Austria is ending its Covid rules for unvaccinated people. England is leaving behind its “war footing” in its approach to the coronavirus. And the Netherlands, which introduced some of Europe’s strictest Covid measures in December, is relaxing restrictions.

But farther east, record coronavirus caseloads are prompting governments to ramp up rules and testing.

As the highly infectious Omicron variant storms its way eastward across Europe, two divergent trends have emerged: Some governments have been moving to ease restrictions despite rising cases or as new daily cases or hospitalizations fall, while others have been clamping down to curb a spike in cases.

In Austria, Wolfgang Mückstein, the health minister, said on Wednesday that Covid rules for unvaccinated people would end next week, based on guidance from health advisers that hospitals and intensive care units in the country are becoming less burdened even as virus cases rise.

“We came to the conclusion that the lockdown for unvaccinated people in Austria is only justifiable in the event of the threat of an imminent overburdening of intensive-care capacity,” Mr. Mückstein said at a news conference.

In the Netherlands, where stringent lockdowns have put a strain on the population, the Dutch government said that it was “taking a risk” in easing restrictions starting Wednesday despite a growing caseload. Businesses like cafes, bars and restaurants will be allowed to stay open until 10 p.m., although people will be required to show proof of vaccination or a negative test result before entering.

Similar announcements have come this past week from Denmark and France, where restrictions will ease starting next month.

In England, where there has been a decline in cases, most of the remaining pandemic restrictions are being lifted this week. And starting on Feb. 11, people arriving in the country will no longer be required to take coronavirus tests before traveling, as long as they are fully vaccinated.

But in other parts of Europe, governments have scrambled to bring in new rules.

In Germany, which has recorded an average of more than 123,000 cases per day in the last week, lawmakers are discussing a proposal for a Covid vaccine mandate in Parliament.

Poland has stepped up testing and switched to remote learning until the end of February for some older students to curb the spread of the virus, while Eastern European countries like Bulgaria, Hungary and Romania are reporting daily cases records that are projected to keep rising in the coming days.

But in Russia, which has had more known fatalities from Covid than many European countries and where cases have been steadily rising in recent weeks, the authorities have moved to shorten the isolation period for people infected with the virus to seven days, down from 14.

Moderna has begun a study of a booster shot designed specifically to fend off the Omicron variant of the coronavirus, the company said on Wednesday, one day after Pfizer and BioNTech said that they had launched a study of their own Omicron-specific shot.

Moderna also announced the results of a small laboratory study suggesting that the protection its authorized booster shot provides against Omicron infections is likely to fade over the course of six months.

After a single dose of the current booster, the level of Omicron-fighting antibodies rose 20 times higher than their peak before the shot, the company said. After six months, however, these antibody levels had fallen more than sixfold, though they still remained detectable in all of the booster recipients studied.

Antibodies against the original version of the virus fell roughly twofold over the same time period, the company said. The results were published in The New England Journal of Medicine on Wednesday.

Stéphane Bancel, Moderna’s chief executive, said in a statement that the company was “reassured” by the persistence of Omicron-neutralizing antibodies six months after the booster shot. “Nonetheless, given the long-term threat demonstrated by Omicron’s immune escape, we are advancing our Omicron-specific variant vaccine booster candidate,” he said.

Although Omicron can evade the antibodies elicited by the authorized vaccines, making breakthrough infections more common, the vaccines still provide strong protection against hospitalization and death.

Moderna’s new study will examine the safety of, and immune responses to, a single Omicron-specific booster dose in about 600 adults. The company will assess the shot’s performance in two groups of volunteers: some who have received two doses of Moderna’s current vaccine and others who have received two doses plus a booster.

The company did not say when it expected to have results.

Pfizer, which plans to enroll as many as 1,420 people in its study, said it expected to have results in the first half of this year.

The U.S. Navy has kicked out 45 sailors for refusing to be vaccinated against the coronavirus — the first dismissals of Navy personnel since the deadline for active-duty sailors to be inoculated passed on Nov. 28.

