen across the country from their January peaks.

In Kentucky, all but a handful of school districts are now offering in-person classes, while the state races to vaccinate teachers as quickly as possible. Gov. Andy Beshear told reporters last week that the state’s falling Covid infection statistics showed that immunizations were beginning to make an impact.

“It means vaccinations work,” he said. “We’re already seeing it. We’re seeing it in these numbers. It’s a really positive sign.”

Dr. Anthony S. Fauci, President Biden’s chief medical adviser for Covid-19, said at a news briefing on Monday that for small groups of people who have all been fully vaccinated, there was a low risk in gathering together at home. Activities beyond that, he said, would depend on data, modeling and “good clinical common sense,” adding that the Centers for Disease Control and Prevention would soon have guidance for what vaccinated people could do safely.

The positive signs come with caveats. Though the national statistics have improved drastically since January, they have plateaued in the last week or so, and the United States is still reporting more than 65,000 new cases a day on average — comparable to the peak of last summer’s surge, according to a New York Times database. The country is still averaging more than 2,000 deaths per day, though deaths are a lagging indicator because it can take weeks for patients to die.

New, more contagious variants of the virus are circulating in the country, with the potential to push case counts upward again. Testing has fallen 30 percent in recent weeks, leaving experts worried about how quickly new outbreaks will be known. And millions of Americans are still waiting to be vaccinated.

Given all that, some experts worry that the reopenings are coming a bit too soon.

“We’re, hopefully, in between what I hope will be the last big wave, and the beginning of the period where I hope Covid will become very uncommon,” said Robert Horsburgh, an epidemiologist at the Boston University School of Public Health. “But we don’t know that. I’ve been advocating for us to just hang tight for four to six more weeks.”

The director of the C.D.C., Dr. Rochelle Walensky, said at the briefing on Monday that she was “really worried” about the rollbacks of restrictions in some states. She cautioned that with the decline in cases “stalling” and with variants spreading, “we stand to completely lose the hard-earned ground we have gained.”

The plateauing case levels “must be taken extremely seriously,” Dr. Walensky warned at a briefing last week. She added: “I know people are tired; they want to get back to life, to normal. But we’re not there yet.”

After some counties in Washington State allowed movie theaters to reopen, Nick Butcher, 36, made up for lost time by attending screenings of the “Lord of the Rings” trilogy for three straight nights. He bought some M&Ms at the concession stand, sat distanced from others in the audience, and said he felt as though things were almost back to normal.

“I’m actually getting optimistic, over all,” said Mr. Butcher, a software engineer at Microsoft who recently recovered from a case of Covid-19, as did several relatives. “This week is one of the first times I’ve gone into my office almost since the pandemic started.”

A woman receiving a dose of the Oxford-AstraZeneca vaccine inside a bus modified into a mobile vaccination center in London last month.
Credit…Henry Nicholls/Reuters

A first dose of the Oxford-AstraZeneca vaccine substantially reduced the risk of older people becoming ill with Covid-19, scientists in Britain reported on Monday, the strongest sign yet that a shot that much of the world is relying on to end the pandemic will protect the elderly.

Four weeks after the first dose, the vaccine was roughly 60 percent effective in preventing Covid-19 among people at least 70 years old in England, the scientists wrote in a paper that was posted online on Monday but not yet published in a journal or vetted by other researchers.

That figure appeared to rise in the following week, though there was a high level of statistical uncertainty in the subsequent number.

For countries across Europe that have been hesitant about authorizing the AstraZeneca vaccine for use in older people, the data could resolve some of those doubts. The early clinical trials of the AstraZeneca vaccine did not enroll as many older people as the trials of other shots, making a number of European countries uneasy about using it in that age group.

But Britain decided to authorize the vaccine for people of all ages, creating a valuable store of data on its effectiveness.

In France, one of the countries that had restricted the AstraZeneca vaccine to younger people, the country’s health minister said people over 65 with pre-existing conditions would be able to receive the vaccine, Reuters reported.

In part because of the age restrictions, countries across Europe have been slow to use their doses of the AstraZeneca vaccine, with some health workers holding out for the Pfizer-BioNTech vaccine instead.

The same study from England showed strong protection from the Pfizer vaccine. Among people at least 70 years old, a first dose was 61 percent effective in preventing Covid-19 up to four weeks after the shot, a figure that then plateaued, the study said.

In people at least 80 years old, a first dose was 70 percent effective at preventing Covid-19 four weeks later, a figure that rose to 89 percent two weeks after the second shot. (Britain has decided to delay second doses of both the Pfizer and AstraZeneca shots up to 12 weeks after the first.)

