Brittany Siguenza, 5, watching her mother receive a dose of the Moderna vaccine in Revere, Mass., on Friday.
CJ Gunther/EPA, via Shutterstock

The drug company Moderna has begun a study that will test its Covid vaccine in children under 12, including babies as young as six months, the company said on Tuesday.

The study is expected to enroll 6,750 healthy children in the United States and Canada. Moderna declined to say how many had already signed up or received the first shots, according to a spokeswoman, Colleen Hussey.

“There’s a huge demand to find out about vaccinating kids and what it does,” said Dr. David Wohl, the medical director of the vaccine clinic at the University of North Carolina, who is not involved the study.

In a separate study, Moderna is testing its vaccine in 3,000 children ages 12 to 17, and may have results for that age group by summer. The vaccine would then have to be authorized for use in children, so it would not be immediately available.

Many parents want protection for their children, and vaccinating children should help to produce the herd immunity considered crucial to stopping the pandemic. The American Academy of Pediatrics has called for expansion of vaccine trials to include children.

Vaccine side effects like fever, sore arms, fatigue and achy joints and muscles can be more intense in children than in adults, and doctors say it is important for parents to know what to expect after their children are inoculated.

Each child in Moderna’s study will receive two shots, 28 days apart. The study will have two parts. In the first, children aged 2 years to less than 12 may receive two doses of 50 or 100 micrograms each. Those under 2 years may receive two shots of 25, 50 or 100 micrograms. (One adult dose is 100 micrograms.)

In each group, the first children inoculated will receive the lowest doses and will be monitored for reactions before later participants are given higher doses.

Then, researchers will perform an interim analysis to determine which dose is safest and most likely to be protective for each age group.

Children in part 2 of the study will receive the doses selected by the analysis — or placebo shots consisting of salt water.

Moderna developed its vaccine in collaboration with the National Institute of Allergy and Infectious Diseases. The company and the institute are also working together on the study, along with the federal Biomedical Advanced Research and Development Authority.

The children will be followed for a year, to look for side effects and measure antibody levels that will help researchers determine whether the vaccine appears to provide protection. The antibody levels will be the main indicator, but the researchers will also look for coronavirus infections, with or without symptoms.

Dr. Wohl said the study appeared well designed and likely to be efficient, but he questioned why the children were to be followed for only one year, when adults in Moderna’s study are followed for two years. He also said he was somewhat surprised to see the vaccine being tested in children so young this soon.

“Should we learn first what happens in the older kids before we go to the really young kids?” Dr. Wohl asked. Most young children do not become very ill from Covid, he said, though some develop a severe inflammatory syndrome that can be life threatening.

Johnson & Johnson has also said it would test its coronavirus vaccine in babies and young children after testing it first in older children.

Pfizer and BioNTech are testing their vaccine in children ages 12 to 15, and have said the plan is to move to younger groups; the product is already authorized for use in those 16 and up in the United States.

Last month, AstraZeneca began testing its vaccine in Britain in children 6 years and older.

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Members of the World Health Organization backed the AstraZeneca vaccine, despite a growing number of countries that have suspended the use of the vaccine.Alessandro Grassani for The New York Times

LONDON — After the European Union’s biggest countries suspended the use of AstraZeneca’s vaccine, the continent’s top drug regulator pushed back hard on Tuesday against fears about the shot, saying there was no sign of its causing rare but dangerous problems, and strong evidence that its lifesaving benefits “outweigh the risk of the side effects.”

The reassurance by Emer Cooke, executive director of the European Medicines Agency, came a day after Germany, France, Italy, Spain and others halted use of the vaccine, even as Europe faces a third wave of the virus, hundreds of millions of its people are still constrained by severe pandemic restrictions and many are facing the prospect of rules tightening even more.

The vaccine suspensions were a startling about-face after government officials had spent days assuring the public of the vaccine’s safety. After Germany indicated that it would put the shots on hold, others quickly followed, wanting to present a united front and avoid the political fallout from being an outlier if real problems with the vaccine emerged.

Concerns about possible rare side effects like blood clots and abnormal bleeding have rattled confidence in the vaccine and delayed the already slow and troubled inoculation campaign in Europe. No country in the European Union is on pace to reach its goal of vaccinating 70 percent of its population by September.

The European Medicines Agency was still studying concerns about the ill effects reported in a small number of people who received the AstraZeneca shot, but there was “no indication that vaccination has caused these conditions,” Ms. Cooke said on Tuesday at a news conference.