All of the sailors were given either honorable or entry-level discharges for disobeying a lawful order obligating them to be vaccinated. Nearly half were within their first six months of service.

The Navy announced the news in a message sent to reporters on Wednesday, noting that 5,035 active-duty sailors and 2,960 reservists remained unvaccinated.

All military service members were required to be vaccinated for Covid-19 under a policy issued by Secretary of Defense Lloyd J. Austin III on Aug. 24. Since then, about 97 percent of active-duty members have had at least one shot; nearly 92 percent of the 2.1 million people who make up the total force are now fully vaccinated.

Last month, the U.S. Air Force dismissed 27 service members for refusing to be vaccinated. Each service branch has a different deadline for shots, and the Air Force was the first to hit the deadline. The 27 — all with less than six years of service — were the first believed to have been fired, Pentagon officials said.

The Navy said that more than 3,200 active-duty sailors had requested exemptions from the vaccination requirement on religious grounds, though none of those requests have been granted.

A group of 35 sailors, 26 of whom are members of the SEALs, sued President Biden in a federal court in Texas on Nov. 9, claiming that the Pentagon’s vaccine requirement infringed on their religious liberties. On Jan. 3, Judge Reed O’Connor of the Northern District of Texas granted a preliminary injunction in the case, temporarily preventing the Defense Department from taking disciplinary action against those sailors.

According to Navy records, more than 128,000 Navy Department personnel, including service members and their family members as well as civilian employees and contractors, have contracted the coronavirus, leading to 187 deaths. Of those, 17 were active-duty or reserve sailors.

Brazil is facing a measles outbreak. In Haiti and the Dominican Republic, diphtheria infections are putting the growth and development of children at risk.

Across Latin America and the Caribbean, countries are contending with outbreaks of diseases like those that used to be under control, because millions of children have fallen behind on routine vaccinations during the coronavirus pandemic, World Health Organization officials said on Wednesday.

“Vaccination coverage has dipped so low that countries are at risk of losing two decades of immunization progress,” Dr. Carissa F. Etienne, the director of the Pan American Health Organization, a division of the W.H.O., said at a news conference.

“Countries must see routine immunizations for what they are: essential,” Dr. Etienne added. “These services were critical before the pandemic, and they remain central to our Covid responses so our children don’t fall further at risk.”

The warnings about faltering vaccinations of children come at a time when children are making up a rising share of people sick with Covid-19, she said.

“Because of the scale of the ongoing outbreaks, more people of all ages are becoming infected with the SARS-CoV-2 virus,” Dr. Etienne said. “And because vaccinated adults are well protected against severe disease, most hospitalizations occur among unvaccinated persons — including children.”

Even so, she said, countries should make sure older residents and those in other at-risk groups are fully vaccinated before concentrating on inoculating children. A high vaccination rate among children should not be a requirement for getting students back into the classroom, she said.

“The first and most important thing countries can try to do for kids is to get them safely back to school, to protect their social, mental and physical well-being,” she said.

New coronavirus cases are soaring in the Americas. The highly contagious Omicron variant, the dominant form of the virus in the hemisphere, is spreading particularly quickly in Mexico’s southern states and in nations like Belize, Brazil, Costa Rica, Ecuador, Honduras, Paraguay and Peru, the organization said.

— Daniel Politi

A coronavirus wave driven by the highly infectious Omicron variant wave may be cresting in parts of North America and Europe, but new cases are still climbing in less-vaccinated regions, and World Health Organization leaders warn that the global surge and the world’s wide vaccine gap could set the stage for another dangerous variant.

Maria Van Kerkhove, the agency’s Covid-19 technical lead, said in a livestream hosted on Tuesday that challenges existed in every country about reaching the most vulnerable unvaccinated communities.

“The fact remains that more than three billion people haven’t received their first dose yet, so we have a long way to go,” said Dr. Van Kerkhove, noting that about 21 million cases were reported to the agency last week. “There are many countries still in the middle of this Omicron wave.”

