As scientists and government officials wrestle with variants of the coronavirus that were first detected in Britain and South Africa, Prime Minister Boris Johnson of Britain is expected to announce an extension and tightening of lockdown rules in England, while President Biden plans to bar travel by noncitizens into the United States from South Africa.
A White House official, citing concern over the variants, said on Sunday that the South Africa ban would go into effect on Jan. 30 and that a ban would be extended on noncitizen travelers from Europe and Brazil — the same ban that former President Donald J. Trump, on his last full day in office, tried to eliminate.
The variants are just two of several emerging across the globe that have scientists asking how well coronavirus vaccines will hold up. Studies published last week show that the variant identified in South Africa is less susceptible to the antibodies created by natural infection and by the vaccines made by Pfizer-BioNTech and Moderna, which have both been authorized for emergency use in the United States, the European Union and elsewhere. Those vaccines can be altered in a matter of weeks, but experts warn that it would be difficult to update them constantly.
The vaccines held up against the British-affiliated variant in one study. But at a news briefing in London on Friday, Mr. Johnson said that the variant was not only more contagious but may also be more deadly.
He is expected to announce that schools may stay closed until Easter, which this year falls on April 4, while travelers arriving in Britain could be required to quarantine in hotels for 10 days.
While scientists agree that the evidence of the so-called British variant’s greater lethality is preliminary, inconclusive and based on limited data, they said it nonetheless served the government’s purposes in the debate over lockdowns, in which Mr. Johnson, pulled between science and politics, has often shown an aversion to taking hard steps.
“It’s odd to be making such an announcement, which has serious implications and is clearly concerning for the general public, without having a full data set and a more thorough analysis,” said Lawrence Young, a virologist at Warwick Medical School. “I wonder whether it was about reinforcing the tough message about needing to stick to lockdown and justifying increased border controls.”
The Centers for Disease Control and Prevention recently warned the so-called British variant could become the dominant source of infection in the United States by March and would very likely lead to further surges in cases and deaths.
The agency announced a new policy that requires all arriving international air passengers, regardless of vaccination status, to be tested for the coronavirus within three days of their departure for the United States, and to provide written documentation of their test results or proof of having recovered from Covid-19, the disease caused by the coronavirus.
Mr. Biden, despite vowing to quickly re-engage with the world and retracting a decision by the Trump administration to withdraw from the World Health Organization, has now been forced to seal the country off from much of it.
China’s coronavirus vaccines were supposed to deliver a geopolitical win that showcased the country’s scientific prowess and generosity. Instead, in some places, they have set off a backlash.
Officials in Brazil and Turkey have complained that Chinese companies have been slow to ship the doses and ingredients. Disclosures about the Chinese vaccines have been spotty. The few announcements that have trickled out suggest that China’s vaccines, while considered effective, cannot stop the virus as well as those developed by Pfizer and Moderna, the American drugmakers.
In the Philippines, some lawmakers have criticized the government’s decision to purchase a vaccine made by a Chinese company called Sinovac. Officials in Malaysia and Singapore, which ordered doses from Sinovac, have had to reassure their citizens that they would approve a vaccine only if it has been proven safe and effective.
At least 19 countries, most of them low and middle income, signed deals with the Chinese vaccine companies because they offered access at a time when richer nations had claimed most of the doses made by Pfizer and Moderna. But the delays in getting the Chinese vaccines and the fact that the vaccines are less effective mean that those countries may take longer to vanquish the virus.
Beijing officials who had hoped the vaccines would burnish China’s global reputation are now on the defensive. The state news media has started a misinformation campaign against the American vaccines and promoting the Chinese vaccines as a better alternative. They have also distributed online videos that have been shared by the anti-vaccine movement in the United States.
The vaccines are also meant to prove that China has become a scientific and diplomatic powerhouse. It remains on par with the United States in the number of vaccines approved for emergency use or in late-stage trials. Sinopharm, a state-owned vaccine maker, and Sinovac have said they can produce up to a combined two billion doses this year, making them essential to the global fight against the coronavirus.
Unlike the Pfizer and Moderna vaccines, their doses can be kept at refrigerated temperatures and are more easily transported, making them appealing to the developing world.
China’s campaign has been plagued with doubts, however. A YouGov survey this month of roughly 19,000 people in 17 countries and regions showed that most were distrustful of a Covid-19 vaccine made in China. The misinformation campaign surrounding Western vaccines could further undermine its image.