“While the investigation is ongoing, we are currently still firmly convinced that the benefits of the AstraZeneca vaccine in preventing Covid-19, with its associated risk of hospitalization, outweigh the risk of the side effects,” she added.

Ms. Cooke’s reassurance added to the confusion and mixed messages surrounding Europe’s vaccine rollout. The stakes could scarcely be higher: delaying inoculation for tens of millions of people, though others will continue to receive vaccines made by other companies, and possibly undermining faith worldwide in the AstraZeneca shot.

The AstraZeneca vaccine, developed in partnership with the University of Oxford, was designed to be the workhorse of the global vaccination effort, with some two billion doses ordered for use in more than 70 countries this year.

The European Union’s vaccination efforts have been hindered by political infighting, a supply shortage and a lack of solidarity. And with many countries heavily reliant on the AstraZeneca vaccine, the decision by some to suspend its use while the bloc’s regulatory body looks into safety concerns will slow things down even more.

“AstraZeneca is a very substantial part of the European investment,” said Dr. Don Goldmann, a professor of epidemiology at Harvard’s T.H. Chan School of Public Health. “It is going to be delayed and much harder to have enough of the alternative vaccines to have a coordinated rapid response.”

Clotting problems are relatively common in the general population, and health authorities suspect that the small number of cases reported in vaccine recipients are most likely coincidental.

The French prime minister said on Tuesday that he would “very quickly” get a shot of the AstraZeneca vaccine if France lifts its suspension, in a bid to reassure the French population that it was safe.

Camilla, the Duchess of Cornwall, said on a visit to a vaccination center in London on Tuesday that she had received the AstraZeneca vaccine, Reuters reported.

While the AstraZeneca vaccine is already authorized in dozens of countries, it has not yet been approved by U.S. regulators. The results from its clinical trial in the United States have not yet been reported, and the company has not sought emergency use authorization from the Food and Drug Administration.

Prime Minister Prayuth Chan-ocha of Thailand received his first shot of the AstraZeneca vaccine in Bangkok on Tuesday.
Thai Government, via EPA

While some countries have suspended the use of AstraZeneca’s coronavirus vaccine over safety concerns, Thailand on Tuesday kicked off a program for its distribution nationwide, with Prime Minister Prayuth Chan-ocha receiving the first shot.

Thailand is one of several countries, including Australia and India, that are continuing to use the AstraZeneca vaccine as experts investigate reports of fatal brain hemorrhages and blood clots among a handful of people who received it. Millions of people around the world have been inoculated with the AstraZeneca vaccine, and scientists say there is no evidence that it causes blood clots, which can occur for any number of reasons.

More than a dozen countries, mostly in Europe, have paused AstraZeneca vaccinations in the last few days, raising fears that vaccinations will be disrupted at a critical time. In Asia, Indonesia also said on Monday that it would not start distributing the AstraZeneca vaccine until it could determine that it was safe.

The AstraZeneca vaccine, which has been authorized in more than 70 countries, is seen as key to fighting the virus in the developing world because it is cheaper and easier to store than other vaccines.

Thailand on Friday became the first country outside Europe to delay use of the AstraZeneca vaccine, which Mr. Prayuth had been scheduled to receive that day. By Monday, however, officials said they had received information from the World Health Organization and the European Medicines Agency confirming that the vaccine was not connected to the occurrence of blood clots and was safe to use.

In an event on Tuesday that was broadcast online, Mr. Prayuth, 66, selected a vial from a box of AstraZeneca vaccines, inspected the label and received his shot as officials around him applauded.

“I feel good,” he said moments later. “This will build confidence for the general public in the government vaccination program.”

AstraZeneca is one of two vaccines authorized for use in Thailand, with the Thai company Siam Bioscience expected to produce 61 million doses by the end of the year.

Other countries agree that there is insufficient evidence to justify suspension. In a statement on Tuesday, the Australian medicines regulator said it had not received any reports of blood clots among people who had received the AstraZeneca vaccine. Greg Hunt, the health minister, also said the government supported continued use of the shot.

“There have been views expressed — we disagree with them clearly, absolutely, unequivocally,” he said in Parliament.

AstraZeneca is central to Australia’s vaccination drive, with most of the 53.8 million doses the government has secured being manufactured domestically.