“The results demonstrate that a single dose of either the Pfizer-BioNTech or the Oxford-AstraZeneca vaccine provides a high level of protection against severe disease in the most vulnerable age groups,” Azra Ghani, a professor of infectious disease epidemiology at Imperial College London, said of the findings.

Because Britain authorized the AstraZeneca vaccine later than the Pfizer vaccine, there is less data on the effectiveness of a full two-dose course of the AstraZeneca vaccine.

Both vaccines were also highly effective at preventing coronavirus-related hospitalizations in the study from England.

The study was part of a wealth of data that has emerged from Britain’s mass inoculation program showing that the vaccines were working as intended. No other large nation is inoculating people as quickly as Britain, the first country in the world to authorize and begin using both the Pfizer shot and the one developed by AstraZeneca and the University of Oxford.

School employees welcomed students at Newhall Elementary in Santa Clarita, Calif., last week.
Credit…Marcio Jose Sanchez/Associated Press

California lawmakers and Gov. Gavin Newsom on Monday announced a plan intended to encourage districts to reopen schools, the latest state to take the step that has drawn contentious deliberations across the country.

The agreement includes $2 billion in incentives and fast-tracked vaccinations to lure teachers back for at least some of the remaining school year.

President Biden has pushed for schools to safely reopen, even if that means limited in-person learning, having called for them to be open five days a week, but has been vague about what that would look like. Less than half of students in the United States are attending public schools that offer traditional full-time schedules, frustrating both parents and educators.

In Philadelphia, elected officials, teachers’ unions and health agencies have urged strict caution, putting most districts on hybrid schedules, while some remain fully remote. In the city itself, the teachers’ union and district reached a reopening deal to return students in kindergarten through the second grade to classrooms in phases over the month of March. The city is expediting teacher vaccination and purchasing air purifiers, and hopes to return older students to school before the end of the academic year.

The new schools chancellor in New York City, the largest public school district in the country, pledged on Friday to at least partially reopen high schools by the end of the year. While the city’s schools were among the first in the country to reopen last fall, the in-person learning has been inconsistent because of the virus, and high schools have been closed since November.

The new measures in California come as the state emerges from a towering post-holiday spike in coronavirus cases. The aim is to restore six to 12 weeks of in-person class for the regular school year, which ends in late June in most of the state’s districts. Most of California’s six million schoolchildren have been receiving only remote instruction for the past year.

Rather than mandating reopening, the state will make a time-limited offer of grants to help pay for coronavirus testing, upgraded ventilation and other campus safeguards, along with $4.6 billion for extended class time and summer school.

The money is modest by California standards. The state spent nearly $100 billion last year on its public school system, and the $2 billion pot will be open to more than 1,000 school districts. Those with plans to reopen after March 31 will be eligible for less money, with grants shrinking to zero for schools opening after May 15.

And reopenings are likely to be limited, particularly where the virus and its variants are still surging. In counties with the state’s highest-risk “purple” designation — Los Angeles, for instance — schools will only have to offer face-to-face class for high-needs students and children in transitional kindergarten through second grade to be eligible for reopening money.

In lower-risk counties, districts applying for the grants also will have to offer face-to-face class in elementary schools and at least one middle school and one high school grade.

But the incentives, along with the governor’s promise last week to earmark 10 percent of new first doses of vaccines for school employees, establish California’s clearest blueprint so far for restoring in-person instruction for the bulk of the state’s six million-plus public school students. And they address key demands of the state’s powerful teachers’ unions. Most large districts, including those in Los Angeles, San Diego and San Francisco, have been operating remotely for the vast majority of students for nearly a year.

On Monday, Austin Beutner, the Los Angeles district’s superintendent, said Mr. Newsom had procured enough vaccine doses for its schools to inoculate 40,000 teachers, bus drivers, custodians and other school employees within the next two weeks — enough to reopen Los Angeles classrooms at least through second grade by mid- to late April if school employee unions comply.

Leaders of United Teachers Los Angeles, which represents educators in the nation’s second-largest school district, have asked members to vote this week on a proposed endorsement of their conditions for an in-person return, which include teacher vaccines, stringent health measures and a potential sticking point: a rate of community transmission that is significantly lower than present before schools can reopen.

California school districts need agreements with their unions in order to reopen, although most of the state’s other large districts have already worked out at least a framework for an in-person return.

Long Beach, where city and school district officials have been working together to vaccinate teachers since January, for instance, are on track to resume in-person classes on March 31. And the schools in Elk Grove, near Sacramento, have said elementary students there could be back in classrooms, at least part time, by the middle of this month.