New daily cases remain at record highs globally, averaging about 3.3 million — an increase of more than 25 percent over two weeks and a staggering rise compared with a rate of about 600,000 a day in early December, according to according to the Center for Systems Science and Engineering at Johns Hopkins University. Cases have continued to rise in Latin America, the Middle East and Asia.

And Omicron is still spreading in Eastern and Central Europe, where vaccination rates are lagging.

Although vaccine shortages are easing, only about 62 percent of the world’s population has received at least one shot, and a striking divide between the rich and poor regions of the world remains. In low-income countries, only 10 percent of the population has received at least one dose. In high- and upper-middle-income countries, 78 percent have received at least one dose.

The potential consequences of the vaccine gap have been underscored by Omicron, which was first identified in southern Africa. Low vaccination coverage creates conditions for widespread virus circulation and with that the possibility of new variants emerging.

Tedros Adhanom Ghebreyesus, the head of the W.H.O., said on Monday that the emergency phase of the pandemic was still very much here.

“It’s dangerous to assume that Omicron will be the last variant or that we are in the endgame,” Dr. Tedros said at an executive board meeting of the organization. “On the contrary, globally, the conditions are ideal for more variants to emerge.”

Dr. Hans Kluge, the director for the agency’s European region, said in a statement on Monday that it was too early for nations to drop their guard, with so many people unvaccinated around the world. But, he said, with more vaccination and natural immunity through infection, “Omicron offers plausible hope for stabilization and normalization.”

During Tuesday’s livestream, W.H.O. officials again emphasized that the virus would continue to circulate and that Omicron would not be the last variant. The next one would need to be even more contagious to overtake Omicron, Dr. Van Kerkhove said, adding that the “big question” was whether it would be more severe.

The agency said that without more equitable distribution and administration of vaccines, the pandemic would be prolonged.

Dr. Mike Ryan, the executive director of its Health Emergencies Program, said that the greatest failure with world’s pandemic response has been “our inability to deliver these lifesaving tools to the people who will benefit most.”

“We can have all the technology and innovation,” he said, “but if we don’t have the mechanisms for how the fruit of that innovation are going to be shared, then we fail.”

Boys aged 12 to 15 have a small but increased risk of heart problems after receiving a second dose of the Pfizer-BioNTech vaccine, Israeli researchers reported on Wednesday.

Myocarditis, or inflammation of the heart muscle, occurred in one of 12,361 boys of that age group within a week of receiving a second dose, the study found.

The cases were mild, and the side effect remains uncommon. Moreover, several studies have shown that the risk of myocarditis after Covid is much higher than that after vaccination.

Still, the Israeli figure is higher than the Centers for Disease Control and Prevention estimate of one case per 16,129 vaccinated adolescents aged 12 to 17. Israeli researchers previously reported that nearly 11 of every 100,000 boys and men aged 16 to 29 were at heightened risk of myocarditis after vaccination.

Although the new results are based only on the Pfizer-BioNTech vaccine, other studies have found that the incidence of myocarditis may be higher with the mRNA vaccine made by Moderna. Myocarditis can manifest as chest pain, shortness of breath and the feeling of having a fast-beating, fluttering or pounding heart, according to the C.D.C.

Some European countries paused the use of the Moderna vaccine in male adolescents because of the risk. In the United States, only the Pfizer-BioNTech vaccine is authorized for use in adolescents and children 5 and older.

Concern about heart inflammation may have prompted the Food and Drug Administration to ask Pfizer-BioNTech and Moderna to enroll more children in their vaccine trials. Even so, Pfizer’s trial of the vaccine included just 567 boys aged 12 to 15 — too few to detect uncommon side effects.

The new study tracked hospitalizations for myocarditis from June 2 to Oct. 20, 2021, through a surveillance system of Israel’s Health Ministry. During that time, 404,407 adolescents ages 12 to 15 received a vaccine dose, and 326,463 adolescents received a second dose.

