
Around the world, borders were being tightened this week as rising cases and the threat of more contagious virus variants taking hold prompted travel policy changes from the United States to Europe to Australia.
Even as the United States moved to impose travel restrictions, citing the danger of the fast-moving variants, a case of the variant spreading in Brazil was identified in Minnesota.
In Europe, France is moving to impose strict border measures, Britain is considering a mandatory hotel quarantine for some travelers, and the European Union is urging more coordinated action among member states to limit travel.
Prime Minister Jacinda Ardern of New Zealand said on Tuesday that the country’s borders would remain closed until New Zealanders had been “vaccinated and protected.” Australia has suspended its travel bubble with New Zealand for 72 hours from Monday, after New Zealand confirmed a case outside its quarantine system of the variant found in South Africa.
As of Tuesday, the United States will begin requiring a negative virus test from all arriving international air travelers. The Biden administration has announced that it is extending a ban on travel by noncitizens into the United States from Brazil, Britain and 27 other European countries, and adding South Africa to the list.
The Brazil-based variant, known as B.1.1.28.1 or P.1, was identified Monday in a Minnesota resident who had recently traveled to Brazil, the state health authorities said, which could suggest that the variant might not yet be widely circulating.
Dr. Anthony S. Fauci, an adviser to President Biden, said it was only a matter of time before the Brazil-based variant was detected in the United States. “With the world travel that you have, and the degree of transmissibility efficiency, it’s not surprising,” he said.
The variants have arrived just as there are signs of progress. Hospitalizations, after peaking in early January, are at their lowest level nationally since Dec. 13, according to the Covid Tracking Project. The average daily caseload in the United States is down by about one-third compared with two weeks ago, according to a New York Times database.
And after a slow start, the pace of vaccinations is picking up, and the United States already seems to be vaccinating well over a million people per day, according to a New York Times analysis of data from the Centers for Disease Control and Prevention. Mr. Biden said Monday that he is now aiming for the United States to administer 1.5 million doses a day, a 50 percent increase from his initial target.
But scientists fear much of the country’s momentum could be quickly halted if the variants continue to spread unchecked. They are especially anxious about the variants spreading in Brazil and South Africa, which share many mutations, because they may be able to blunt the effectiveness of vaccines.
The United States is flying blind, scientists have warned, as the country navigates the spread of the new variants without a large-scale, nationwide system for checking virus genomes for new mutations. Instead, the work of discovering the variants has fallen to a patchwork of academic, state and commercial laboratories.
Scientists say that a national surveillance program would be able to determine just how widespread the new variant is and help contain emerging hot spots, extending the crucial window of time in which vulnerable people across the country could get vaccinated.

Beginning Tuesday, travelers from any foreign country flying into the United States must present proof of a negative test for the coronavirus. Many other countries have been requiring negative test results for months, but the United States has been less strict in its travel requirements.
While travel globally will be affected, especially in light of the Biden administration’s decision to bar travelers — excluding American citizens — from Brazil, Britain, Ireland, South Africa and 26 countries in Europe that allow travel across open borders, the biggest impact of the testing rule will be for destinations in the Caribbean and Mexico, which have continued to attract American leisure travelers who cannot go to other parts of the world.
“We keep getting curveballs thrown at us in our whole industry,” said Jason Kycek, senior vice president of sales and marketing at Casa de Campo, a golf-and-beach resort in the Dominican Republic that is expanding its existing on-site testing facilities. “The finish line keeps moving, but we are staying on top of things and making sure our guests have what they need and can travel safely.”
Mexico and countries in the Caribbean have remained popular destinations for American travelers even as other destinations closed their borders, in part because of their proximity to the United States, making them relatively easy and affordable to reach. In the fall, several U.S. airlines added flights to the Caribbean islands and to Mexico at a time when routes elsewhere were being cut. In November, nearly 500,000 Americans flew to Mexico alone, according to official figures.
Under the new requirement, travelers will need to get tested no more than three days before their scheduled flight, showing a negative result to their airline before boarding. Those who have already had the virus will need to show documentation of recovery in the form of a recent positive viral test and a letter from a health care provider or a public health official stating they were cleared to travel.
The United States will accept results from rapid antigen tests, while other countries have been asking for what are known as polymerase chain reaction tests, or P.C.R. tests. Antigen tests have been found to be less reliable than P.C.R. tests.
For an industry already decimated by the pandemic, the new testing requirement may cut into any business rebound. Last week, United Airlines told reporters on its fourth-quarter earnings call that Mexican destinations were among the most affected by the new testing requirement.