Dana Goldstein contributed reporting.

Emergency medical technicians transported a patient from a nursing home to an emergency room bed at St. Joseph’s Hospital in Yonkers, N.Y., last year.
Credit…John Minchillo/Associated Press

Extraordinarily high staff turnover at U.S. nursing homes most likely contributed to the shocking number of deaths at the facilities during the pandemic, the authors of a new study suggested.

The study, which was published Monday in Health Affairs, a health policy journal, represents a comprehensive look at the turnover rates in 15,645 nursing homes across the country, accounting for nearly all of the facilities certified by the federal government. The researchers found the average annual rate was 128 percent, with some facilities experiencing turnover that exceeded 300 percent.

Researchers pointed to the findings to urge Medicare to publish the turnover rates at individual nursing home sites, as a way of putting a spotlight on substandard conditions and pressuring owners to make improvements.

Inadequate staffing and low pay have long plagued nursing homes and quality of care for the more than one million residents who live in these facilities. But the pandemic has exposed these issues even more sharply, with investigations underway into some states’ oversight of the facilities as Covid-19 cases spiraled unchecked and deaths skyrocketed.

The high turnover rate most likely made it harder for nursing homes to put in place strong infection controls during the pandemic, and led to rampant spread of the coronavirus, said Ashvin Gandhi, the lead author and a health economist and assistant professor at the University of California Los Angeles Anderson School of Management.

Nursing-home owners blame inadequate reimbursement from Medicaid, the federal-state program for elderly skilled nursing care.

“Workforce recruitment and retention is among the most pressing challenges confronting long-term care providers, and we have been calling for help for years,” Dr. David Gifford, the chief medical officer for the American Health Care Association and National Center for Assisted Living, a trade group, said in an emailed statement.

“It’s high past time that providers receive the proper resources to invest in our frontline caregivers in order to improve quality care,” he said.

Credit…Julie Bennett/Associated Press

Nursing home staff members have also shown resistance to getting vaccinated against the coronavirus. If a nurse who was immunized leaves and is replaced, the facility will need to ensure the new employee is also vaccinated, especially given the reluctance of some workers to get a coronavirus shot.

“Trying to do a one-shot vaccination push isn’t enough,” Dr. Gandhi said. “You need continued vaccination outreach.”

People lined up for coronavirus vaccines at the drive-up site at the Walmart store in Lauderdale Lakes, Fla., last week.
Credit…Joe Cavaretta/South Florida Sun-Sentinel, via Associated Press

New York City added workers in the food service and hotel industries to the list of people eligible for coronavirus vaccination on Monday, the same day the governors of Florida and Ohio announced expansions for eligibility in their states.

The expansions come as the supply of vaccines being distributed nationally is ramping up, and after a third vaccine, a single-shot dose from Johnson & Johnson, was authorized for emergency use by the Food and Drug Administration over the weekend. The pace of U.S. vaccinations is again accelerating, up to about 1.82 million doses per day on average, according to a New York Times database, above last month’s peak before snowstorms disrupted distribution.

In New York City, people who work in regional food banks, food pantries and “permitted home-delivered” meal programs became eligible on Monday to receive a vaccine. Hotel workers who have direct contact with guests also became eligible.

The governor of Florida, Ron DeSantis, said on Monday that people 50 and older who work in K-12 schools, law enforcement or firefighting would become eligible on Wednesday. Florida was one of the first states that decided to vaccinate anyone 65 and older, even before most essential workers, which led to long lines and confusion.

Gov. Mike DeWine of Ohio said on Monday that the state would receive more than 448,000 doses this week, including more than 96,000 doses of the Johnson & Johnson vaccine. He said that “in response to this significant increase in the amount of vaccine coming into Ohio,” a new group of people would be eligible on Thursday to get a shot.

That group includes people with Type 1 diabetes, pregnant women and certain workers in child care and funeral services, as well as law enforcement and corrections officers.

To stay ahead of more contagious and possibly more deadly virus variants, states have been racing to ramp up vaccinations and expand eligibility. But they have often done so before the supply could increase quickly enough, creating shortages and making it harder for people to get vaccination appointments.

Screening for the coronavirus at the University of Idaho in Moscow, Idaho, last week. The volume of testing in the United States has fallen by 30 percent since January.
Credit…Rajah Bose for The New York Times

Widespread testing is crucial in controlling the spread of the coronavirus and squashing new outbreaks, experts say. But the amount of testing in the United States has fallen by 30 percent in recent weeks.