The researchers found 18 reports of hospitalization for myocarditis. They excluded two of the cases because of “reasonable alternative diagnoses” and two others because they occurred 46 and 70 days after the second dose — too long after the vaccination to be related, the researchers said.

Of the remaining 14, one was in an unvaccinated adolescent, one in an adolescent who had received the first vaccine dose within 21 days, and 12 cases within a week after the second dose. The results were published in The New England Journal of Medicine.

All of the cases were clinically mild, and the adolescents were hospitalized for an average of three days. None were readmitted during 30 days of follow-up.

The researchers estimated that myocarditis occurs in 0.56 male adolescents per 100,000 after a first dose, and in 8.09 per 100,000 after a second dose. The corresponding risk among girls of that age was negligible.

The study may have underestimated the risk of myocarditis, because the researchers looked only at boys who were hospitalized for the condition.

New York City’s public schools will halve the minimum required isolation period for students who test positive for the coronavirus, and the quarantine rule for unvaccinated students who are exposed to the virus, to five days from 10, officials at the Department of Education said.

The new policy, effective Jan. 31, will require all students in kindergarten or higher grades who test positive to stay home for at least five days. Unvaccinated students exposed to the virus outside of school will have to do the same.

Students can return on Day 6 as long as they have not had a fever for at least 24 hours and are wearing a “well-fitting” mask, though all students and staff members are still required to wear a mask at all times.

The policy changes, which were first reported by NY1 on Tuesday, are in line with guidance from the Centers for Disease Control and Prevention, according to Nathaniel Styer, a spokesman for the education department. They also bring the city in line with state guidance for schools issued on Jan. 14.

Preschool students who are at least 2 years old and test positive for the virus will still be required to isolate for 10 days, but those who are exposed but have not tested positive themselves will now be allowed to return after five, provided they have no symptoms and receive a negative result on a P.C.R. test taken on their fifth day of quarantine, or two negative at-home rapid tests taken on Days 4 and 5.

Children younger than 2 will be allowed to return after seven days, as long as they have no symptoms and have received a negative result from a P.C.R. test taken on Day 5 or later.

The recent surge in cases from the Omicron variant has begun to decline in the city, though test positivity rates remain very high and hospitals are still struggling to keep up with hospitalizations. As of Tuesday, an average of about 10,375 people are testing positive for the coronavirus in New York City each day, according to a New York Times database.

The rapidly changing Covid-19 situation continues to disrupt the city’s classrooms, with 1,445 students and 307 staff members testing positive for the virus on Tuesday, according to data provided by the education department.

Neil Young wasn’t bluffing.

Spotify said on Wednesday that it had begun removing the singer and songwriter’s music from the streaming service, two days after he briefly posted a public letter calling on Spotify to choose between him and Joe Rogan, the star podcast host who has been accused of spreading misinformation about the coronavirus and vaccines.

Young’s challenge to Spotify has become a high-profile, if unexpected, flash point in the battle over misinformation and free speech online. It also raised questions about the power of performing artists to control where their work is heard.

In a statement posted to his website on Wednesday, Young called Spotify “the home of life threatening Covid misinformation.” He added: “Lies being sold for money.”

His criticism of Rogan — a comedian and actor who has become Spotify’s most popular podcast host, sometimes speaking at great length with controversial figures — came after a group of hundreds of scientists, professors and public health experts asked Spotify to take down an episode of Rogan’s show from Dec. 31. That episode, featuring Dr. Robert Malone, an infectious-disease expert, promoted “several falsehoods about Covid-19 vaccines,” according to the group’s public letter, which was issued on Jan. 10.

Spotify said in a statement on Wednesday: “We want all the world’s music and audio content to be available to Spotify users. With that comes great responsibility in balancing both safety for listeners and freedom for creators. We have detailed content policies in place and we’ve removed over 20,000 podcast episodes related to Covid since the start of the pandemic.”

“We regret Neil’s decision to remove his music from Spotify,” the service added, “but hope to welcome him back soon.”