Israel, which leads the world in vaccinating its population against the coronavirus, has produced some encouraging news: Early results show a significant drop in infection after just one shot of a two-dose vaccine, and better than expected results after both doses.
Public health experts caution that the data, based on the Pfizer-BioNTech vaccine, is preliminary and has not been subjected to clinical trials. Even so, Dr. Anat Ekka Zohar, the vice president of Maccabi Health Services, one of the Israeli health maintenance organizations that released the data, called it “very encouraging.”
In the first early report, Clalit, Israel’s largest health fund, compared 200,000 people aged 60 or over who received a first dose of the vaccine to a matched group of 200,000 who had not been vaccinated yet. It said that 14 to 18 days after their shots, the partly vaccinated patients were 33 percent less likely to be infected.
At about the same time, Maccabi’s research arm said it had found an even larger drop in infections after just one dose: a decrease of about 60 percent, 13 to 21 days after the first shot, in the first 430,000 people to receive it.
Maccabi did not specify an age group or whether it had compared the data with a matched, non-vaccinated cohort.
The Israeli Health Ministry and Maccabi released on Monday new data on people who had received both doses of the vaccine, showing extremely high rates of effectiveness.
The ministry found that of 428,000 Israelis who had received their second doses, only 63, or 0.014 percent, had contracted the virus a week later. Similarly, the Maccabi data showed that more than a week after having received the second dose, only 20 of roughly 128,600 people, about 0.01 percent, had contracted the virus.
In clinical trials, the Pfizer vaccine proved 95 percent effective after two doses in preventing coronavirus infection in people without evidence of previous infection. The Israeli results, if they hold up, suggest the efficacy could be even higher, though rigorous comparisons to unvaccinated people have not yet been published.
Both Clalit and Maccabi warned that their findings were preliminary and said they would soon be followed by more in-depth statistical analysis in peer-reviewed scientific publications.
Israel, where more than 40 percent of the population has already received one dose of the vaccine, has become something of an international test case for vaccination efficacy.

When New York announced new vaccine eligibility guidelines two weeks ago covering millions of additional state residents, one particularly hard-hit group remained unmentioned: the nearly 50,000 people incarcerated in the state’s prisons and jails.
Now, with state supplies dwindling and no clear plan for vaccinating incarcerated people, the virus is roaring back behind bars. At least 5,100 people living and working in New York’s prisons have tested positive and 12 have died in recent weeks, outpacing even the early days of the pandemic.
But how and when to vaccinate incarcerated people as millions around the state wait has raised legal, logistical and ethical questions.
Across the country, the arrival of a vaccine was hailed as a harbinger of the pandemic’s eventual end. But administering the limited supply has proved challenging, and correctional facilities — where more than half a million people have tested positive for the virus since the start of the pandemic — present additional complications.
Officials grappling with the same difficult questions have come to different conclusions, creating a patchwork of policies and timelines, according to an analysis by the Prison Policy Initiative, a research nonprofit devoted to reducing mass incarceration. But at least 27 states directly name inmates in their public plans, and about a dozen place them in the first phases of vaccine distribution, including Massachusetts, where tens of thousands of prisoners are to be vaccinated by the end of February.
Other states plan to vaccinate prison and jail workers before incarcerated people, breaking with guidance from the Centers for Disease Control and Prevention, which recommends vaccinating everyone at correctional facilities simultaneously. Some, like New York, do not address those behind bars at all.
Vaccinating incarcerated people in the early stages of distribution has proved politically fraught. In New York, state senators have questioned whether prioritizing people in prisons makes sense. In Colorado, a draft plan to offer the vaccine inside prisons was met with fierce opposition for, as one district attorney wrote in The Denver Post, prioritizing “the health of incarcerated murderers” ahead of “law-abiding Coloradans 65 and older.”
New York officials said the state was preparing a plan. Public health experts broadly agree that incarcerated people are at particularly high risk for contracting and spreading the virus; at least 8,800 people living or working in New York’s prison system have tested positive since the start of the pandemic.
And because guards, lawyers, workers and people entering and leaving custody move between the facilities and the community at large, the public health implications of outbreaks behind bars extend far beyond the prison walls.Officials said last fall that an outbreak at Greene Correctional Facility near Albany was linked to cases at an assisted-living facility and an elementary school.