From a high of nearly 14 million tests a week in early January, the pace fell to fewer than 10 million — a level not seen since October —  in the week ended Feb. 24, according to the Covid Tracking Project.

Some areas report even sharper declines: Michigan is testing about half as many people now as it was in November, and Delaware’s state-run sites are testing about one-third as many. Los Angeles County’s sites, which were running flat out last month, tested just 35 percent of their capacity last week.

Experts cited a number of factors that could be contributing to the slump:

  • Fewer exposures. Since daily tallies of new coronavirus infections have fallen sharply, fewer people may be having contacts that would prompt them to seek a test.

  • Less travel. The holiday rush is over, reducing the need for people to get tested before or after trips.

  • Bad weather. The severe storms and Arctic temperatures that battered much of the country, from Texas to the Northeast, caused many testing sites to close temporarily.

  • The vaccine rollout. Some states have shifted their limited public health resources, and their public messaging, toward vaccination efforts at the expense of testing.

  • Pandemic fatigue. Some experts worry the decline may be yet another symptom of public exhaustion and frustration with pandemic precautions and safety measures.

All those forces may be at play, said Dr. Jennifer Nuzzo of the Johns Hopkins Bloomberg School of Public Health: “My sense is that it’s probably that there are fewer options for testing, fewer communications about it, people may be perceiving that it’s less necessary — maybe they just don’t see the point any more.”

The slump in testing, at a time when a clear picture of the pandemic is still badly needed, worries some epidemiologists. “There’s nothing about the current situation that has made testing any less necessary,” Dr. Nuzzo said.

Among other things, less testing makes it harder to follow the virus’s mutations and to get ahead of variants that may be more contagious or deadly, said Dr. Rick Pescatore, the chief physician at the Delaware Division of Public Health. “We can’t identify variants until we first identify positives.”

But the decline in testing may not be a cause for alarm — and may even be a good sign — if it reflects wider progress in tamping down the pandemic, said Dr. Clemens Hong, who runs Los Angeles County’s testing program.

“The biggest reason for the drop in testing demand, I think, is the decrease in infections and spread,” Dr. Hong said. “Covid-19 is not spreading as quickly right now, which means there’s fewer people with symptoms, and also fewer people having contact with people with Covid-19. That’s just the reality.”

Across the country, new case reports have dropped sharply since mid-January. At its peak on Jan. 8, the U.S. reported a seven-day average of over 259,000 new cases. Now, the seven-day average is less than 70,000, as of Saturday.

Hospitalizations and deaths have followed suit, and vaccine distribution is rapidly increasing: 15 percent of the U.S. population has now received at least one dose.

Nonetheless, Dr. Hong said, testing remains vital to getting ahead of outbreaks.

“Even with all these declines and the rollout of the vaccines, it’s just not enough,” he said. “We don’t have enough immunity in the community to prevent another surge. We may never see a surge like we saw in December and January again, but we’ll see little pockets and little surges that will try to come to life, and we just need to put them out.”

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Johnson & Johnson said it would start shipping millions of doses early this week after the Food and Drug Administration granted emergency use authorization for its vaccine on Saturday.CreditCredit…Pool photo by Timothy D. Easley

When Johnson & Johnson’s coronavirus vaccine won emergency use authorization on Saturday from the Food and Drug Administration, the move augmented the nation’s vaccination effort with a third major tool — one that differs markedly from the first two authorized vaccines, made by Pfizer-BioNTech and Moderna.

Most notably, it is administered in a single dose instead of two, and can be kept unfrozen in an ordinary refrigerator for up to three months — features that promise greater flexibility as public health officials try to immunize Americans as quickly as possible.

Much is still to be determined about how this new tool will be used. Here is what we know so far.

Within the next few days. Johnson & Johnson started shipping out doses on Monday, and they can be used as soon as they reach vaccination sites starting on Tuesday.

At first, the increase in availability will be limited. The company had about 3.9 million doses on hand to ship right away, but after that, deliveries could be patchy for a few weeks. (For comparison, the nation is using up that many doses of the Pfizer-BioNTech and Moderna vaccines in a little more than two days.)

By the end of March, Johnson & Johnson says it will ship roughly 16 million more doses. Even so, the Pfizer-BioNTech and Moderna vaccines will continue to make up the majority of the nation’s supply.

The same way the two earlier vaccines are: in proportion to each state or territory’s population.

That’s still under discussion. The Centers for Disease Control and Prevention has said that the vaccine can be given to people 18 and over, and state officials are working out what their policies will be.