Young’s most popular songs, like “Heart of Gold,” “Harvest Moon” and “Old Man,” have been radio staples for decades, and have attracted hundreds of millions of streams on Spotify. In his statement on Wednesday, Young said that Spotify represented 60 percent of the streams of his music around the world.

Young’s music was expected to be fully removed from Spotify within hours. The news that the service was removing his songs was earlier reported by The Wall Street Journal.

In his original letter, which Young addressed to his label, Warner Records, and his manager, he said: “Spotify has a responsibility to mitigate the spread of misinformation on its platform. I want you to let Spotify know immediately TODAY that I want all my music off their platform.”

He added: “They can have Rogan or Young. Not both.”

That letter was removed from Young’s website soon after it was posted, though it drew wide news media attention.

Rogan, a comedian and actor, signed an exclusive podcast deal with Spotify in 2020 that has been reported to be worth $100 million, though Spotify has not confirmed that figure. His show is the most popular on Spotify.

Spotify has defended Rogan in the past, including after an episode that featured the conspiracy theorist Alex Jones in 2020. “We want creators to create,” Daniel Ek, the chief executive and co-founder of Spotify, told The Financial Times then. “It’s what they do best. We’re not looking to play a role in what they should say.”

Spotify has 318 million monthly listeners around the world, including 172 million who pay for subscriptions, according to the company’s most recent financial disclosures.

In the past, Young has removed his music from streaming services, only to quietly reinstate it. In 2015, after making complaints about the quality of sound on streaming, he took his music down from all major audio streaming services, including Spotify and its biggest rival, Apple Music. But it was added back soon after.

Although virtually all of Young’s music had been removed from Spotify by Thursday — a handful of live recordings and other miscellaneous tracks remained — it is widely available for streaming elsewhere, including on Apple Music, Amazon and YouTube.

Young also operates a subscription service through his own website, Neil Young Archives, offering access to his entire catalog for $20 a year. On Thursday, SiriusXM announced that it was bringing back “Neil Young Radio,” a curated station that it had introduced last month. It will run as a satellite station for a week, and for a month on the company’s SXM app.

Jenny Gross contributed reporting.

As South Korea experiences a surge in the Omicron variant and another record increase in coronavirus daily cases, health officials on Wednesday pivoted to a new testing strategy to target high-risk groups for early detection and treatment.

Rapid antigen tests will be administered only to low-risk groups, while polymerase chain reaction, or P.C.R., tests will continue to be given to high-risk groups, including those over age 60 and people with underlying health problems. Until now, P.C.R. tests had been available to both groups.

The new testing protocol will be effective on Wednesday in four major Omicron hot spots and will expand to the rest of the country over the weekend. It follows moves by other countries, including France, Singapore and Israel, to rely on rapid tests to tackle outbreaks. This month, the Biden administration made it possible for U.S. residents to order up to four free rapid tests online for home delivery, after announcing in December that the government had purchased 500 million such tests.

While P.C.R. tests must be processed by a lab and results can take more than 24 hours to deliver, rapid antigen tests can be taken at home, and testers can get results within minutes. Some have questioned the accuracy of the rapid tests, which are less sensitive than P.C.R. tests, but experts say both are highly reliable.

South Korea’s shift in strategy comes as the country recorded its highest number of daily cases on Wednesday, 13,012, up from 8,571 on Tuesday. The health authorities predict that the nation could see 20,000 to 30,000 cases a day by the end of February and up to 100,000 later in the year.

While those numbers are relatively small compared with cases in other nations like the United States, Korean officials are seeking ways to grapple with steadily rising numbers driven by the Omicron variant.

The new variant was detected in half of the country’s confirmed cases as of Monday, and that figure is expected “to reach 80 to 90 percent or more in the next two to three weeks,” Son Young-rae of the Central Disaster and Safety Countermeasures Headquarters said at a news briefing on Tuesday.

South Korea has fully vaccinated 85 percent of its population.

