Covid-19 Live Updates: Texas Vaccine Mandates, J&J and Moderna Boosters

Ad Blocker Detected

Our website is made possible by displaying online advertisements to our visitors. Please consider supporting us by disabling your ad blocker.

ImageCredit…Bess Adler for The New York Times

In documents released Tuesday morning, Moderna argued that the Food and Drug Administration should authorize a half-dose of its coronavirus vaccine as a booster shot for recipients at least six months after the second dose, citing evidence that the vaccine’s potency against infection wanes over time. The agency noted in its own analysis that, overall, available data show Moderna and the other vaccines “still afford protection against severe Covid-19 disease and death in the United States.”

Moderna cited the rate of breakthrough infections, “real world evidence of reduced effectiveness against the Delta variant,” and falling levels of neutralizing antibodies from its vaccine six to eight months after a second dose. The company said its clinical trial studies showed that a third injection boosted antibody levels — one measure of the immune system’s response — higher than what they had been before the second dose.

The documents were released by the F.D.A. ahead of a two-day meeting of the agency’s advisory committee, scheduled for Thursday and Friday. In its own briefing document for the committee, also released Tuesday, the F.D.A. summarized the data without taking a position.

The committee is expected to vote on whether to recommend emergency authorization of boosters of Moderna’s and Johnson & Johnson’s vaccines. While the panel’s votes are not binding, regulators typically follow them.

Moderna did not try to argue that its vaccine is waning now against severe disease or hospitalization, and the existing data does not appear to support that claim. That distinguishes Moderna’s application from Pfizer-BioNTech’s last month.

In its document, the F.D.A. said: “Some real world effectiveness studies have suggested declining efficacy of Moderna Covid-19 vaccine over time against symptomatic infection or against the Delta variant, while others have not.”

The agency said “there are many potentially relevant studies” and it has not independently reviewed the underlying data or conclusions of each one.

The F.D.A. and the Centers for Disease Control and Prevention decided to authorize boosters for many but not all Pfizer-BioNTech vaccine recipients. The eligible include those 65 or older, who live in long-term care facilities, have underlying medical conditions or are at higher risk of exposure to the virus because of their jobs or institutional settings. The last group includes health care workers, teachers and prisoners.

In the document released Tuesday, the F.D.A. proposed the outside experts consider essentially the same eligibility groups for Moderna recipients. But people familiar with the deliberations said that federal officials may also ask the committee to consider broadening eligibility for boosters of both vaccines to include more middle-aged people.

Moderna said it compared using a full dose and a half dose as a booster, and found that a half dose boosted antibody levels well with lower risks of adverse side effects. It also tried to make a point about conserving limited supplies, saying a half-dose “would result in a substantial increase in the world wide supply” of its vaccine.

Several independent studies have tried to estimate how long Moderna’s two-dose vaccine remains effective against mild, moderate and severe Covid. One looked at Covid cases last summer among more than 15,000 volunteers in Moderna’s clinical trial, some of whom had been vaccinated a full year earlier. Researchers compared Covid cases in July and August among trial participants who had been fully vaccinated between July and October 2020 with cases among those who were fully vaccinated between December 2020 and March 2021.

Those who got vaccinated later had a 36 percent lower rate of disease. But Dr. Hana M. El Sahly, a professor of molecular virology at Baylor College of Medicine and one of the lead researchers, said the study did not find a statistically significant difference between the two groups in cases of severe Covid — of which there were only 19.

Overall, she said, “the findings do not indicate that a booster is needed.” The study was backed by the National Institutes of Health, researchers said.

Another recent C.D.C. study reviewed case files of nearly 3,700 patients in 21 different hospitals from March to August. Researchers found that of the three vaccines available in the United States, Moderna’s vaccine held up best over six months.

The researchers said that Moderna was 93 percent effective against hospitalization, compared with 88 percent for Pfizer and 71 percent for Johnson & Johnson. Pfizer’s efficacy dropped significantly after four months, to 77 percent, while Moderna’s basically held steady, they said.

Given the dearth of data showing that Moderna’s protection weakens against severe disease, the committee’s deliberations about boosters for Moderna recipients will likely revolve around other key questions.

First, is there a need to “harmonize” U.S. booster strategy, making recipients of all three vaccines eligible even if they keep their potency for different periods of time? Some federal officials argue that with many Pfizer recipients already receiving boosters, the answer is yes.