Because the new vaccine is given in a single shot and doesn’t require cold storage, some experts and officials have suggested directing it toward hard-to-reach segments of the population (like rural residents or homeless people), or to people who might not keep an appointment for a second shot (like college students or those with mobility issues).

But there is concern about appearing to favor or disfavor some groups, and the Biden administration has said it will insist that the new vaccine be distributed equitably.

That’s not clear. Right now, people are getting whichever vaccine the site has on hand when their turn comes, and appointment scheduling systems generally don’t tell users beforehand which it will be. Depending on how states decide to deploy the Johnson & Johnson vaccine, though, it may be possible to effectively choose what you get by choosing where you sign up to get it.

Health experts say the best shot is the one you can get the soonest, whichever one it turns out to be. All three authorized vaccines are highly protective, and the differences among them pale in comparison, they say, with the risk you would run by being picky and passing up a chance to get a shot because it was not your top choice.

Frontier Airlines is facing accusations of anti-Semitism for its treatment of the passengers, who are Hasidic Jews.
Credit…Tony Dejak/Associated Press

A Frontier Airlines flight from Miami to La Guardia Airport in New York was canceled on Sunday night after a large group of passengers, including several adults, refused to wear masks, the airline said.

By Monday morning, the airline was facing accusations of anti-Semitism for its treatment of the passengers, who are Hasidic Jews, as well as demands for an investigation from the Anti-Defamation League of New York and other groups. Frontier steadfastly held to its position that the passengers had refused to comply with federal rules requiring them to wear masks.

Several phone videos that have surfaced do not show the confrontation that took place between the passengers and the Frontier crew members, only the aftermath. The video footage from inside the aircraft appeared to show members of the group wearing masks. Some passengers said that the episode escalated because just one member of the group, a 15-month-old child, was not wearing one.

Videos of the passengers exiting the plane amid chaos, captured by other people on the flight, were posted on Twitter by the Orthodox Jewish Public Affairs Council. In one video, a passenger says, “This is an anti-Semitic act.”

Another video showed a couple holding a maskless baby in a car seat, as children could be heard crying and a woman explained that the young children in their group, sitting in the back of the plane, had taken off their masks to eat.

A Frontier Airlines spokeswoman said in a statement that “a large group of passengers repeatedly refused to comply with the U.S. government’s federal mask mandate.”

GLOBAL ROUNDUP

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On Monday, Prime Minister Narendra Modi of India was vaccinated against the coronavirus. The country is beginning a large inoculation effort using the Oxford-AstraZeneca and the Covaxin vaccines.CreditCredit…India’s Press Information Bureau, via Reuters

NEW DELHI — Prime Minister Narendra Modi of India was vaccinated against the coronavirus on Monday as the country began the next phase of its inoculation drive, one of the largest in the world.

India has approved two coronavirus vaccines for emergency use: the Oxford-AstraZeneca vaccine, which is produced by the Serum Institute of India, the world’s largest vaccine producer; and Covaxin, which was developed by Bharat Biotech, an Indian pharmaceutical company.

Mr. Modi received the first of two doses of Covaxin, in line with his pitch for a “self-reliant India,” which he reiterated in his monthly radio address over the weekend. “The first condition for self-reliance is to have pride in the things of one’s own country,” he said.

Mr. Modi’s appeal to “make India Covid-19 free” comes at a time when vaccine hesitancy in the country is high, with 58 percent of respondents in one survey expressing doubts. India has managed to inoculate only about 14 million of its 1.3 billion people since its inoculation drive began this year.

As of Monday, vaccine eligibility in India has been expanded to include anyone 60 and older, as well as people 45 and older with chronic conditions such as heart disease, diabetes and hypertension.

Last month, India appeared to be experiencing something of a breather in its outbreak. The country has registered more than 11.1 million total cases, the second-highest tally in the world, after that of the United States, according to a New York Times database. Cases are again increasing.

On Sunday, the chief minister of the state of Maharashtra, which includes the country’s financial capital, Mumbai, imposed a lockdown in some areas after cases there surged.

In other global developments:

  • As most of Italy struggles to fight back coronavirus infections, the authorities on the island of Sardinia on Monday all but lifted restrictions. For the first time in months, locals will be able to eat in restaurants at night and stay outside past 10 p.m. Masks and social distancing will still be mandatory. Christian Solinas, the region’s president, said it was “a great result reached thanks to the sacrifices of all Sardinians.”

  • The Czech Republic, which is enduring one of the world’s worst coronavirus outbreaks, rolled out new restrictions on Monday limiting travel and closing schools, Reuters reported. About 26,000 police officers and 3,800 soldiers were deployed to enforce the orders.