An Australian naval ship carrying aid supplies arrived in Tonga on Wednesday, a day after the Australian defense minister said that 23 people aboard the vessel had tested positive for the coronavirus.

The ship, the H.M.A.S. Adelaide, docked in Tonga early Wednesday evening, Sione Hufanga, the United Nations spokesman in the remote Pacific nation, said in a telephone interview.

“It’s in front of me now,” he said. No one was entering the vessel, he added, and its cargo was being offloaded by machines.

Two weeks ago, Tonga was slammed by the world’s largest volcanic eruption in decades, and a tsunami that followed. The country was smothered with ash and swamped with water, complicating efforts to deliver aid, particularly in remote islands.

At least three people were killed, and the scale of the disaster is still coming into focus, in part because the eruption cut off the nation’s lone connection to the internet. The outbreak on the Australian ship is stoking concerns that aid workers could inadvertently take the virus to Tonga, which reported its first case in October.

Japan’s national broadcaster reported on Wednesday that the country’s Defense Ministry had suspended its aid mission to Tonga because several members of the Japanese Air Self-Defense Force — which has been delivering aid to Tonga since Saturday from a base in Australia — had tested positive for the virus.

Tonga requires arriving travelers to quarantine for 21 days, and about 60 percent of the country’s population has received two doses of a Covid-19 vaccine.

The Australian ministers for foreign affairs, defense and international development said in a joint statement on Wednesday that the H.M.A.S. Adelaide had arrived in Tonga carrying helicopters, engineering equipment and medical and humanitarian supplies. They said it was “undertaking an entirely contactless delivery of humanitarian assistance and disaster relief supplies.”

Peter Dutton, Australia’s defense minister, had said at a news conference on Tuesday that the 23 people aboard the ship who had tested positive for the virus were in isolation.

“Under no circumstance will we compromise the health and well-being of those Tongans, who have already had a concerted effort against the virus,” he said.

Tonga has a population of about 100,000 people. Its geographical isolation — the country’s main island is 1,100 miles northeast of New Zealand — has largely helped it ward off a coronavirus outbreak.

The country’s lone Covid case of the pandemic came from a person who arrived in October on a commercial flight from Christchurch, New Zealand.

It is one of many mysteries about long Covid: Are some people more likely to experience physical, neurological or cognitive symptoms than can emerge, or linger, for months after their coronavirus infections have cleared?

Now, a team of researchers who followed more than 200 patients for two to three months after their Covid diagnoses are reporting that they have identified biological factors that might help predict whether a person will develop long Covid.

The study, published on Tuesday by the journal Cell, found four factors that could be identified early in a person’s coronavirus infection that appeared to correlate with increased risk of having lasting symptoms weeks later.

The factors researchers identified included the level of coronavirus RNA in the blood early in the infection; the presence of certain antibodies that mistakenly attack tissues in the body; the reactivation of Epstein-Barr virus; and Type 2 diabetes.

“This research stresses the importance of doing measurements early in the disease course to figure out how to treat patients, even if we don’t really know how we’re going to use all that information yet,” said Jim Heath, the principal investigator of the study and president of the Institute for Systems Biology, a nonprofit biomedical research organization in Seattle.

It appears that the United States may be at a turning point in the pandemic. The contagiousness of the Omicron variant has many people resigned to the likelihood of being infected, the variant is typically milder than its predecessors, and there is universal vaccine access for people old enough to receive a shot.

The New York Times therefore commissioned a poll of 4,400 people in the country to ask how they are thinking about the pandemic and to gauge how, and when, society might pivot to living with the virus.

A new episode of “The Daily” podcast explores the results of this poll — and the divides in opinion by age, vaccination status and politics.

Democratic state senators questioning Florida’s surgeon general, Dr. Joseph A. Ladapo, about his views on the coronavirus pandemic walked out of a confirmation hearing on Wednesday out of frustration with his responses.

“We don’t feel that we’re getting any answers,” said Senator Lauren Book, the minority leader, before she and the other three Democrats on the Senate Health Policy Committee stood up and left the hearing room.

