Newer variants of the coronavirus like Alpha and Delta are highly contagious, infecting far more people than the original virus. Two new studies offer a possible explanation: The virus is evolving to spread more efficiently through air.
The realization that the coronavirus is airborne indoors transformed efforts to contain the pandemic last year, igniting fiery debates about masks, social distancing and ventilation in public spaces.
Most researchers now agree that the coronavirus is mostly transmitted through large droplets that quickly sink to the floor and through much smaller ones, called aerosols, that can float over longer distances indoors and settle directly into the lungs, where the virus is most harmful.
The new studies don’t fundamentally change that view. But the findings signal the need for better masks in some situations, and indicate that the virus is changing in ways that make it more formidable.
“This is not an Armageddon scenario,” said Vincent Munster, a virologist at the National Institute of Allergy and Infectious Diseases, who led one of the new studies. “It is like a modification of the virus to more efficient transmission, which is something I think we all kind of expected, and we now see it happening in real time.”
Dr. Munster’s team showed that small aerosols traveled much longer distances than larger droplets and the Alpha variant — or B.1.1.7, first identified in Britain — was much more likely to cause new infections via aerosol transmission. The second study found that people infected with Alpha exhaled about 43 times more virus into tiny aerosols than those infected with older variants.
The studies compared Alpha with the original virus or other older variants. The results may also explain why the Delta variant is so contagious — and why it displaced all other versions of the virus.
“It really indicates that the virus is evolving to become more efficient at transmitting through the air,” said Linsey Marr, an expert in airborne viruses at Virginia Tech who was not involved in either study. “I wouldn’t be surprised if, with Delta, that factor were even higher.”
The tools at our disposal all still work well to halt the spread. Even loosefitting cloth and surgical masks block about half of the fine aerosols containing virus, according to the study of people infected with variants, published this month in the journal Clinical Infectious Diseases.
Still, at least in some crowded spaces, people may want to consider switching to more protective masks, said Don Milton, an aerosol expert at the University of Maryland who led the research.
Nearly all of United Airlines’ 67,000 employees in the U.S. have been vaccinated against Covid-19 after one of the largest and most significant corporate inoculation campaigns in the United States.
The push came out of sheer frustration with the deadly consequences of the disease, Scott Kirby, chief executive of United Airlines, told The Times on Thursday.
Mr. Kirby said he reached a breaking point over the summer, after finding out that a 57-year-old United pilot had died after contracting the coronavirus. “We concluded enough is enough,” he said. “People are dying, and we can do something to stop that with United Airlines.”
At the time, Mr. Kirby estimated that about 70 percent of the airline’s workers were vaccinated. To raise that level, the company announced a vaccine mandate in early August and offered incentives, like extra pay or vacation days for compliance. United also reached out to the labor unions representing its workers. Still, some employees have resisted, and the company is weighing stricter measures.
About 2,000 employees have applied for medical or religious exemptions, though their fate remains unclear as United fights a lawsuit over its plan to place them on temporary leave. A few hundred more failed to comply with the mandate and could be fired in coming weeks.
Deaths in the United States from the coronavirus surpassed 700,000 on Friday, according to a New York Times database, a milestone that few experts had anticipated months ago when vaccines became widely available to the American public.
An overwhelming majority of Americans who have died in recent months, a period in which the country has offered broad access to shots, were unvaccinated. The United States has had one of the highest recent death rates of any country with an ample supply of vaccines.
The new and alarming surge of deaths this summer means that the pandemic has become the deadliest in American history, overtaking the toll from the influenza pandemic of 1918 and 1919, which killed about 675,000 people.
The recent virus deaths are distinct from those in previous chapters of the pandemic, an analysis by The New York Times shows. People who died in the last three and a half months were concentrated in the South, a region that has lagged in vaccinations; many of the deaths were reported in Florida, Mississippi, Louisiana and Arkansas. And those who died were younger: In August, every age group under 55 had its highest death toll of the pandemic.