“We’re in this very complicated situation right now: People are going into pharmacies or places where vaccines are available and saying, ‘I want my third dose of Moderna, or I want my second dose of J.&J.,” said Dr. H. Cody Meissner, an infectious disease expert at Tufts Medical Center who serves on the F.D.A. panel. “I don’t think anyone has much doubt that we will need a booster dose for these vaccines. What we don’t know is: How urgent is the need?”

Another question is whether Moderna will eventually wane against severe disease. Some booster advocates argue that Moderna is following the same path as Pfizer’s vaccine, just more slowly, because its initial dosage is significantly stronger and the interval between the first two shots is longer.

Committee members are also expected to debate whether Moderna recipients should be given a booster simply to protect them against the risk of mild or moderate disease, or to try to disrupt transmission of the virus.

“The fundamental issue is, what are we trying to do?” said Dr. El Sahly. “Both Moderna and Pfizer seem to have waned when it comes to mild to moderate disease, especially with the Delta variant.

“So, if that’s the goal, a booster is needed. If we want to prevent only severe disease that lands people in the hospital, that’s a different mathematics.”

Credit…Matthew Busch for The New York Times

An order issued on Monday by the governor of Texas, barring nearly all Covid-19 vaccine mandates in the state, appears sweeping. But legal experts say that it does not supersede President Biden’s orders requiring vaccine mandates for many kinds of employees, and that it is likely to be challenged in court, where the case law so far has been heavily in favor of the validity of vaccine requirements.

The order by Gov. Greg Abbott of Texas, a Republican, bars vaccine mandates by any “entity” — including private employers, who were not covered by his previous orders forbidding mandates. States like Florida have also acted to ban public agencies and private businesses from requiring vaccination, and those bans are also likely to end up in court, experts say.

“Texas has just set itself up for a grand political show, but not a potentially legally sound initiative to stop all vaccine mandates,” said James Hodge, the director of the Center for Public Health Law and Policy at Arizona State University. “It boils down to a lot more politics than law.”

Courts in the United States have a long history of upholding vaccine mandates, Mr. Hodge said, and of ruling that protecting public health takes precedence over personal choice.

“That individual right to liberty has never gone that far to actually engage in behaviors that directly impact the public’s health,” said Mr. Hodge.

The right of the government to impose vaccine mandates has been established at least since 1904, when the Supreme Court ruled that Cambridge, Mass., could require all adults there to be vaccinated against smallpox. Later court cases set the legal groundwork for vaccine mandates in schools, health care and other fields, Mr. Hodge said.

The Texas order also ramps up an emerging battle between Republican governors and President Biden, who is testing the limits of presidential power by asserting executive authority to require Covid-19 vaccines for workers in the federal government and the health care industry.

The president has also moved to require that all companies with more than 100 workers maintain safe workplaces through vaccination or weekly testing, relying on the federal government’s power to regulate commerce and the Occupational Safety and Health Act of 1970.

Jen Psaki, the White House press secretary, said on Tuesday that the president’s legal authority to issue mandates “overrides state law,” and that “to get out of this pandemic, the president will use every lever at his disposal.”

Republican governors like Mr. Abbot and Ron DeSantis of Florida have accused Mr. Biden of overreach. Mr. DeSantis said at a news conference on Tuesday that Florida and other states were prepared to mount a legal challenge to Mr. Biden’s mandate for private employers. But the states are likely to lose in court, experts say.

“It’s highly unlikely that you’re going to see any sort of higher-level court consistently agree that this type of intervention exceeds federal authority, when it’s been in place for 50 years,” Mr. Hodge said.

In August, a federal judge ruled against Florida’s ban on “vaccine passport” requirements. Ruling on First Amendment grounds, the judge issued a temporary injunction allowing Norwegian Cruise Line to continue requiring its embarking passengers to show proof of vaccination, despite the state ban.

Credit…Kevin Dietsch/Getty Images

American Airlines and Southwest Airlines, citing federal requirements, said on Tuesday that they would not comply with an order from the governor of Texas barring private employers from mandating coronavirus vaccines in the state.

Gov. Greg Abbott, a strong opponent of vaccine mandates, issued the order on Monday, saying inoculation against Covid-19 should “always be voluntary for Texans.”