Officials in India, where the AstraZeneca vaccine is manufactured locally and known as Covishield, have said there is no immediate concern. They are reviewing data on adverse effects for the AstraZeneca vaccine and for the other shot being used, a domestic vaccine called Covaxin.

Education staff at Kettering City Schools received the Covid-19 vaccine in Dayton, Ohio, last month.
Megan Jelinger/Agence France-Presse — Getty Images

Ohio and Indiana are the latest states to announce significant expansions in Covid-19 vaccine eligibility for their residents, joining other states that have been broadening the criteria for who can get vaccinated weeks ahead of the May 1 deadline set by President Biden to open vaccine eligibility to all adults in the country.

In Ohio, eligibility will be extended to anyone 40 years and older as of Friday, as well as for residents with certain medical conditions. Indiana extended its group of eligible residents to people 45 and older, effective immediately. And Wisconsin on Tuesday said residents 16 years and older with certain medical conditions will be eligible for vaccinations a week earlier than initially planned.

Since vaccinations began in December, the federal government has delivered nearly 143 million vaccine doses to states and territories, of which more than 77 percent have been administered, according to data maintained by the Centers for Disease Control and Prevention. And the White House on Tuesday said it was sending another 22 million doses this week in total to states and other jurisdictions as well as pharmacies and community health centers. Recently, the United States has averaged about 2.4 million shots a day.

The country first prioritized the distribution of vaccines for the most vulnerable members of the population, including health workers, nursing home residents and people 65 years and older.

As of Monday, nearly 65 percent of the country’s older population have received at least one dose of the vaccine, according to C.D.C. data, with 36 percent fully vaccinated.

In addition to calling on states to offer vaccines to all adults by May 1, Mr. Biden has said that the United States will have secured enough doses by the end of May for shots to be made available to them. And several states across the country have already begun expanding the criteria for vaccinations.


50+ or 55+

60+ or 65+

Eligible only in some counties


Restaurant workers

Eligible only in some counties


High-risk adults

Over a certain age

Eligible only in some counties

In Indiana, where new coronavirus cases, hospitalizations and deaths have decreased, 20 percent of the population has had at least one dose, and 11 percent is fully vaccinated, according to a New York Times analysis of data from the C.D.C.

The pace of vaccinations in both Indiana and Ohio is commensurate to the national pace of vaccinations, according to a Times database.

In Ohio, as of Monday, about 21 percent of adults in the state had received at least one shot and 12 percent were totally vaccinated, according to a Times database.

Gov. Mike DeWine of Ohio, a Republican, announced the expanded eligibility on Tuesday, as well as a goal of working up to administering 6,000 shots a day across the state in the coming days, an increase over the 1,500 shots a day he said the state is currently administering. Ohio will make vaccines eligible to all Ohio residents 16 years and older on March 29.

With the expanded criteria, Mr. DeWine said another 1.5 million Ohio residents will be eligible for the vaccine on Friday. He also said a new Federal Emergency Management Agency mass vaccination site, the Cleveland State University’s Wolstein Center, would handle shots for more than 200,000 people over the next eight weeks.

Putting a mass vaccination site on Cleveland State’s campus, Mr. DeWine said, was a deliberate move, given its proximity to some underserved neighborhoods. Mr. DeWine said free transportation to and from the Wolstein Center would be provided. He added that he and Mr. Biden have made equity a priority in vaccine distribution plans, a concern that is shared by officials across the country who worry about fully understanding the extent of the problem because of missing data on race and ethnicity.

In early March, less than 5 percent of Ohio’s Hispanic population and less than 10 percent of the state’s Black population had been vaccinated, according to a Times analysis. Communities of color across the country have been among the hardest hit by the pandemic and have faced obstacles to accessing vaccines, in some cases because of a lack of reliable internet access, as well as inflexible work schedules. In early March, the vaccination rate for Black people across the country was half of the rate for white people.

“I want to thank the president, President Biden, for making this site available to us,” Mr. DeWine said during a news conference on Tuesday.

Despite the praise from Mr. DeWine, Mr. Biden continues to face vaccine resistance from some Republicans across the country. A third of Republicans who participated in a recent CBS News poll said that they would not be vaccinated. And another 20 percent of Republicans said they were unsure.

The opposition could extend the time it takes for the country to return to normal activities, with economic, health and social consequences — developments that members of both political parties favor.

People wait for a movie to start in Burbank, Calif. L.A. County allowed theaters, restaurants and gyms to reopen on Monday as Covid-19 cases continue to decline.
Philip Cheung for The New York Times

This week, California is taking its biggest steps yet toward a full reopening, a year after the state became the first in the nation to impose a shelter-in-place order.