Mexico’s president, Andrés Manuel López Obrador, said Sunday that he had contracted the coronavirus and was undergoing “medical treatment” for what he described as mild symptoms.
Mr. López Obrador, writing on Twitter, said he would continue to carry out his official duties, including holding a call with President Vladimir V. Putin of Russia that is set for Monday.
“As always, I am optimistic,” he said.
The Mexican leader has consistently played down the pandemic, questioning the value of wearing masks and refusing to wear one himself in most public appearances.
On Friday, he posted a photo of himself indoors, again without a mask, conducting a call with President Biden. He was accompanied by Marcelo Ebrard, the foreign minister, and Alfonso Romo, a former top aide — and neither was wearing a mask. And on Saturday, the president met with local business leaders in Monterrey.
Hours before disclosing that he had contracted the virus, Mr. López Obrador, who flies commercial on all official trips, sat in coach on a flight from San Luís Potosí to Mexico City, according to local media reports.
As late as June, Mr. López Obrador was still sounding dismissive. He said that having a clean conscience would help fight off the virus. “No lying, no stealing, no betraying, that helps a lot to not get coronavirus,” he told reporters.
And for months, the president has repeatedly insisted that the end of the pandemic’s devastation was just around the corner.
“The worst is ending,” he said this month, as deaths surged. “We are coming out of it.”
In the spring, The New York Times reported that the Mexican government had failed to record hundreds, possibly thousands, of deaths in Mexico City, dismissing officials who had tallied more than three times as many fatalities in the capital than the government had publicly acknowledged.
Then in December, federal officials, loath to damage the economy still further, reassured the public that Mexico City had not reached the level of contagion that would require a full lockdown. In fact, the government’s own numbers showed that the capital had surpassed that threshold, an analysis by The Times found.
Some public health experts said they were little surprised that Mr. López Obrador had become infected, given his preference for going mask free, even in situations where the risk of exposure was high.
“One even expected or assumed, because of his way of exposing himself to so many people and not wearing a mask, that he would have been infected earlier,” said Carlos Magis Rodríguez, professor of medicine at the National Autonomous University in Mexico. “In all the public appearances of López Obrador, except for when he went to visit Trump, we saw him without a face mask.”
He said there was reason for concern about the prognosis for Mr. López Obrador, who is 67 and had a heart attack in 2013. “He’s at greater risk than a young person,” Dr. Magis said.
Mr. López Obrador has told reporters that he will wait to get vaccinated with the rest of his age group, most likely in mid-March.
The news came as Mexico is confronting its worst moment since the pandemic began, with deaths hitting horrific highs. On Thursday, Mexico confirmed 1,803 new coronavirus deaths, surging past the previous record of more than 1,500 set days earlier.
And while the president is already being treated, many Mexicans are struggling to get medical care. The country’s hospitals are overrun, and close to 90 percent of beds in Mexico City, the epicenter of the national outbreak, are occupied.
Mexico has intentionally kept testing low throughout the pandemic, which has obscured the true extent of the virus’s reach across the country. But it is undeniable that Mr. López Obrador has presided over one of the worst outbreaks in the world.
To date, the country has recorded more than 1.7 million coronavirus infections and nearly 150,000 deaths, the fourth-highest global death toll.
Official numbers severely underestimate the true toll of the pandemic. As of December, the country had recorded 250,000 more deaths than expected, an excess mortality rate that suggests the pandemic has been far deadlier than official numbers suggest.
Kirk Semple and Elda Cantú contributed reporting.
An adviser to seven presidents and the nation’s top infectious disease expert for decades, Dr. Anthony S. Fauci has weathered many crises.
But in 2020, as one of the most familiar, trusted faces of the nation’s public health community, Dr. Fauci, 80, faced a year like no other when the coronavirus pandemic unfolded in the final months of the Trump administration amid an extremely divisive election season.
In an hourlong conversation with The New York Times over the weekend, Dr. Fauci described some of the difficulties, and the toll, of working with President Donald J. Trump.
Carolyn Zain had heard horror stories about the nation’s coronavirus vaccine rollout: long waits, clunky websites, people being turned away. So when her health department announced it was expanding appointments, she armed herself with two phones and held her breath.
Within 20 minutes, she secured a slot for the next day. She arrived for her 2 p.m. appointment and was resting in a chair, a fresh shot in her arm, by 2:21 p.m.