“We believe the federal vaccine mandate supersedes any conflicting state laws, and this does not change anything for American,” said a spokeswoman for the airline, which is based in Fort Worth. Southwest, which is based in Dallas, said it would “remain compliant” with the federal mandate.

The Greater Houston Partnership, a business group that counts Exxon Mobil, Chevron and JPMorgan Chase as members, also came out on Tuesday against Mr. Abbott’s order, saying it “does not support Texas businesses’ ability and duty to create a safe workplace.”

President Biden announced last month that federal contractors and their employees would need to be vaccinated, with limited exceptions. Like other major employers, American and Southwest cited that requirement and their status as contractors in announcing that employees must be vaccinated.

Mr. Biden also announced that workers at companies with more than 100 employees would have to be vaccinated or tested regularly, but those requirements are dependent on new rules that the Occupational Safety and Health Administration has not issued yet. That requirement will cover tens of millions of workers, the administration said. Health care workers at institutions that receive funding from Medicaid and Medicare are also required to be vaccinated.

Jen Psaki, the White House press secretary, accused Mr. Abbott on Tuesday of putting “politics ahead of public health” and said federal laws superseded state and local ones.

The administration will continue to pursue the expansive mandates it announced last month, she said, adding that business leaders who had already introduced mandates had reported positive results.

“Beyond the legal aspect, which is unquestionable in our view, the question for any business leader is: What do you want to do to save more lives in your companies?” Ms. Psaki said.

In Florida, another state with a governor who has battled vaccine mandates, the Department of Health issued a notice of violation to Leon County, which encompasses Tallahassee, for violating a ban on “vaccine passports” in the state.

The department said in a release on Tuesday that it was fining the county nearly $3.6 million for requiring 700 government employees to provide their vaccine status and firing 14 who refused to comply. Gov. Ron DeSantis said he wanted to “preserve the ability of Floridians to make their own decisions regarding what shots to take.”

Credit…Andrew Testa for The New York Times

Britain’s initial response to the Covid-19 pandemic “ranks as one of the most important public health failures the United Kingdom has ever experienced,” a parliamentary inquiry has found, blaming the British government for “many thousands of deaths which could have been avoided.”

In a highly critical, 151-page report, two committees of lawmakers wrote that the government’s failure to carry out widespread testing or swiftly impose lockdowns and other restrictions amounted to a pursuit of “herd immunity by infection” — accepting that many people would get the coronavirus and that the only option was to try to manage its spread.

“It is now clear that this was the wrong policy, and that it led to a higher initial death toll than would have resulted from a more emphatic early policy,” the report concluded.

Although many of its findings were already known, the report grew out of the first authoritative investigation of Britain’s pandemic response. The inquiry, led by lawmakers from Prime Minister Boris Johnson’s own Conservative Party, described a litany of failures by his government in the months after the first coronavirus cases were detected in Britain in January 2020.

Britain has experienced one of the worst Covid-19 outbreaks among wealthy nations, with 162,000 deaths officially attributed to the disease. Like many Western democracies, at the outset of the pandemic it struggled to balance individual liberties with strict measures such as lockdowns, and suffered from mismanagement at the top levels of government.

The country has tried to put those missteps behind it, racing ahead last winter and spring as one of the world leaders in vaccinations, with more than three-quarters of people 12 and older having now received two doses of a Covid vaccine. As deaths declined from prior peaks, Britain cast off nearly all restrictions, and even though infections remain high, Mr. Johnson has tried to portray the country as having put the worst of the pandemic behind it.

But as he struggles against a raft of new economic problems, the report renewed criticisms of his government’s handling of the virus. It does not require the government to act, but its findings are likely to influence the public debate for months to come. A full public inquiry promised by Mr. Johnson is not scheduled to begin until next year.

“This report lays bare the failings of the U.K. government to contain Covid, including delayed border measures, nonexistent testing for weeks, lack of P.P.E. for frontline workers and a late lockdown,” said Devi Sridhar, the head of the global public health program at the University of Edinburgh. “Hopefully, lessons will be learned from this.”

Credit…Adam Hunger via Associated Press

The Nets announced Tuesday that they were indefinitely barring Kyrie Irving from all games and practices until he was “eligible to be a full participant.”

Irving, the team’s starting point guard, had faced the prospect of being able to play only on the road with the Nets this season because of local coronavirus ordinances in New York that require most individuals to be at least partially vaccinated to enter facilities such as sports arenas. The Nets play their home games at Barclays Center in Brooklyn.