The United States government has not closely tracked the vaccination status of everyone who has been infected with the virus, but the Centers for Disease Control and Prevention has so far identified 2,900 people who were vaccinated among the 100,000 who died of Covid since mid-June.
Vaccines have been proven highly effective in preventing severe illness and death, and a study from the C.D.C. that was published in September found that after Delta became the dominant variant, unvaccinated people were more than 10 times as likely to die of the virus as the vaccinated were. The study, which spanned from April to mid-July, used data from 10 states, New York City, Los Angeles County and King County, Wash., which includes Seattle.
The pace of death has quickened, then slowed, then quickened again over the past 18 months as the virus has rippled across America in waves.
The most recent 100,000 deaths occurred over more than three months, a considerably slower pace than when the pandemic reached its peak last winter. During that earlier surge, just 34 days elapsed between the nation’s 400,000th and 500,000th death.
The outsize impact on the South propelled Mississippi ahead of New York and New Jersey for the most coronavirus deaths relative to population throughout the pandemic. Before the Delta surge, the worst-hit states had been mostly Northeastern states that suffered dire early outbreaks, as well as Arizona. But Louisiana and Alabama have become two of the five states with the highest proportion of Covid deaths.
WASHINGTON — Justice Sonia Sotomayor on Friday allowed New York City to require adults working in its public schools to be vaccinated against the coronavirus.
Justice Sotomayor, who oversees the federal appeals court in New York, turned down a request for emergency relief shortly before the mandate became effective on Friday evening. She acted on her own, without referring the application to the full Supreme Court, asking city officials for a response or providing reasoning. All of those moves were indications that the application was not on solid legal footing.
The teachers and school staff challenging the mandate argued that they were being treated differently from other city workers. The mandate, their lawyers told Justice Sotomayor, “will force thousands of unvaccinated public-school employees to lose their jobs — while other municipal employees, including those who have significant contact with children, are allowed to opt-out of the vaccine mandate through weekly Covid-19 testing.”
The challengers added that the mandate violated what they called their “fundamental right to pursue an occupation.”
In refusing to block the mandate, Judge Brian M. Cogan of the Federal District Court in Brooklyn wrote in an earlier ruling that it was “a rational policy decision surrounding how best to protect children during a global pandemic.”
He added that the challengers could seek employment elsewhere.
Judge Cogan wrote that city officials had made a defensible policy decision given the public health crisis.
“Public school students have already endured two school years that were mired by disruption, leaving many students far behind,” he wrote. “Minimizing interruption by providing a safe environment for these students is also a legitimate and important governmental purpose. Although plaintiffs argue that masks and testing adequately can advance this objective, it is not irrational for defendants to conclude the vaccine mandate better enhances this purpose.”
IN CASE YOU MISSED IT
A survey found that more parents were willing to vaccinate their children for the coronavirus in mid-September than were willing to do so in July, a shift that coincided with schools reopening in the middle of a wave of hospitalizations and deaths caused by the highly contagious Delta variant.
The latest monthly survey by the Kaiser Family Foundation also found that about one in four U.S. parents reported that a child of theirs had to quarantine at home because of a possible exposure to Covid-19 since the beginning of the school year. That was even as two-thirds of parents said they felt that their school was taking appropriate measures to contain spread.
The Pfizer vaccine, already in use for older children and adults, was authorized in mid-May for children age 12 to 15, and the report suggests that parents of children in that age group and older are slowly becoming more comfortable with it. Pfizer and BioNTech announced on Tuesday that they had submitted data to the Food and Drug Administration indicating that their vaccine is safe and effective in children ages 5 to 11.
According to federal data, 57 percent of children ages 12 to 17 have received at least one dose of the vaccines. And the survey found that parents of children ages 5 to 11 increasingly report favoring the vaccine as well. Thirty-four percent of those parents said they would have their children vaccinated as soon as possible, up from 26 percent in July.