“It went wonderfully,” said Ms. Zain, 79, who, after a year spent mostly home alone, wore a sequined face mask that shimmered like confetti for her appointment at a Charleston clinic last week.
Since the United States began distributing vaccines more than a month ago, it has moved far more slowly than officials had hoped. But West Virginia has stood out for its success in getting people vaccinated. About 9 percent of all West Virginians have received a first dose of the coronavirus vaccine, a larger segment than in every state but Alaska and double the rate of some.
No state has given a larger share of its residents second doses, a crucial step to securing the best chance at immunity.
While many states are struggling to hand out the shots that the federal government has provided to them, West Virginia has given out 83 percent of its doses, by far among the highest. Many states so far have struggled to give even half of their allotted vaccines.
“West Virginia is about at the top of the charts,” said Dr. Mark McClellan, a former commissioner of the U.S. Food and Drug Administration. “We need to get more states to the point that they have the vaccination capacity of West Virginia.”
The state also provides a glimpse at a fundamental problem that looms for the country: Even the most efficient state vaccine operations do not have enough shots for all who want them.
Dr. Clay Marsh, the state coronavirus czar, estimated that West Virginia had the capacity to handle 125,000 doses a week, but was getting just 23,600.
Early on, the state got a significant head start because it initially opted out of a federal program to vaccinate people in nursing homes and other long-term care facilities.
The federal plan teamed up with Walgreens and CVS to inoculate people in nursing homes around the country, but many communities in West Virginia are far from the nearest big box store, and about half of pharmacies are independently owned.
West Virginia created a network of pharmacies in the state, pairing them with about 200 long-term care facilities. As a result, West Virginia finished its first round of vaccinations at nursing homes last month, while many states were just getting started.
Central to the state’s strategy, too, is putting the National Guard at the helm of vaccine operations.
Officials say they have also learned what not to do, including not promising shots they do not yet have. In Charleston, appointments are not made until county officials have that week’s allotment of vaccines on hand, sitting in their own freezer.
In his first 48 hours in office, President Biden sought to project an optimistic message about returning the nation’s many homebound students to classrooms. “We can teach our children in safe schools,” he vowed in his inaugural address.
The following day, Mr. Biden signed an executive order promising to throw the strength of the federal government behind an effort to “reopen school doors as quickly as possible.”
But with about half of American students still learning virtually as the pandemic nears its first anniversary, the president’s push is far from certain to succeed. His plan is rolling out just as local battles over reopening have, if anything, become more pitched in recent weeks.
Teachers are uncertain about when they will be vaccinated. With alarming case counts across the country and new variants of the coronavirus emerging, unions are fighting efforts to return their members to crowded hallways.
The Chicago Teachers Union told members to defy orders to return to the classroom on Monday and to begin working remotely. The teachers say the district has not done enough to keep students and teachers safe during the pandemic. Students are supposed to come back to classrooms on Feb. 1.
Given the seemingly intractable health and labor challenges, some district officials have begun to say out loud what was previously unthinkable: that schools may not be operating normally for the 2021-22 school year. And some labor leaders are seeking to tamp down the expectations Mr. Biden’s words have raised.
“We don’t know whether a vaccine stops transmissibility,” said Randi Weingarten, president of the American Federation of Teachers, the nation’s second-largest teachers union.
Some virus experts, however, have said there is reason to be optimistic on this question.
Ms. Weingarten said a key to returning teachers to classrooms in the coming months would be promises to allow those with health conditions, or whose family members have compromised immune systems, to continue to work remotely; the collection of centralized data on the number of coronavirus cases in specific schools; and assurances from districts that they would shut down schools when cases occur.
Fights over those very demands have slowed and complicated reopenings across the country.
Mr. Biden’s executive order directs federal agencies to create national school reopening guidelines, to support virus contact tracing in schools and to collect data measuring the impact of the pandemic on students. The White House is also pushing a stimulus package that would provide $130 billion to schools for costs such as virus testing, upgrading ventilation systems and hiring staff members.
Research has pointed to the potential to operate schools safely before teachers and students are vaccinated, as long as practices like mask wearing are adhered to, and especially when community transmission and hospitalization rates are controlled.
An official in the northeastern Chinese city of Tonghua, where residents are barred from leaving their homes amid a strict lockdown, apologized to residents who said they had not been receiving enough food.
Tonghua, an industrial city of about two million people in Jilin Province, went into lockdown on Jan. 20 after the number of recent cases grew to nearly 100. Since then the local outbreak has been largely brought under control, with just two new symptomatic cases reported on Saturday.