Committee members had questioned Dr. Ladapo for about an hour regarding the skepticism he had expressed concerning vaccines and masks to slow the spread of the coronavirus. Several times, Ms. Book tried to make Dr. Ladapo answer yes or no to whether vaccines and masks have been effective. But Dr. Ladapo gave longer answers instead, laying out views that were far from the strong endorsements of vaccines, booster shots and mask wearing from the Centers for Disease Control and Prevention.

Dr. Ladapo acknowledged in the hearing that the Pfizer and Moderna vaccines had been shown to have “relatively high effectiveness” in preventing hospitalization and death. But over time, he maintained, they had shown “relatively low protection from infection,” citing breakthrough infections with the Omicron variant.

“Community masking,” Dr. Ladapo added, “is unlikely to have had a substantial impact on the pandemic.” That assertion was at odds with the C.D.C., which has said that mask studies have generally shown mask wearing to reduce coronavirus infections.

Gov. Ron DeSantis, a Republican, appointed Dr. Ladapo in September to the post, which oversees the Florida Department of Health. With Republicans holding a comfortable majority in the State Senate, it is seen as highly unlikely that Dr. Ladapo would be denied confirmation.

Dr. Ladapo, who shares Mr. DeSantis’s opposition to vaccine mandates, mask mandates, school closures and other pandemic restrictions, has kept a busy public profile since his appointment. He removed quarantine requirements for coronavirus exposure in public schools and has discouraged asymptomatic people from being tested for the virus if they are not at high risk of developing Covid-19 complications.

He has declined to disclose his vaccination status.

After Democrats walked out of the confirmation hearing, the Republicans on the committee did not conduct any debate on Dr. Ladapo’s appointment. They voted 6-0 to recommend his confirmation to the full Senate.

More than a year ago, when Covid-19 vaccines became available in the United States and jabs started going into arms, it became a point of pride for some people to show off a bandaged shoulder and a white Covid-19 Vaccination Record card.

But as the pandemic rolled on, and the bandages came off, some people lost track of those awkward 4.25-by-3.5-inch cards.

What if it is lost?

Relax. Many health departments can provide you with your vaccination information. The records themselves aren’t lost.

But if you’re hoping to use that card to prove your vaccination status at work or, say, to travel to a country with a more digital-first approach to record keeping, losing it may make it harder for you.

Here’s what to do.

Your vaccination records might be on your phone.

You could be lucky enough to live in one of the states that let people access their vaccination records from their smartphones. Those states include Arizona, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Indiana, Louisiana, Maryland, Massachusetts, Mississippi, New Jersey, New York, North Dakota, Rhode Island, Utah and Washington.

Other states have websites where vaccination information can be requested, usually as a PDF or email. Those states include Michigan, Minnesota, New Mexico, North Carolina, Oklahoma and Wisconsin.

Things get a little more complicated if you’re in one of the states that didn’t go digital, unfortunately. But you should be able to get your vaccination records by requesting them from your state or county health department.

Could your doctor give you another card?

Your doctor might have extra C.D.C.-issued white cards, and they should at least have a record of when and where you received your vaccine shot(s) and booster(s).

And most states require health care providers who administer vaccine shots to log that information with state health officials. So state health officials should have that information, too.

No, the C.D.C. will not send you another one.

It wasn’t actually the Centers for Disease Control and Prevention that gave you that card bearing its logo. The agency provides them to state health departments, which in turn give them to local vaccination providers.

So, don’t call your friend’s cousin who works at the C.D.C. looking for a favor.

If you were vaccinated at CVS, Walmart or Walgreens, you’re in luck.

These giant chains can provide you records.

• CVS: A record of the vaccination is available to patients via the CVS Pharmacy app or on the company’s website, a spokesman said. A pharmacy employee can print a paper record for you, the spokesman said.

• Walgreens: The company keeps records of all vaccinations administered by its pharmacies, according to a spokeswoman. If patients lose their physical card, they are encouraged to contact their pharmacy for a new one, the spokeswoman said.