Another survey about vaccine attitudes released on Tuesday, also conducted by the Kaiser Family Foundation, showed that fear of the Delta variant was the leading reason that people decided to get vaccinated this summer and why most said they would get boosters when eligible.
Here’s what else happened this week:
President Biden received a Pfizer-BioNTech booster shot on Monday, and he urged more Americans to get their first vaccine doses. “Let me be clear,” Mr. Biden said. “Boosters are important. But the most important thing we need to do is get more people vaccinated. The vast majority of Americans are doing the right thing.”
The Pan American Health Organization has struck a deal with the Chinese manufacturer Sinovac to buy millions of doses of Covid-19 vaccine for countries in Latin America and the Caribbean, as part of an effort to make more shots available in a region where access has been highly unequal. The agency is negotiating with two other manufacturers and expecting to announce new deals soon, it said on Wednesday.
YouTube said it was banning the accounts of prominent anti-vaccine activists as part of an effort to remove all content that falsely claims that approved vaccines are dangerous. In a blog post, the company said it would remove from its platform videos claiming that vaccines do not reduce rates of transmission or contraction of disease, and content that includes misinformation on the makeup of the vaccines. Among the prominent anti-vaccination activists whose accounts were blocked are Joseph Mercola, Robert F. Kennedy Jr., Erin Elizabeth and Sherri Tenpenny.
Australia will moved up its plan to ease travel restrictions into and out of the country in November, the second time in 10 days the country accelerated its easing of restrictions.
Vietnam, the second-biggest supplier of apparel and footwear to the United States after China, is grappling with a huge case surge driven by the Delta variant. With the holiday season approaching, many American retailers are anticipating delays and shortages of goods, along with higher prices tied to labor and already skyrocketing shipping costs.
Dollar stores, which have benefited from the prevalence of poverty and disinvestment in inner cities and rural America, are stumbling in this stage of the pandemic.
Their business models, which rely on relatively cheap labor and inexpensive goods, are designed for them to flourish even when their core customers are hurting financially. But they’re less well equipped for the surreal economy of today, when workers are quitting in protest and a single coronavirus case on a container ship can cause a two-month delay in getting Chinese-made merchandise to the United States.
“This is another case of the pandemic laying bare the underlying vulnerabilities in how we’ve set up our economy,” said Stacy Mitchell, a director of the Institute for Local Self-Reliance, an advocacy group that is critical of many large corporate retailers.
Sales are slowing and some measures of profit are shrinking as the industry struggles with a confluence of challenges. They include burned-out workers, pressure to increase wages, supply chain problems and a growing number of cities and towns that are rejecting new dollar stores because they say the business model harms their communities.
The Food and Drug Administration on Friday scheduled three days of public meetings with its panel of independent vaccine experts for later this month, as the agency prepares to make high-profile decisions on whether to authorize emergency use of the Pfizer-BioNTech vaccine for children ages 5 to 11 and booster shots for adult recipients of the Moderna and Johnson & Johnson vaccines.
The F.D.A. typically issues its decisions within a few days of advisory committee meetings, during which members discuss safety and efficacy data. The timing of the upcoming meetings indicates that the agency intends to move quickly to decide whether to authorize both the booster and children’s shots.
The committee will meet on Oct. 14 and 15 to discuss booster doses, and is tentatively scheduled to discuss Pfizer’s pediatric vaccine on Oct. 26, the agency said.
“It’s critical that as many eligible individuals as possible get vaccinated as soon as possible,” Dr. Peter Marks, the agency’s top vaccine regulator, said in a statement.
He added that “the available data make clear that protection against symptomatic Covid-19 in certain populations begins to decrease over time, so it’s important to evaluate the information on the use of booster doses in various populations.”
The decision to have the committee discuss the evidence for Moderna and Johnson & Johnson booster shots two weeks before it does so for Pfizer’s children’s vaccine appears to reflect the F.D.A.’s priorities and the availability of data. But the agency’s decisions on those emergency use authorizations could come in quick succession.