As China observes the first anniversary of the lockdown in Wuhan, the central city where the virus was first discovered, other parts of the country are confronting smaller outbreaks. The government has responded with mass testing and citywide lockdowns that at one point affected more than 28 million people, almost three times the size of the population that was initially locked down in Wuhan.
On Monday, China reported 124 new cases in the previous 24 hours, including 117 local cases and seven among travelers in quarantine after returning from overseas. That is an increase from 80 cases reported a day earlier, though still vastly lower than other large countries. Mainland China, which has a population of 1.4 billion people, has recorded a total of about 100,000 coronavirus cases and 4,635 deaths, according to a New York Times database.
In Tonghua, the tough restrictions on movement have led to widespread complaints, with residents taking to social media to vent and seek help. Jiang Haiyan, a deputy mayor, acknowledged the problems on Sunday, saying that a lack of personnel had hindered the distribution of supplies.
“At present, there are problems of untimely and inadequate distribution of household materials for citizens, which has caused great inconvenience to everyone’s lives,” Ms. Jiang said.
The city’s Communist Party committee and local government “express their sincere apologies to everyone,” she added.
The city had since recruited a large number of community workers and volunteers to ensure adequate supply distribution, Ms. Jiang said.
But on the social media accounts for The People’s Daily, the Communist Party’s main newspaper, some people continued to express dissatisfaction with the situation.
“Before the residents weren’t treated humanely, they didn’t tell us anything and in one night went from house to house sealing everything up,” read one popular reply. “Now grass-roots officials and volunteers are treated inhumanely, and in one night all the food must be distributed door to door.”
Livia Albeck-Ripka, Christopher F. Schuetze, and Lin Qiqing contributed reporting.
In other developments around the world:
Australia on Monday approved the Pfizer-BioNTech coronavirus vaccine for use among people 16 and older, the country’s first vaccine approval. Vaccinations are expected to start late next month. The announcement came one year to the day after Australia reported its first coronavirus case.
Officials in New Zealand confirmed on Monday a case of the South African variant of the coronavirus in a returned traveler a week after she left hotel quarantine. Officials have said the 56-year-old, who had tested negative twice before being allowed to return home, was probably infected by a fellow returned traveler while in quarantine. People who were at the same hotel have been urged to self-isolate immediately. It is the first case New Zealand has recorded outside quarantine since November. The government in Australia responded on Monday by suspending its travel bubble with New Zealand for at least 72 hours, saying all travelers from the country must quarantine on arrival.
After delays, Turkey received 6.5 million more doses of a Chinese-produced coronavirus vaccine Monday morning, the state-run news agency, Anadolu, reported. Turkey was expecting to receive at least 10 million doses of the vaccine in December, and 20 million more in January. But the batches were delayed and the number of doses remained below expectations, an apparent blow to China’s vaccine diplomacy. Turkey has given more than 1. 2 million inoculations, according to Health Ministry data available online, using the CoronaVac shot from the Chinese company Sinovac. Almost 2.5 million people in Turkey are infected with the coronavirus and more than 25,000 people have died, government data shows.
A Berlin hospital was forced to lock down and put its entire staff in quarantine, after 20 cases of the new British variant of the coronavirus were found among patients and hospital workers. The hospital, Vivantes Humboldt-Klinikum, in the northwestern neighborhood of Reinickendorf, stopped taking new patients on Friday night and has put its entire staff — as many as 1,700 nurses, doctors, caregivers, support staff and administrators — under quarantine. Those required to come to work who do not have private means of transportation are using specially organized ride-hailing services to avoid coming into contact with the population at large.
Providing reliable internet access to the 111,000 children in homeless shelters and unstable housing in New York City has been one of the most stubborn obstacles to getting online schooling right, and for many students there’s no relief in sight. The city belatedly started putting Wi-Fi in 200 family shelters in November and says it won’t finish until the end of summer, after a second pandemic school year has come and gone.
In November, when a lawsuit demanded that the city speed up and complete the Wi-Fi project by early January, the city protested that it was being asked to “perform the impossible,” listing 14 bureaucratic hurdles to be cleared at each shelter before installation could begin.
But operators who collectively run more than a dozen of the city’s 200 family shelters have proved it is not impossible at all.
Recognizing the urgency of the situation, they took it upon themselves to get their buildings wired months ago and got it done within weeks — most for a fraction of what the city is paying the cable giants Spectrum and Optimum to do the job over nearly a year.