  • The first doses distributed through the Covax program, which focuses on providing the vaccine to lower-income countries, were administered in Ghana and Ivory Coast on Monday, the World Health Organization said. The president of Ghana, Nana Akufo-Addo, and his wife received the shot at a military hospital, saying on Twitter that the vaccine — branded Covishield and developed by Oxford University and AstraZeneca — is safe and “a major catalyst to restoring livelihoods.”

  • Colombia on Monday became the first country in the Americas to receive a shipment of vaccines through the Covax program. That delivery was part of a “first wave” initiative that gives some countries an “early delivery of a limited number of doses” of the vaccine developed by Pfizer and BioNTech, the World Health Organization said.

  • The Philippines, which has had one of the worst coronavirus outbreaks in Southeast Asia, began its inoculation campaign on Monday even as the government struggled to reassure a population wary of foreign-made vaccines. The Philippines, a nation of more than 100 million, is among the last Southeast Asian countries to receive any coronavirus shots but aims to vaccinate 70 million people this year.

  • After months of coronavirus restrictions, a surge of shaggy-haired customers in Germany were able to walk into hair salons and barber shops — some of which opened their doors at 12:01 a.m. with champagne and confetti to celebrate the reopenings. Other stores, like nurseries, flower shops and nail salons, were also allowed to reopen on Monday, but all must adhere to strict rules on social distancing and mask wearing.

  • The health minister of Somalia on Monday proposed closing all schools and universities, as well as doubling down on other measures like social distancing and prohibiting large gatherings, as the country faces a worsening outbreak amid an impasse over elections.

  • Officials in Britain were frantically searching on Monday for someone who tested positive for the coronavirus variant first detected in Brazil. The person’s identity and whereabouts were a mystery: The person neglected to fill out an information card that accompanied a test kit, sending British officials on a quest to use postal service data to track them down.

Former President Donald Trump and former First Lady Melania Trump before boarding Air Force One for his last time as President on January 20, 2021.
Credit…Pete Marovich for The New York Times

Former President Donald J. Trump and his wife, Melania, quietly received coronavirus vaccinations in January before leaving the White House, an adviser said on Monday.

The news came a day after Mr. Trump appeared at the CPAC political conference in Orlando, Fla., where for the first time he encouraged people to go get vaccinated.

“Everyone should go get your shot,” Mr. Trump said during the speech. When The Times asked an adviser to the former president whether he had received his, the answer was that he had, in private, a month earlier.

The secret approach by Mr. Trump came as a number of his supporters have expressed resistance to the vaccine, and as other officials have tried setting an example by getting the shot in public.

President Biden, Vice President Kamala Harris and former Vice President Mike Pence received vaccine shots in front of television cameras.

Mr. Trump’s concern about the vaccine has generally been about whether he is getting credit for its development while he was president. He never publicly encouraged people to take it while he was in office; the first vaccines were approved shortly after Election Day.

The adviser did not say whether Mr. Trump received both his first and second shots of the vaccine in January, or if the second one was at another time.

Mr. and Mrs. Trump were both infected with the coronavirus in the fall, and the former president was hospitalized with a severe case.

Health care workers in the Covid-19 Unit at United Memorial Medical Center in Houston.
Credit…Mark Felix/Agence France-Presse — Getty Images

Every coronavirus variant of concern to researchers around the world has been circulating in Houston at a low level for at least six to eight weeks, a new study has found. Houston is the first U.S. city to find all of the variants, including those recently reported in California and New York and the ones found in Brazil, Britain and South Africa.

The discovery mainly highlights how little is actually known about the variants — their true whereabouts, prevalence and impact — as no other American city has the data in place to make such a survey possible.

Since last March, a team of researchers led by Dr. James Musser, chair of the department of pathology and genomic medicine at Houston Methodist Hospital, have been sequencing the viral genomes drawn from patients — 20,000 genomes so far.

Dr. Musser said the team had also analyzed detailed information on the infected patients. By linking the data sets, scientists can begin to ask vital questions: How do these variants affect the ability of the virus to spread, if at all? Do they make the symptoms any more or less severe? Are they any more or less resistant to vaccines, pre-existing immunity or treatment with monoclonal antibodies?

Before the pandemic took off in Houston, the team had set up a plan to match any variant it found with the clinical course of patients infected with it.

“If you don’t have the sequencing matched up with patient data, they are far, far less interesting, if not uninterpretable,” Dr. Musser said.