In the latest sign of Britain’s struggle to contain the coronavirus, deaths in the country surpassed 100,000 on Tuesday, according to data released by the Office for National Statistics, considered the more accurate measure of the national death toll.
The news comes as the British government is poised to announce more stringent restrictions in the face of fears over a surge in fast-spreading variants of the virus, including a mandatory hotel quarantine for travelers arriving in the country, according to the BBC. A government announcement could come as early as Tuesday, though details of the extent of the program are still unclear.
Nadhim Zahawi, the British vaccine minister, told Sky News that an announcement on the travel issue would come later on Tuesday, but he declined to offer details on the restrictions.
Lockdown measures are in place across the country as a highly contagious variant discovered in England surges, a contrast to the promising hope of a mass vaccination drive that is underway and proceeding at a fast pace.
The new numbers bring the total number of registered deaths to 103,602 across England, Northern Ireland, Scotland and Wales through the week ending Jan. 15. The government also tracks daily deaths of those who had a positive test result — which have not yet reached 100,000 — but the figures from the Office for National Statistics are considered to be more accurate and comprehensive, despite the lagging time frame.
Those figures are part of a weekly report on the number of deaths registered in Britain that mention Covid-19 on a death certificate where the person had tested positive within 28 days of death, a figure that includes deaths outside hospitals. It is many thousands higher than the reported daily death toll issued in the government’s count.

The pandemic set off an extraordinary surge in biking in New York City as people sought to avoid public transit and embrace new ways to exercise.
But now the spike has run headlong into a familiar problem on the city’s congested streets: no parking.
Cyclists have rolled up to apartment buildings, offices, stores and restaurants only to find nowhere to leave their bikes. Many lug them inside, or improvise makeshift parking by locking them to street signs — breaking a city law that is rarely enforced — or trees, gates and fences.
The lack of parking, cyclists and advocates complain, has helped fuel a jump in bike thefts.
Even as New York has created the largest urban bike network in the nation with 1,375 miles of bike lanes and a thriving bike-share program, it has lagged well behind other cities in making bike parking spots widely available, transportation experts and advocates say.
New York has roughly 56,000 bike parking spots on its streets, sidewalks and plazas. Most are part of bike racks, though there are 83 corrals — car parking spots converted to hold bikes — and 20 shelters that shield bikes from snow and rain. (The 56,000 does not include the sharing program Citi Bike, which has 38,000 spaces in about 1,100 docking stations.)
By comparison, London has three times as much bike parking, with more than 150,000 cycling spaces on its streets and at least 20,000 additional spaces at Underground and rail stations. There are also more than 1,500 spaces in curbside cycle hangers, where residents leave their bikes inside a small metal dome.
Some American cities have increased efforts to create more bike parking during the pandemic. Chicago installed nearly 2,000 new spaces last year on racks and in corrals and plans to add 900 more this spring for a total of roughly 34,260.
In New York, cycling had boomed even before the pandemic, with 490,000 daily bike trips in 2017, up from 150,000 in 2000, according to a 2019 city report. Nearly 1.6 million New Yorkers are bike riders, the report said, with almost half getting on a bike at least several times a month.

For nearly a year, the president of Mexico, Andrés Manuel López Obrador, had minimized the pandemic, claiming that religious amulets protected him, refusing to wear a mask and even drinking from the same clay pot as supporters. It was only a matter of time until he got sick himself, some Mexicans said.
With the president now infected, what most aggrieved many Mexicans was not only that he had flouted basic safety precautions, but also that he may go back to playing down the threat that the surging pandemic poses after his own illness.
They noted that with top-notch medical care delivered at his living quarters, the president may well recover. Their loved ones, on the other hand, will struggle to get the most basic care.
A devastated Mexico is struggling to rein in the pandemic. Last Thursday, the authorities announced more than 1,800 coronavirus deaths, breaking the record of single-day deaths set just days earlier.
In Mexico City, hospitals are at 89 percent capacity, according to the most recent health ministry figures, while nationwide, the figure is 60 percent. Across the country, more than half of all hospital beds with ventilators are full.
So far, more than 1.7 million people have contracted the virus in Mexico and more than 150,000 people have died. That is the fourth-highest death toll in the world.
Amid widespread mistrust of hospitals, many infected people choose to stay home — and often die there. The cause of death may not be listed as Covid-19. That, combined with the country’s low levels of testing, means the pandemic’s true toll is most likely far worse than the official one.
On Monday, the day after the president disclosed his infection, Carlos Slim, a telecommunications tycoon who is the richest man in Mexico, was also reported to have contracted the virus. His son said on Twitter that Mr. Slim, who turns 81 this week, had mild symptoms and was doing “very well.”
While Mr. López Obrador also said that his symptoms were mild and that he “remained positive,” doctors warned that the 67-year-old heart attack survivor was in a high-risk category.
And it remains to be seen if his own bout with the virus will change his attitude toward it.
Mr. López Obrador is not the first world leader to fall ill with coronavirus.
Early last year, Prime Minister Boris Johnson of Britain famously persisted in shaking hands with Covid-19 patients and later was admitted to a hospital himself after contracting the illness.
Mr. Johnson emerged sounding chastened, and with a new, intimate awareness of the virus’s danger. He went on to embrace mask wearing and lockdowns and other measures designed to help stem transmission.
But in Mexico, some public health experts fear their leader will go more the way of former President Donald J. Trump, who beat the virus last year and then continued to play down the pandemic and undermine health officials’ recommendations.