“Without a doubt, losing a player of Kyrie’s caliber hurts,” Sean Marks, the Nets’ general manager, said at a news conference. “I’m not going to deny that. But at the end of the day, our focus, our coaches’ focus and our organization’s focus needs to be on those players that are going to be involved here and participating fully.”

Irving has not spoken publicly about his vaccination status, asking instead for privacy, and the Nets had danced around the topic for weeks. In response to a question from The New York Times on Tuesday about whether Irving was vaccinated, Marks said: “If he was vaccinated, we wouldn’t be having this discussion. I think that’s probably pretty clear.”

Marks said Irving would not be paid for missed home games, and that the decision to keep Irving away from the team had been made by himself and by Joe Tsai, the Nets’ owner.

“Will there be pushback from Kyrie and his camp? I’m sure that this is not a decision that they like,” Marks said. “Kyrie loves to play basketball, wants to be out there, wants to be participating with his teammates. But again, this is a choice that Kyrie had and he was aware of that.”

Irving missed the Nets’ preseason home-opener against the Milwaukee Bucks after being listed as “ineligible” on the injury report. He also was not with the Nets in Philadelphia for their preseason game against the 76ers on Monday. Asked about his absence before the game, Steve Nash, the Nets’ coach, said: “We’re just trying to take our time to figure out what everything means.”

Irving’s potential absence from home games had created a predicament for the Nets, a team with championship aspirations that had to weigh whether having him around only half the time would be worth it. His teammates had expressed their support for him.

“It’ll work itself out,” James Harden said last week, adding: “I want him to be on the team, of course. He’s been a huge part of our success.”

On Tuesday, Marks said he would be willing to welcome Irving’s return to the team “under a different set of circumstances.”

Barclays Center and Madison Square Garden, where the Knicks play, require all employees and guests 12 and older to show proof of having received at least one vaccine dose, to comply with a city mandate, unless they have a religious or medical exemption. San Francisco has a similar requirement that applies to Chase Center, where the Golden State Warriors play. The mandates in both cities mean that the players from the Knicks, Nets and Golden State cannot play in their teams’ 41 home games without being vaccinated.

The ordinances in New York and San Francisco do not apply to players from visiting teams.

Credit…Yana Paskova for The New York Times

A federal judge ruled on Tuesday that New York State health officials must allow employers to grant religious exemptions to a Covid-19 vaccine mandate for health care workers while a lawsuit challenging the mandate makes its way through the courts.

The judge’s order at least temporarily thwarts part of Gov. Kathy M. Hochul’s effort to require vaccination for all health care workers. It offers a reprieve for thousands of unvaccinated doctors, nurses and support workers who had applied for religious exemptions, and who would have been prevented from working beginning Tuesday if the judge had ruled for the state. The mandate remains in effect for all other health care workers.

A lawyer for a group of workers who are suing the state over the mandate hailed the ruling.

“With this decision, the court rightly recognized that yesterday’s ‘front line heroes’ in dealing with Covid cannot suddenly be treated as disease-carrying villains and kicked to the curb by the command of a state health bureaucracy,” said Christopher Ferrara of the Thomas More Society.

Ms. Hochul, in a statement, indicated the state would appeal.

“My responsibility as governor is to protect the people of this state, and requiring health care workers to get vaccinated accomplishes that,” Ms. Hochul said. “I stand behind this mandate, and I will fight this decision in court to keep New Yorkers safe.”

Former Gov. Andrew M. Cuomo issued the state’s first vaccine mandate for health workers in mid-August; it permitted religious exemptions.

But when Ms. Hochul’s administration issued its own mandate later that month — to take effect this fall — it rescinded the exemptions. That prompted 17 health care workers to sue the state in federal court, on the ground that the mandate conflicted with their religious beliefs.

Between the two governors’ orders, thousands of health care workers across the state had applied for or received a religious exemption.

In his 27-page ruling, Judge David N. Hurd of the Northern District in Utica wrote that New York appeared to overreach by barring all religious accommodations in the mandate. He issued a preliminary injunction preventing the Department of Health from acting against any employer who grants religious exemptions, and wrote that the 17 health care workers were likely to succeed in their case.

“The Department of Health is barred from interfering in any way with the granting of religious exemptions from Covid-19 vaccination going forward, or with the operation of exemptions already granted,” Judge Hurd wrote.