For the first time in months, restaurants up and down most of California, including in Los Angeles, Sacramento, San Diego and Orange counties, are allowed to open indoor dining rooms. Gyms, movie theaters and other businesses have also gotten the green light to operate inside at reduced capacity, as most of the state’s 58 counties are allowed to move to less restrictive tiers in the state’s color-coded reopening framework.

“And we’re going to see even more movement next week,” Gov. Gavin Newsom said on Tuesday, speaking from an Alameda County elementary school. “We’re going to see more and more business activity, more people back in schools, more energy, more optimism about our state and its future.”

Mr. Newsom highlighted the state’s relatively low rate of positive Covid-19 tests, and how far the numbers have dropped over the past eight weeks, since the state emerged from its deadliest surge.

He emphasized that even as the state continues to grapple with confusion over its vaccine rollout, “the only constraint is supply,” and said officials were working to be able to make vaccines available to any adult by May 1, as President Biden has directed.

“Our North Star continues to be equity,” he said. “It’s probably the hardest thing we’re doing.”

Still, Mr. Newsom noted that more than 12 million doses of the vaccine had been administered already, more than most countries and the most of any state.

The governor’s upbeat assessment came as he faces intense pressure to reopen even more quickly, particularly from supporters of an effort to oust him from office.

Earlier on Tuesday, in a virtual news conference, a group of state lawmakers and county leaders called on the governor to lift all statewide restrictions and instead allow local officials to make their own decisions about precautions.

Don Wagner, an Orange County supervisor who has been a vocal critic of the governor and the state’s health orders, said that Mr. Newsom’s approach hasn’t been effective.

“We’re now one year on from the governor’s initial orders,” he said. “Early on, the governor got a pass — we didn’t criticize him. It was a novel virus.”

But as more information about the coronavirus emerged, and businesses continued to suffer, Mr. Wagner said the governor should have “let the legislature make the laws.”

Protesters against masks, vaccines and vaccine passports gather outside the headquarters of the Centers for Disease Control (CDC) on Saturday in Atlanta, Georgia.
Elijah Nouvelage/Getty Images

Former President Donald J. Trump, in a nationally televised interview, recommended the Covid-19 vaccine to Americans who were reluctant to get it, including his supporters.

Mr. Trump and his wife, Melania, were vaccinated in secret in January. Vaccine proponents have been calling on him to speak more forcefully in favor of the shots to his legions of supporters, many of whom remain reluctant, polls show.

Speaking to Maria Bartiromo on “Fox News Primetime” on Tuesday evening, Mr. Trump said, “I would recommend it, and I would recommend it to a lot of people that don’t want to get it, and a lot of those people voted for me frankly.”

He added: “It is a safe vaccine, and it is something that works.”

While there are degrees of opposition to vaccination for the coronavirus among a number of groups, including African-Americans and antivaccine activists, polling suggests that opinions are breaking substantially along partisan lines.

A third of Republicans said in a CBS News poll that they would not be vaccinated — compared with 10 percent of Democrats — and another 20 percent of Republicans said they were unsure. Other polls have found similar trends.

Mr. Trump encouraged attendees at the Conservative Political Action Conference in Orlando, Fla., late last month to get vaccinated.

Still, Mr. Trump — whose tenure during the pandemic was often marked by railing against recommendations from medical experts — said on Tuesday that “we have our freedoms and we have to live by that, and I agree with that also.”

With President Biden’s administration readying television and internet advertising and other efforts to promote vaccination, the challenge for the White House is complicated by perceptions of Mr. Trump’s stance on the vaccine.

Asked about the issue on Monday at the White House, Mr. Biden said Mr. Trump’s help promoting vaccination was less important than getting trusted community figures on board.

“I discussed it with my team, and they say the thing that has more impact than anything Trump would say to the MAGA folks is what the local doctor, what the local preachers, what the local people in the community say,” Mr. Biden said, referring to Mr. Trump’s supporters and campaign slogan “Make America Great Again.” Until everyone is vaccinated, Mr. Biden added, Americans should continue to wear masks.

Widespread opposition to vaccination, if not overcome, could slow the United States from reaching the point where the virus can no longer spread easily, setting back efforts to get the economy humming again and people back to a more normal life. While the problem until now has been access to relatively tight supplies of the vaccine, administration officials expect to soon face the possibility of supply exceeding demand if many Americans remain reluctant.