The city is installing cable and a Wi-Fi router in every shelter apartment, while most shelters that did it themselves had contractors install access points in hallways that they say provide fine service.
“Given the fiscal crisis the city finds itself in, this is just silly,” Catherine Trapani, the executive director of Homeless Services United, a coalition of shelter operators, said this month. “There’s a cheaper, faster way — what is the reason you wouldn’t try to do it?”
Robin Levine, a spokeswoman for the city’s Department of Information Technology and Telecommunications, said in a statement that installing a Wi-Fi setup in each apartment was “the only way to ensure families will have a permanent, reliable way to access the internet.”
The city’s solution “accounts for long-term support needs” and is over all “better, stronger and cheaper,” Ms. Levine wrote.
The city declined to say how many students in homeless shelters still lack reliable internet but has said in court filings that a survey starting in late October found nearly 3,000 shelter families with school-age children reported problems with city-issued iPads.
As frustrating and cumbersome as remote schooling has been for students and families all over, the process of getting New York’s poorest students connected has been a case study in complication. When Mayor Bill de Blasio shut down schools on March 15, his Department of Education began distributing internet-equipped iPads with unlimited T-Mobile data plans to every child who needed one. But inside many shelters, T-Mobile’s signal was weak or nonexistent.
When Mount Sinai Hospital opened its Center for Post-Covid Care in May, it was the first such facility in the United States. The doctors there expected to treat patients who had been severely ill or hospitalized. By that point, three months into the pandemic, they knew that the coronavirus could cause harm to many parts of the body beyond the airways where infections most commonly begin. And they knew that medical treatments meant to save patients’ lives could also take a toll. Recovery from having been put on a ventilator, in particular, could be a lengthy process.
Mount Sinai sought to support patients recovering from severe Covid-19 by giving them access to a multidisciplinary medical team that included lung, heart and kidney doctors, rehabilitation specialists and psychiatrists for those whose mental health might have been affected by their ordeals.
Hundreds of patients, most of them women, showed up soon after the center’s doors opened. To the doctors’ surprise, however, many of them had experienced only mild cases of Covid-19. They hadn’t been hospitalized. They were relatively young and otherwise in good health, without the underlying conditions like obesity and diabetes that are known to make Covid-19 worse.
And yet, months after their bodies had seemingly fought off the coronavirus, they still felt quite ill. “We’ve heard of illnesses, viral illnesses, that have a prolonged postviral phase,” said Dr. Zijian Chen, the head of Mount Sinai’s recovery center. “But these usually don’t last for the months and months that we see here. And because of that, we’re a little surprised that this is happening. It tells us how much we don’t know about this illness.” The center has now seen more than 1,600 patients.
These patients have labeled themselves “Covid long-haulers.” As a group, they report a strange hodgepodge of symptoms, including fatigue, pain, shortness of breath, light sensitivity, exercise intolerance, insomnia, hearts that race inexplicably, diarrhea and cramping, memory problems and a debilitating “brain fog” that can at times make it hard to put a cogent sentence together.
Back in the glory days of newsmagazines, the editors at Newsweek used to sit around and fantasize about their dream “doomsday” team — the clutch of journalists they would want on hand if they had to cover the end of the world. One name was always at or near the top: Sharon Begley.
Ms. Begley, a marquee journalist for Newsweek for more than 25 years and widely regarded as one of the pre-eminent science writers of her generation, was fast and trustworthy and could turn a phrase. She died at 64 on Jan. 16 at a hospital in Boston. Her husband, Edward Groth, said the cause was complications of lung cancer.
After Newsweek, Ms. Begley wrote for The Wall Street Journal, Reuters and, for the last five years, Stat, the Boston-based health and science news website, where she was one of its lead writers on Covid-19.
At Stat, she tested then-President Trump’s claim that more Covid-19 tests create more cases; she reported on flaws when checking fevers to flag infected people and recommended smell tests instead; the retractions of two Covid-19 papers from top medical journals and more.
In a 43-year career, she took home a boatload of science-writing prizes.
In the days after her death, tributes on social media came as much from the scientists she had written about as the journalists she had worked with, including a lead coronavirus expert, Dr. Francis S. Collins, the director of the National Institutes of Health.
Dr. Collins wrote on Twitter that Ms. Begley would be “long remembered for making the most complex science stories both exciting and accessible.”