There are Covid-19 bubbles — small clusters of friends or family who agree to socialize exclusively with each other during the pandemic — and then there are the kinds of bubbles the Flaming Lips used at recent concerts.
Band members and concertgoers alike rocked out and bounced while encased in large individual plastic bubbles amid bright swirling lights in trippy scenes at concerts on Friday and Saturday in Oklahoma City.
The band has taken the elaborate precautions at its live performances to protect against the transmission of the coronavirus, but some health experts were unsure about the effectiveness of those measures.
“I’d need to see how the air exchange was occurring between the outside and the inside of the bubbles to be able to say if it were safe over all or reduced risk of transmission,” said Dr. Eric Cioe-Peña, the director of global health at Northwell Health in New Hyde Park, N.Y.
The Flaming Lips, an indie rock band founded in the early 1980s, who are known for their exuberant live shows and recording experiments, performed a similar concert in October. They also performed their song “Race for the Prize” in June using the spheres on “The Late Show With Stephen Colbert.”
The concerts on Friday and Saturday were originally scheduled for December, but the band postponed them because of rising Covid-19 cases in the Oklahoma City metro area.
“It’s a very restricted, weird event,” the band’s frontman, Wayne Coyne, told Rolling Stone last month. “But the weirdness is so we can enjoy a concert before putting our families and everybody at risk.”
Global Roundup

Indonesia officially passed one million coronavirus cases on Tuesday, with many hospitals near capacity even as vaccinations are underway. As in many countries, however, the true number of infections is likely to be much higher.
Indonesia, which has the world’s fourth-largest population at more than 270 million, never succeeded in containing its first wave of infections, and the daily numbers of new cases and deaths have surged to their highest levels in the past 10 days.
On Tuesday, officials reported 13,094 new cases and 336 deaths for a total of 1,012,350 cases, the highest in Southeast Asia. Indonesia is the 19th country to surpass one million cases, and among Asian nations it trails only India in the number of cases.
Dicky Budiman, an epidemiologist who studies pandemics and global health security at Griffith University in Australia, has been saying for months that Indonesia is undercounting its case numbers by a third or more.
He estimates that the country has at least 60,000 new infections each day, more than four times what the government is reporting.
“The response they give to the pandemic is not equal to the problem,” said Dr. Dicky, a former Indonesian health official.
Though Indonesia began its vaccination program almost two weeks ago, it is likely to be some time before there is a significant effect on new infections. A government spokesman said that as of Tuesday, 162,000 people had received the first of two doses of the vaccine made by Sinovac, a private Chinese company. With a population spread across thousands of islands, experts say vaccinating enough Indonesians to reach herd immunity could take a year or more.
Here’s what else is happening around the world:
-
Violent protests erupted for the third night in cities across the Netherlands, with stores looted and rocks and fireworks thrown at police officers in response to a national 9 p.m. curfew that went into effect on Saturday. In total, the police arrested more than 150 people nationwide, the police chief told the Dutch broadcaster NOS.
Politicians echoed a similar sentiment. “What’s happening in the Dutch streets is unprecedented,” Wopke Hoekstra, the finance minister, told Dutch television on Tuesday. Ferd Grapperhaus, the justice minister, called the violence “outrageous” and indicated that the protests were no reason to rethink the strict lockdown measures. “We need the curfew,” Mr. Grapperhaus said.
-
France announced on Tuesday that it would not delay the second dose of the Pfizer-BioNTech vaccine to quickly maximize the number of people receiving a first shot, as some countries have done. The French health minister, Olivier Véran, said at a news conference that the debate on delaying the second dose was “legitimate” but that it was still unclear how efficient the vaccine would be if administered six weeks after the first shot, instead of the recommended three to four weeks. “I am choosing the security of confirmed data,” Mr. Véran said.
-
A World Health Organization panel of experts recommended on Tuesday that the Moderna Covid-19 vaccine be given in two doses spaced 28 days apart, which could be extended under exceptional circumstances to 42 days. The guidance was issued by the organization’s Strategic Advisory Group of Experts on Immunization several weeks after it issued similar guidance on the rival Pfizer shot, according to Reuters.