“The national atmosphere around vaccine uptake matters,” said John Bridgeland, the founder and chief executive of Covid Collaborative, a bipartisan group working closely with the White House on issues of vaccine hesitancy. “Although the ground game is the most important thing, having a tail wind behind us at the national level with every single living President and first lady, regardless of party, saying Americans should get this safe and effective vaccine creates the kind of tail winds we are looking for.”

Annie Karni contributed reporting.

A vaccination center in Beijing last month.
EPA, via Shutterstock

China has approved its fifth Covid-19 vaccine, and it’s made from the ovary cells of hamsters.

The vaccine was developed by Anhui Zhifei Longcom Biopharmaceutical Co. and the Chinese Academy of Sciences. It was developed by a team led by George Gao, the head of the Chinese Center for Disease Control and Prevention.

The Chinese Academy of Sciences said in a statement on Tuesday that the Chinese government had given the shot authorization for emergency use on March 10. This is the fourth vaccine China has approved for emergency use after two vaccines made by Sinopharm, a state-owned vaccine maker, and one developed by Sinovac, a private Beijing company. It has also approved a fifth vaccine, made by the Chinese company CanSino Biologics in partnership with the military, for general use.

Neither the company nor the institute behind the latest vaccine to be approved has published efficacy data from its Phase 3 trials, which are taking place in China, Ecuador, Indonesia, Pakistan and Uzbekistan.

Uzbekistan has approved the vaccine. The Chinese Academy of Sciences said that Phase 3 clinical trials, which involve 29,000 volunteers, were “progressing smoothly.”

In Phase 1 and 2 trials in China, the Chinese Academy of Sciences said, there were no serious adverse reactions among the volunteers and the vaccine produced neutralizing antibodies at levels on par with those of other coronavirus shots. Those results have not been peer-reviewed.

The process of manufacturing the vaccine begins when the genetic code for the coronavirus spike protein is placed into the ovary cells of hamsters, commonly the subjects of medical research.

The cells start to make the protein, and once they reach a sizable volume they are harvested and purified. The vaccine is completed with an adjuvant, an ingredient that shores up the immune system.

The Chinese Academy of Sciences said that production of the vaccine could be easily scaled up in China and elsewhere, and that it would be convenient for storage and transportation.

But the vaccine has several drawbacks. One is that it does not produce many T-cells, which help clear infected cells and prevent them from spreading.

Without these cells, a person’s antibody levels may not be high enough to clear the infection, said Ooi Eng Eong, a professor of microbiology and immunology at the National University of Singapore. “You are more likely to get a breakthrough infection,” he said.

Elsie Chen contributed research.

GLOBAL ROUNDUP

Lining up as the police escorted a hearse carrying the coffin of Papua New Guinea’s first prime minister, Michael Somare, in Port Moresby on Thursday.
Andrew Kutan/Agence France-Presse — Getty Images

Papua New Guinea, which had largely avoided the coronavirus, is now sounding the alarm over an outbreak that its prime minister said could infect up to a third of the country’s population.

The small island nation has recorded 2,269 coronavirus cases and 26 deaths since the beginning of the pandemic, according to the country’s health department. Nearly half of the infections were recorded in the last two weeks, and 97 cases were reported on Sunday.

On Monday, Prime Minister James Marape called the situation “critical” and said that restrictions on movement would be brought in. The nation’s businesses will be allowed to remain open, but residents will not be allowed to leave their provinces or villages.

Only about 55,000 of the nation’s nine million people have been tested for the coronavirus, a low rate that signals the actual number of infections may be much higher than reported.

There are also concerns that the country’s fragile health system will buckle under the strain, and that recently held gatherings to commemorate former Prime Minister Michael Somare, who died last month, would become super-spreader events.

The spike in cases has prompted concerns in neighboring Australia that the outbreak could spread to its shores. The Torres Strait Islands, an autonomously administered group of islands, are just two and a half miles from Papua New Guinea at the nearest point.

Aid groups and Australia’s opposition party have urged the government to provide emergency vaccine doses to Papua New Guinea. The smaller nation has sourced 200,000 doses of the AstraZeneca vaccine from Australia and 70,000 from India, but is not expected to get its first vaccine doses until at least next month.