The judge had earlier issued a temporary restraining order barring the state from enforcing the mandate against people with religious objections starting in mid-September; technically, Tuesday’s order extended that ruling. The restraining order effectively allowed many health workers who applied for religious exemptions in New York to continue working even after the mandate went into effect.

In the federal case, titled Dr. A et al v. Hochul, the 17 health care workers argued that they could not consent to be inoculated with vaccines “that were tested, developed or produced with fetal cell lines derived from procured abortions.”

Pope Francis has said that Catholics may get the Covid-19 vaccines; most of the health care workers suing in the case are Catholic. But Judge Hurd did not question whether the health care workers were correct in their religious objections. Instead, he focused on their broader constitutional right to have their religious beliefs considered, and when possible, accommodated.

In his ruling on Tuesday, Judge Hurd looked at how the mandates differed from one governor to the next. “This intentional change in language is the kind of ‘religious gerrymander’ that triggers heightened scrutiny,” the judge wrote.

Credit…Hector Retamal/Agence France-Presse — Getty Images

More than 700 people have applied for spots on a new committee charged with breathing life into the World Health Organization’s stalled inquiry into the origins of the coronavirus pandemic, despite the considerable challenges the investigation presents.

The committee, expected to be announced this week, represents an attempt by the embattled global health body to reset its approach to determining how the pandemic began. Nine months after sending a team of international experts to China, only for its findings to become entangled in geopolitics and trailed by concerns over Beijing’s influence, the W.H.O. is trying to inoculate its latest efforts from the slightest hints of undue deference toward China.

Its new advisory team will include specialists in fields like laboratory safety and biosecurity, a step that analysts say may help placate Western governments pressing for consideration of whether the virus emerged from a lab. And, crucially, the committee will have a mandate to weigh in on the emergence of any new pathogens beyond this novel coronavirus, giving it a permanence that could help insulate it from political squabbling and strengthen the W.H.O.’s hand for future outbreaks.

Maria Van Kerkhove, the W.H.O.’s Covid-19 technical lead, said the group — comprising some two dozen virologists, geneticists, animal experts and safety and security specialists — would help the organization return to its roots amid the rancor and partisanship of the coronavirus origins debate.

But what most needs doing in the hunt for Covid’s origins, many scientists believe, is something that the new advisory group will be powerless to achieve: persuading China to release evidence about the first infections and to let researchers inspect virology labs, bat caves and wildlife farms within its borders.

Credit…Adam Dean for The New York Times

Fully vaccinated travelers from low-risk countries, including the United States and China, would be allowed to visit Thailand without undergoing quarantine starting Nov. 1, under a plan announced by the country’s prime minister, Prayuth Chan-ocha.

Health officials are expected to approve the plan, which calls for the lifting of restrictions for tourists from 10 countries. It would be the first step in a phased reopening strategy that would lead to the resumption of service at entertainment venues as early as Dec. 1, he said in an address Monday evening.

Before the pandemic, Thailand’s economy was highly dependent on tourism and attracted nearly 40 million tourists in 2019, with more than a quarter coming from China. Bangkok, the capital, often ranks in surveys as the world’s most visited city. Thailand was among the most successful countries in containing the virus last year. But it was slow in procuring vaccines and has seen a surge of cases this year.

The prime minister said that Thailand must learn to live with the virus, noting that other nations were already taking steps to reopen to tourists, and that Thailand must act quickly to lure millions of visitors for the New Year holidays.

Under Mr. Prayuth’s plan, fully vaccinated visitors from the 10 countries would be required to show proof of a negative PCR test before departure, and to take another test upon arrival. After testing negative, they would be free to travel around Thailand. Visitors from countries not on the list would still face quarantines and other restrictions.

A ban on restaurants serving alcohol — a rule widely flouted in Bangkok — would remain in place until at least Dec. 1, he said.

In July, Thailand began allowing vaccinated tourists who tested negative to visit the island of Phuket under a program called the Phuket Sandbox. After 14 days, they were allowed to travel freely in Thailand. That period has since been reduced to seven days. Thailand has increased its vaccine supply in recent weeks and launched an aggressive inoculation campaign, vaccinating as many as 1 million people a day.

“The time has come for us to ready ourselves to face the coronavirus and live with it as with other endemic infections and disease,” Mr. Prayuth said.