To Dr. Musser’s knowledge, Houston is the only city with the patient and sequencing data to address those questions. Iceland is undertaking a similar effort, he said, and he expects Israel to do so, also.

So far, researchers have tried to infer the effect of variants by looking at their prevalence in different populations and by doing laboratory studies. Those can provide important clues, Dr. Musser said, but to make the best use of those data, they must be linked to patient data.

Some critics, including Dr. Eric Topol, the founder and director of the Scripps Research Translational Institute, have said that the attention given to the succession of new variants — “scariants,” he has called them — has done little more than frighten the public.

Dr. Musser agreed, referring to such reports as “mutant porn.” Highlighting the existence of variants without indicating whether they make any functional difference to real-world patients was no more enlightening than collecting stamps or identifying the birds flying overhead, he said: “‘There’s a bird. There’s another bird.’”

He added: “I think the crucial thing in all of this is that it is extraordinarily difficult for both the medical and lay public to really sort through all this noise about variants. At the end of the day, does any of this mean a hill of beans to anyone?”

“The big issue is to try to get things toned down.”

Vaccines were prepared at a community center in Rohnert Park, Calif., in January.
Credit…Jim Wilson/The New York Times

Coronavirus vaccinations can cause enlarged lymph nodes in the armpit or near the collarbone, which may be mistaken for a sign of cancer.

Doctors are seeing more and more of these swollen nodes in recently immunized people, and are trying to allay fears and help patients avoid needless testing for a harmless condition that will go away in a few weeks.

The swelling is a normal reaction by the immune system, and occurs under the arm where the shot was given. Patients may not notice it. But it shows up on mammograms and other scans, resembling images that can indicate the spread of cancer from the breast or elsewhere in the body.

“I am particularly eager to get the word out to all the patients undergoing surveillance after successful prior treatment of cancer,” said Dr. Constance D. Lehman, an author of two journal articles on the problem and the chief of breast imaging at the Massachusetts General Hospital. “I can’t imagine the anxiety of getting the scan and hearing, ‘We found a node that is large. We don’t think it’s cancer but can’t tell,’ or worse, ‘We think it might be cancer.’”

Dr. Lehman said imaging centers should ask patients if they have had Covid-19 inoculations and record the date of the shot and the arm in which it was given.

Her clinic includes this advisory in a letter to patients whose screenings detect swelling but no other abnormalities: “The lymph nodes in your armpit area that we see on your mammogram are larger on the side where you had your recent Covid-19 vaccine. Enlarged lymph nodes are common after the Covid-19 vaccine and are your body’s normal reaction to the vaccine. However, if you feel a lump in your armpit that lasts for more than six weeks after your vaccination, you should let your health care provider know.”

One way to avoid the problem would be to postpone routine mammograms and other imaging for at least six weeks after the last dose of vaccine, according to an article by an expert panel in the journal Radiology.

But the panel also cautioned that nonroutine imaging, needed to help deal with an illness or other symptoms that might indicate cancer, should not be delayed. Nor should immunization.

In recently vaccinated people who have cancer and develop enlarged lymph nodes, it may be necessary to perform more tests, including a biopsy of the nodes, Dr. Lehman said.

The vaccines already in wide use in the United States are given in two doses several weeks apart, while the newly authorized Johnson & Johnson vaccine is given in a single dose.
Credit…Pool photo by Timothy D Easley

A third effective weapon was added to America’s arsenal against the coronavirus on Saturday when the Food and Drug Administration granted emergency use authorization for a vaccine developed by Johnson & Johnson.

The company said it would start shipping millions of doses early this week, and would provide the United States with 100 million doses by the end of June. Together with 600 million doses of the nation’s first two authorized vaccines, made by Pfizer-BioNTech and Moderna, that are due to be delivered over the next four months, that ought to be enough to cover every American adult who wants to be vaccinated.

The new vaccine differs markedly from the two already in use in the United States. Here is how they compare.

The Johnson & Johnson vaccine is administered in a single shot, while the Pfizer-BioNTech and Moderna vaccines are given in two shots several weeks apart.

The Johnson & Johnson vaccine uses a different method to prime the body to fight off Covid-19: a viral vector called Ad26. Viral vectors are common viruses that have been genetically altered so that they do not cause illness but can still cause the immune system to build up its defenses. The Pfizer-BioNTech and Moderna vaccines use messenger RNA to do that.

The Johnson & Johnson vaccine is rated as highly effective at preventing serious illness and death, as the Pfizer-BioNTech and Moderna vaccines are. It is also very effective at preventing milder illness, though a bit less so than those two. It appears to do well against the highly contagious B.1.351 variant, first identified in South Africa, that has given at least one other vaccine candidate trouble.