Pfizer and BioNTech have yet to formally ask the F.D.A. to authorize emergency use of their vaccine for pediatric doses; they are expected to do so next week, according to people familiar with the companies’ plans. If regulators grant that request, it could help protect as many as 28 million children and ease the anxiety of parents across the nation. Dr. Scott Gottlieb, a Pfizer board member, has said the F.D.A. could decide as early as Halloween.
Children rarely become severely ill from the coronavirus, but the Delta variant drove nearly 30,000 of them into hospitals in August. Over the course of the pandemic, at least 125 children ages 5 to 11 have died from Covid, and nearly 1.7 million others in that age group have been infected with the virus.
They account for 5 percent of Covid cases and 9 percent of the nation’s population, according to the Centers for Disease Control and Prevention.
Amy Schoenfeld Walker contributed reporting.
Merck on Friday announced that its new pill to treat Covid-19 reduced the risk of hospitalization and death by about 50 percent. Merck plans to seek emergency authorization for the antiviral pills to be used in the United States.
Here’s what to know.
Who will get the pills?
The pills are meant for people who are sick with Covid but are not in the hospital. Merck’s Phase 3 clinical trial enrolled only people considered high risk, such as older people or those with medical conditions like diabetes or heart disease. Initially, the drug might only be available for those people, but experts expect it to eventually become more widely available.
The pills are designed to be taken as soon as possible once a person shows symptoms of having Covid — a time when the virus is replicating rapidly and the immune system has not yet mounted a defense. In Merck’s trial, volunteers had to have shown symptoms within the past five days, and some researchers think the pills must be taken even earlier to be most effective.
When will the pills become available?
Merck said on Friday that it plans to seek emergency authorization from the Food and Drug Administration as soon as possible. Regulators could then authorize the drug before the end of this year, if all goes well.
Dr. Anthony S. Fauci, President Biden’s top medical adviser for the coronavirus, said at a White House briefing on Friday that he could not give a specific timeline for approval.
Sheryl Gay Stolberg contributed reporting.
Disney Theatrical Productions announced that “Aladdin,” which had resumed performances on Broadway this week for the first time since the pandemic hit, was canceling all of its shows starting Friday night through Oct. 10 after “breakthrough Covid-19 cases were detected within the company.”
“Aladdin” isn’t planning another show until Oct. 12. On Tuesday, it held its first performance since Broadway was forced to close in March 2020. The show was canceled on Wednesday because of several positive coronavirus tests, but was able to resume Thursday at the New Amsterdam Theater — for what turned out to be just one night.
An epidemiologist working with the production said the cases were among vaccinated people, and that the 12-day pause was needed to allow them to recover and avoid further spread of the virus.
Disney said in a statement that it was refunding purchased tickets.
All Broadway companies — cast and crew — are required to be fully vaccinated, as are all Broadway audiences. When breakthrough cases occur, some productions have been able to keep going by using understudies. For example, “Waitress” had a positive test in its cast before its first performance, but was able to use testing to determine that the rest of the cast was negative, allowing the performance to proceed with an understudy.
The Broadway League announced on Friday an extension of their vaccine and masking requirements through the end of the year, which will apply in all 41 Broadway theaters. Patrons over the age of 12 must be vaccinated, testing is required for those 12 and under, and all attendees must be masked.
“Aladdin” had been dealing with coronavirus complications in the run-up to its reopening performance. The raucous first night performance, with an audience that included Kristin Chenoweth and the show’s composer, Alan Menken, and librettist, Chad Beguelin, featured three understudies. The crowd didn’t seem to mind — “Friend Like Me,” the Genie’s big production number, brought the audience to its feet. Michael James Scott, the actor playing the Genie, had stood to the side of the stage, breathless, before shouting to the audience, by way of explanation, “18 months, people! 18 months!”
Now it will be a little longer.