Credit…Thomas Kienzle/Agence France-Presse — Getty Images

The German company CureVac announced on Tuesday that it was withdrawing its mRNA vaccine for Covid-19 from the approval process in Europe. The company pulled the plug after determining that it might take until June for regulators to make a ruling about the vaccine.

With other mRNA vaccines from Moderna and Pfizer-BioNTech already in wide distribution, the company decided it was time to give up on its initial efforts to address the Covid-19 emergency.

“The pandemic window is closing,” Franz-Werner Haas, CureVac’s chief executive, said in an interview.

The company will also terminate its advance agreement with the European Commission to sell it 405 million doses of the vaccine after approval.

But in the longer term, CureVac is not out of the Covid-19 vaccine business. The company is partnering with the pharmaceutical giant GSK to start a clinical trial of a new version of the vaccine that they hope will be more effective. The companies are also investigating how to combine seasonal booster shots to work against both Covid-19 and influenza.

Founded 20 years ago, CureVac pioneered early research on mRNA vaccines along with the German firm BioNTech and the U.S. company Moderna. At the start of the Covid-19 pandemic, all three companies developed new vaccines against the coronavirus.

While Moderna and BioNTech moved swiftly into clinical trials, CureVac was slower to find partners to support its vaccine’s development. Nevertheless, some experts saw promise in the CureVac shot, hoping that it could help address the global shortfall in Covid vaccines.

The European Medicines Agency gave CureVac special priority for its application, cutting the time needed for authorization. But in June, the company made a disappointing announcement: A clinical trial found that the vaccine’s efficacy was just 48 percent. By comparison, the vaccines from BioNTech and Moderna had efficacies around 95 percent.

Despite that disappointment, CureVac went ahead with its application for authorization in Europe, and submitted a final data package in September. In its updated application, CureVac asked that the vaccine be considered only for people 18 to 60 years old. In that group, the clinical trial had found a moderately higher vaccine efficacy, of 53 percent.

The European regulators’ response was less than encouraging. “We were not being lined up for emergency review,” said Dr. Klaus Edvardsen, the company’s chief development officer.

CureVac’s Covid-19 vaccine is now the seventh to be abandoned after entering clinical trials. Last month, Sanofi announced it was giving up on its mRNA vaccine.

But CureVac’s newer version may have more success. In August, the company shared the results of an experiment on monkeys, showing that the new vaccine generated 10 times as many antibodies against the coronavirus as the original one did. CureVac will begin testing it in people in the next couple of months.

Dr. Haas said the company’s strategy is now “to be fast with a second generation rather than to be very late with the first generation.”

Correction: Oct. 12, 2021

An earlier version of this article misstated the efficacy of the CureVac vaccine. It was 48 percent, not 47. It also misstated the age range for which the company asked regulators to consider vaccine approval. It was ages 18 to 60, not under 65.

Credit…Seth Wenig/Associated Press

In their struggle to convince holdouts to get vaccinated against Covid, governments around the world are embracing vaccine mandates.

The push to get people vaccinated has largely shifted from offering incentives, like cash payouts or free drinks, to issuing mandates and restricting the access of the unvaccinated to many venues and activities.

Care to sip an espresso indoors at a cafe in Paris? You will need to provide proof of vaccination or a fresh negative coronavirus test, for which unvaccinated people will have to pay beginning on Oct. 15.

Want to work in settings like offices, factories, shops and restaurants in Italy? Starting later this month, you will need to have recently recovered from Covid-19, provide proof of having received at least one dose of a vaccine, or get a coronavirus test every two days. In areas of high coronavirus transmission in Greece, live music is returning indoors to restaurants and bars for a two-week trial, but the unvaccinated will not be admitted.

Italian and French officials announced their measures in July. Greece announced its shift last week. In early August, New York became the first U.S. city to require proof of vaccination for indoor dining, gyms and movie theaters.

Since then, San Francisco, Los Angeles and other cities have announced their own vaccine requirements to engage in public activities.

As the latest wave of infections has begun to wane around much of the U.S., President Biden’s administration has increasingly turned to mandates, drawing fire in the process from many Republican leaders who perceive them as government overreach. On Thursday, he urged private employers to impose mandates of their own as the Occupational Safety and Health Administration works out the details of a vaccine or testing requirement for companies with more than 100 employers.

Vaccine mandates have sparked resentment and refusal to comply from the unvaccinated.