• Walmart: If you were vaccinated at a store or one of its sponsored events, Walmart can verify your information and connect with your state’s immunization registry. Once that is complete, Walmart will reissue a vaccine card to reflect the doses administered at Walmart, a spokeswoman said in a statement. The company can also provide that information digitally or via a QR code.

Around the United States, Democratic elected officials who in the pandemic’s early phase shut down cities and states more aggressively than most Republicans did — and saw their popularity soar — are using a different playbook now.

Despite the deadly wave fueled by the Omicron variant, Democratic officials are largely skipping mask mandates and are pushing to keep schools open, sometimes in opposition to health care workers and their traditional allies in teachers’ unions.

The shift reflects a potential change in the nature of the threat now that millions of Americans are vaccinated and Omicron appears to be causing less serious disease. But it is also a political pivot. Democrats are keenly aware that Americans — including even some of the party’s loyal liberal voters — have changed their attitudes about the coronavirus and that it could be perilous to let Republicans brand the Democrats the party of lockdowns and mandates.

Now that vaccines have been proven effective, Americans have lower tolerance for restrictions, strategists and elected officials said. While schools are largely open in the United States, many families are still dealing with the fallout of two years of classroom disruptions.

A survey conducted this month by USA Today and Suffolk University found that while majorities of Democratic voters supported policies like vaccination mandates and masking, only 43 percent backed shifting schools to remote learning.

Unvaccinated health care workers in roughly half the United States are required to get a first dose of a Covid vaccine by Thursday under a federal mandate that has understaffed hospitals and nursing homes bracing to lose more workers.

The Biden administration’s mandate, which is to take effect in stages, will ultimately affect about 10 million health care workers in 76,000 hospitals, nursing homes, home-health agencies and other providers that participate in Medicaid and Medicare.

Thursday’s deadline follows a Supreme Court decision on Jan. 13 that blocked a vaccine-or-testing mandate for large employers but upheld a vaccination requirement for health care workers at facilities subsidized by federal funds. These medical facilities will lose funding if they do not comply, federal officials said.

The vaccine requirement goes into effect this week in states that did not challenge the mandate in court, including California, Hawaii, Minnesota and New York, as well as all U.S. territories.

Health care workers in most of the remaining states, where a lower court had blocked the mandate, will have until Feb. 14 to receive a first dose. For Texas, the deadline falls on Feb. 22. To keep their jobs, all health care workers must be fully vaccinated a month after their first dose.

Some in the nursing home industry say the mandate could exacerbate staffing shortages and threaten care for older patients. They have repeatedly pushed for a testing option for their workers.

Mark Parkinson, the chief executive of the American Health Care Association, a trade group representing thousands of nursing homes across the country, said in a statement last week that its members remained “concerned that the repercussions of the vaccine mandate among health care workers will be devastating to an already decimated long-term care work force.”

A little over 80 percent of the staff at the trade group’s nursing homes is fully vaccinated, Mr. Parkinson said. He said providers had made “valiant efforts” to inoculate their staff and should not be penalized.

Mary Susan Tack-Yurek, the chief quality officer and a partner at Quality Life Services, a nursing home chain in western Pennsylvania, said her company had achieved a high vaccination rate without a mandate. More than 96 percent of the chain’s employees are vaccinated or have a medical exemption, she said, a steep rise from October, when less than half of its staff was inoculated.

“We strongly support the vaccine and its effectiveness and authenticity, but we respect individual choice,” she said.

Supporters of mandates say they have spurred millions of hesitant Americans to get their shots and are needed to stem the spread of the virus, especially among vulnerable hospital patients and nursing home residents.

Nursing homes have already exhausted various financial incentives to encourage voluntary vaccination, including lotteries and giveaways, said Dr. Brian McGarry, a health researcher at the University of Rochester who specializes in researching long-term health care.

“I think the only kind of tool that’s left in the policy tool kit is a blanket mandate,” he said.