The Johnson & Johnson vaccine does not have to be stored at extremely low temperatures like the Pfizer-BioNTech vaccine. It can safely be kept in an ordinary refrigerator for three months, much longer than the Moderna vaccine, which spoils after a month if not kept frozen.

The Johnson & Johnson vaccine appears to be less prone than the Pfizer-BioNTech and Moderna vaccines to trigger the kinds of side effects that require monitoring after the injection, which may make it more suitable for use at drive-through vaccination sites. There have been reports that side effects tend to be felt more strongly after second doses, which the Johnson & Johnson vaccine does not require.

As U.S. Begins to Reopen, Some Officials Worry It’s Too Soon 1

As the pandemic wrought economic devastation around the country, states were forced to revise their revenue forecasts and prepare for the worst, but new data shows that, for many, the worst didn’t come. One big reason: $600-a-week federal supplements that allowed people to keep spending — and states to keep collecting sales tax revenue — even when they were jobless, along with the usual state unemployment benefiIn Washington, lawmakers disagree on whether states should get no-strings-attached federal aid — an issue that has long been a stumbling block for state and local governments receiving a direct infusion of cash from Congress. President Biden’s $1.9 trillion federal stimulus bill contains $350 billion in relief for state, local and tribal governments and a $400 weekly unemployment supplement.

Republicans have mostly said no to this kind of federal aid, casting it as a bailout for spendthrift blue states. Democrats have argued the opposite, saying that states face dire fiscal consequences without aid.

By some measures, states in the past year ended up collecting nearly as much revenue in 2020 as they did in 2019. A J.P. Morgan survey called 2020 “virtually flat” with 2019, based on the 47 states that report their tax revenues every month, or all except Alaska, Oregon and Wyoming. And a researcher at the Urban-Brookings Tax Policy Center, a nonpartisan think tank, found that total state revenues from April through December were down just 1.8 percent from the same period in 2019.

In short, the states struggled far less during the pandemic than in previous recessions. During the Great Recession, Congress sent supplements of just $25 a week. This time, Washington sent supplements of $600 a week. Since the pandemic ravaged low-wage sectors like retail sales and restaurants, adding $600 a week to the lowest unemployment benefits pushed many recipients’ purchasing power above what they had while working.

Emily Cochrane contributed reporting.

Ursula von der Leyen, the president of the European Commission, speaking at a press conference at the end of a European Union summit in Brussels on Friday.
Credit…Pool photo by Johanna Geron

The European Union will propose issuing a certificate called a Digital Green Pass that would let people who have been vaccinated against the coronavirus travel more freely, Ursula von der Leyen, the president of the European Commission, said on Monday.

“The Digital Green Pass should facilitate Europeans’ lives,” Ms. von der Leyen wrote on Twitter. “The aim is to gradually enable them to move safely in the European Union or abroad — for work or tourism.”

The announcement followed an intense debate at a virtual meeting last week that laid bare deep divisions among leaders of the bloc’s 27 member nations.

Tourism-dependent nations like Greece have been pushing for such a plan to help salvage the summer travel season, while others, led by France, have been wary of the potential for discrimination between vaccinated and non-vaccinated Europeans, as well as possible infringement on personal data protection.

“In the future, it will certainly be good to have such a certificate, but that will not mean that only those who have such a passport will be able to travel,” Chancellor Angela Merkel of Germany said after the meeting last week.

Vaccination efforts in the European Union have generally gotten a sluggish start. Just 5 percent of the bloc’s population has received at least one shot of vaccine so far. But the certificates will go beyond vaccination status to include the holder’s wider medical history concerning the virus, according to Christian Wigand, the commission’s spokesman.

“We will also be looking at other categories of information to avoid discrimination of citizens, such as test results and statements of recovery,” Mr. Wigand said on Monday.

Getting the system set up and issuing certificates would take at least three months, the commission said. It was not immediately clear what legislative and technical steps would be required, nor whether the system would extend beyond European Union citizens.

The commission said there should be a way to scale it up globally, in cooperation with the World Health Organization. But when pressed for further details, Mr. Wigand asked for “a little bit of patience,” explaining that “this is all very fresh.”

After the meeting with the 27 national leaders last week, Ms. von der Leyen said: “It is important to have a European solution, because otherwise others will go into this vacuum. Google and Apple are already offering solutions to the W.H.O., and this is sensitive information.” Apple said afterward that Ms. von der Leyen may have misunderstood and that the company was not currently offering such a solution.