France’s restrictions spurred large protests this summer, but those protests have mostly cooled, and as of Oct. 7, 67 percent of the population was fully vaccinated, more than double the level from early July, according to the Our World in Data project at the University of Oxford. An additional 8.3 percent were partly vaccinated as of Oct. 7.

Vaccine requirements remain politically toxic in some parts of the United States. Republican governors like Greg Abbott of Texas and Ron DeSantis of Florida have enacted rules that penalize businesses that require proof of vaccination and prohibit local governments from mandating such requirements.

On Monday, Mr. Abbott signed an executive order that broadened a previous ban on vaccine mandates by barring private companies from imposing them.

“The COVID-19 vaccine is safe, effective, and our best defense against the virus, but should remain voluntary and never forced,” the governor said in a statement.

The A.C.L.U., on the other hand, has defended vaccine mandates, saying they protect the civil liberties the organization defends.

“They protect the most vulnerable among us, including people with disabilities and fragile immune systems, children too young to be vaccinated and communities of color hit hard by the disease,” David Cole, the national legal director of the A.C.L.U., and Daniel Mach, director of its program on freedom of religion and belief, wrote in a New York Times editorial in September.

Some organizations that encourage vaccinations feel that mandates could be counterproductive, like the Wyoming Hospital Association. Eric Boley, the association’s president, said that vaccination was critical, especially for health workers, but that mandates could drive away staff that Wyoming’s hospitals urgently need.

Credit…Joe Raedle/Getty Images

By the holiday season, flying will have changed significantly for Americans returning to the United States from abroad. They will be asked to show proof that they are vaccinated, to commit to two coronavirus tests if they are not and to participate in a new contact tracing system.

For Americans traveling within the United States, however, none of this applies. As airlines prepare for what’s expected to be the biggest travel rush of the past two years, domestic travel — aside from a mask mandate and some restrictions on alcohol — will be largely the same as it was before the pandemic: packed cabins and no testing or proof of vaccination required.

Whether this is a symptom of denial or a sign of progress depends on whom you ask. Senator Dianne Feinstein, Democrat of California, recently telegraphed her position when she proposed a bill that would require passengers on domestic flights to be fully vaccinated, to have recently tested negative or to have a certificate of recovery from the virus.

“We know that air travel during the 2020 holiday season contributed to last winter’s devastating COVID-19 surge,” Ms. Feinstein said in a statement. “We simply cannot allow that to happen again.”

Dr. Anthony S. Fauci, President Biden’s top medical adviser, has said he personally supports requiring proof of vaccination for domestic air travel, a policy that Canada will begin putting in place on Oct. 30. But the White House has said it is focused on other strategies for encouraging broad vaccination.

Credit…Fabio Bucciarelli for The New York Times

On Jan. 9, 2020, about a week after the world first learned of a mysterious cluster of pneumonia cases in central China, authorities announced that scientists had found the culprit: a novel coronavirus.

It was a sobering announcement, and an unnervingly familiar one. Nearly two decades earlier, a different coronavirus had sped around the world, causing a lethal new disease — severe acute respiratory syndrome, or SARS. It killed 774 people before health officials contained it.

But even as scientists worried that history may be repeating itself, there was one glimmer of hope. Although all viruses evolve, coronaviruses are known to be relatively stable, changing more slowly than the common flu.

What many scientists had not counted on was unchecked global spread. Over the following weeks, the new virus, SARS-CoV-2, skipped from Wuhan, China, to a cruise ship in Japan, to a small town in northern Italy and to a biotechnology conference in Boston. Country by country, global coronavirus trackers turned red.

To date, more than 237 million people have been infected with the virus, and 4.8 million have died — 700,000 in the United States alone.

With every infection come new opportunities for the virus to mutate. Now, nearly two years into the pandemic, we are working our way through an alphabet of new viral variants: fast-spreading Alpha, immune-evading Beta, and on through Gamma, Delta, Lambda and, most recently, Mu.

Even for a virus, evolution is a long game, and our relationship with Covid-19 is still in its infancy. We are extremely unlikely to eradicate the virus, scientists say, and what the next few years — and decades — hold is difficult to predict.

But the legacy of past epidemics, as well as some basic biological principles, provides clues to where we could be headed.