The European Union escalated a war of words with AstraZeneca on Monday over the company’s sudden announcement on Friday that it would have to drastically cut the number of vaccine doses delivered to the bloc and its 27 members.
The European health commissioner, Stella Kyriakides, said a call with the company’s leadership on Monday had not yielded sufficient answers as to why the company was breaking its contractual obligation and said another call would be held on Monday evening.
A spokesperson for AstraZeneca, said: “Our C.E.O. Pascal Soriot was pleased to speak with the Commission President Ursula von der Leyen earlier today. He stressed the importance of working in partnership and how AstraZeneca is doing everything it can to bring its vaccine to millions of Europeans as soon as possible.”
The AstraZeneca debacle delivers a serious blow to the bloc’s sluggish vaccination rollout, and comes days after Pfizer notified E.U. members and several other countries that it would slow down deliveries until mid-February as it upgraded its Belgium factory to increase production.
The twin disappointments have left several E.U. countries hamstrung, and have thwarted the bloc’s collective effort to vaccinate 70 percent of its population by this summer, as Britain and the United States are making better progress with their inoculation programs.
“The European Union has pre-financed the development of the vaccine and its production, and wants to see the return,” Ms. Kyriakides said, implying that the E.U. was concerned the company had sold the vaccines the bloc had funded to other countries.
“The European Union wants to know exactly which doses have been produced, where by AstraZeneca so far, and if, or to whom, they have been delivered,” she added.
Ms. Kyriakides also said that the European Commission, the executive branch of the E.U., was proposing its members approve a system in which pharmaceutical companies like AstraZeneca that produce vaccines in plants in E.U. territory would need to register any intention to export part of that production outside the bloc.

Germany’s Health Ministry has denied widely criticized and thinly sourced reports in local news outlets that AstraZeneca’s coronavirus vaccine is barely effective in protecting older people, stressing that the data was still being reviewed as European Union regulators consider approving the vaccine.
“The German Ministry of Health cannot confirm recent reports of reduced efficacy of the AstraZeneca vaccine,” the ministry said in a statement on Tuesday, after two leading German newspapers reported that the vaccine had proved effective in just 8 percent of people over 65.
“At first glance, it appears that two things have been confused in the reports: About 8 percent of the subjects in the AstraZeneca efficacy trial were between 56 and 69 years of age, and only 3 to 4 percent were over 70 years of age,” the ministry said. “However, this does not imply an efficacy of only 8 percent in seniors.”
The German health minister, Jens Spahn, called the reports “speculation” early Tuesday and pointed out that the available data had not yet been fully assessed.
“It has long been clear — there was a discussion in the fall — that there is less data for older people,” Mr. Spahn said.
AstraZeneca refuted the initial reports in the German media on the effectiveness of the vaccine, calling them “completely incorrect.” AstraZeneca and Oxford, which developed the vaccine, have not released figures on how effective the vaccine is for different age groups.
The AstraZeneca vaccine has been approved for emergency use in several countries, including Britain, India and Mexico, but not yet in the European Union. The company applied for authorization on Jan. 12, and the European Medicines Agency, the bloc’s drug regulator, is expected to announce its decision on Friday.
The reports come amid growing concern in Germany over the sluggish start to the country’s mass vaccination program, after AstraZeneca informed Brussels on Friday that it would not be able to deliver the anticipated number of doses to the European Union, because of slow production at a manufacturing site within the bloc.
Chancellor Angela Merkel and Mr. Spahn have pledged to make vaccines available by Sept. 21 to all adults in Germany who want the shot. That promise is dependent on the country receiving the 56.2 million does of the AstraZeneca vaccine, based on its original delivery pledge.