Credit…Grant Hindsley for The New York Times

It’s difficult to parse how immunity from infection from the coronavirus and from vaccination compare. Dozens of studies have delved into the debate, and have drawn contradictory conclusions.

Some consistent patterns have emerged. Two doses of an mRNA vaccine produce more antibodies, and more reliably, than an infection does. But the antibodies from a previous infection are more diverse, capable of fending off a wider range of variants, than those produced by vaccines.

Studies touting the durability and strength of natural immunity are hobbled by one crucial flaw. They are, by definition, assessing the responses only of people who survived Covid-19.

Only 85 percent to 90 percent of people who test positive for the virus and recover have detectable antibodies to begin with. The strength and durability of the response is variable.

For example, while the immunity gained from vaccines and infection is comparable among younger people, two doses of the mRNA vaccines protected adults older than 65 better than a prior infection did.

Research published in May showed a stepwise increase in the level of antibodies with rising severity of infection. About 43 percent of recovered people had no detectable neutralizing antibodies — the kind needed to prevent reinfection — according to one study. The antibodies drop to undetectable levels after about two months in about 30 percent of people who recover.

Several studies have now shown that reinfections, at least with the earlier versions of the virus, are rare.

At the Cleveland Clinic, none of 1,359 health care workers who remained unvaccinated after having Covid-19 tested positive for the virus over many months.

But the clinic tested only people who were visibly ill, and may have missed reinfections that did not produce symptoms. The participants were 39 years old on average, so the results may not apply to older adults, who would be more likely to become infected again.

Credit… Edward “Doc” Rogers/MediaNews Group/Oakland Tribune via Getty Images

Covid-19’s waves of destruction have inflicted their own kind of despair on humanity in the 21st century, leaving many to wonder when the pandemic will end.

“We tend to think of pandemics and epidemics as episodic,” said Allan Brandt, a historian of science and medicine at Harvard University. “But we are living in the Covid-19 era, not the Covid-19 crisis. There will be a lot of changes that are substantial and persistent. We won’t look back and say, ‘That was a terrible time, but it’s over.’ We will be dealing with many of the ramifications of Covid-19 for decades, for decades.”

Especially in the months before the Delta variant became dominant, the pandemic seemed like it should be nearly over.

“When the vaccines first came out, and we started getting shots in our own arms, so many of us felt physically and emotionally transformed,” said Dr. Jeremy Greene, a historian of medicine at Johns Hopkins University School of Medicine. “We had a willful desire to translate that as, ‘The pandemic has ended for me.’”

He added, “It was a willful delusion.”

That is a lesson from history that is often forgotten, Frank Snowden, a historian of medicine at Yale University, said: how difficult it is to declare that a pandemic has ended.

It may not be over even when physical disease, measured in illness and mortality, has greatly subsided. It may continue as the economy recovers and life returns to a semblance of normality. The lingering psychological shock of having lived in prolonged fear of severe illness, isolation and painful death takes long to fade.

Credit…Emily Kask for The New York Times

Many law enforcement officers in the United States resist coronavirus vaccination even though Covid-19 has killed more law enforcement officers than any other work-related cause since the start of the pandemic.

More than 460 American law enforcement officers have died from Covid-19 infections tied to their work since the pandemic began, according to the Officer Down Memorial Page, making the coronavirus by far the most common cause of duty-related deaths in 2020 and 2021. More than four times as many officers have died from Covid-19 as from gunfire during the pandemic. There is no comprehensive accounting of how many American police officers have been sickened by the virus, but departments across the country have reported large outbreaks in the ranks.

While the virus has ravaged policing, persuading officers to take a vaccine has often been a struggle, even though the shots have proven to be largely effective in preventing severe disease and death.

Health departments generally do not publish vaccination data by occupation, but some cities have released figures showing that police department employees have been vaccinated at lower rates than most other government workers, and at lower rates than the general public. In Los Angeles, where vaccines are required for city workers, more than 2,600 employees of the police department said they intended to seek a religious exemption, though almost all major religious denominations support vaccines.

Some elected officials say police officers have a higher responsibility to get vaccinated because they are regularly interacting with members of the public and could unknowingly spread the virus. The debate echoes concerns from earlier in the pandemic, when police officers in some cities resisted wearing masks in public.

Yet as more departments in recent weeks have considered requiring members to be vaccinated, officers and their unions have loudly pushed back, in some cases threatening resignations or flooding systems with requests for exemptions.