In other developments across the world:

  • Prime Minister Boris Johnson of Britain on Tuesday defended the safety and efficacy of the AstraZeneca vaccine, which was produced with the University of Oxford. “That vaccine is safe and works extremely well,” he said in The Times of London, arguing that the nation’s inoculation campaign would bear fruits only if other countries had successful vaccine rollouts. “Successful as the U.K. vaccination program may be, there is little point in achieving some isolated national immunity.”

  • In France, the authorities identified a new variant of the coronavirus that does not appear to be deadlier or more contagious than other variants but that could be harder to detect with traditional testing. Eight cases of the variant were identified in a cluster of infections at a hospital in the western region of Brittany. Local health authorities said the variant was not “worrying” but would be closely monitored. Some of the people infected with the new variant cases had tested negative with a PCR nose swab, even though they had symptoms and more thorough testing showed that they had Covid-19.

  • Officials in France acknowledged that temporarily suspending use of the AstraZeneca vaccine would slow down the country’s vaccination campaign, but said that caution was necessary. Alain Fischer, an immunologist who heads the government’s vaccination advisory council, told France Inter radio on Tuesday that the suspension was a “hard blow” but that it was “reasonable to be cautious.”

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Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, discussed the findings of a new study that suggests three feet, not six feet, was sufficient distance for students if they adhere to safety precautions.Ben Garver/The Berkshire Eagle, via Associated Press

The Centers for Disease Control and Prevention is clear in its social distancing recommendation: To reduce the risk of contracting the coronavirus, people should remain at least six feet away from others who are not in their households.

The guideline has been especially consequential for schools, many of which have not fully reopened because they do not have enough space to keep students six feet apart.

Now, spurred by a better understanding of how the virus spreads and a growing concern about the harms of keeping children out of school, some public health experts are calling on the agency to reduce the recommended distance in schools from six feet to three.

“It never struck me that six feet was particularly sensical in the context of mitigation,” said Dr. Ashish Jha, dean of the Brown University School of Public Health. “I wish the C.D.C. would just come out and say this is not a major issue.”

On Sunday, Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, said on CNN that the C.D.C. wasreviewing the matter.

A member of the United States military at trailer-style housing for legal staff at Guantánamo Bay, Cuba, in 2019.
Doug Mills/The New York Times

More than two months into a campaign to give shots to troops and other essential residents at Guantánamo Bay, about one-third of the people who live at the remote naval station in Cuba have been fully vaccinated, according to Department of Defense figures.

The Pentagon has declined to say how many eligible troops and other residents at the outpost have declined the vaccine, or how many have received one dose but are not yet fully vaccinated. None of the wartime prisoners at the base have been vaccinated.

Guantánamo functions in some respects like a small town, with a K-12 school, church, community hospital and suburban-style neighborhoods for the families of Navy personnel and Pentagon contractors. There are about 5,100 adults residing at the base, including the 1,500 troops who serve at the prison on nine-month tours of duty, as well as about 400 children.

The military began vaccinating residents on Jan. 8 with the Moderna vaccine, starting with military medical personnel assigned to the prison and the hospital at the base. By Feb. 2, everyone who works at the prison, in or out of uniform, had been offered the vaccine, a prison spokesman said last month. Eligibility has been expanded to include hundreds of others, from commissary and airport workers to Navy officers and workers assigned to the war crimes court at the base, which has been closed through nearly the whole pandemic.

Lt. Col. Kenneth L. Hoffman of the Air Force, a Pentagon spokesman, said on Tuesday that as of March 12, a total of 3,200 people at the base were eligible, and 58 percent of them had been fully vaccinated — equivalent to about one-third of the base’s total population.

Spot testing, a 14-day quarantine for new arrivals and other measures have managed to prevent the virus from spreading at the isolated base. But the military cannot require troops to get a Covid vaccine, as it can with other immunizations, because the Covid shots are being given under an emergency use authorization.

Across the military, roughly one-third of active duty or National Guard troops have said no to the vaccines, particularly younger troops. The Pentagon has declined to describe the extent of refusals at Guantánamo.

The issue of vaccinating the 40 wartime prisoners held at Guantánamo has stirred some controversy. A Pentagon health official decided on Jan. 27 that the prisoners should be offered vaccination once all the troops at the base who wanted to be inoculated had a first dose. But the idea was put on hold after a public and political outcry, and there is currently no plan to vaccinate the prisoners, who range in age from the 30s to 73.

The coronavirus has been a major obstacle to resuming pretrial hearings in the prosecution related to the Sept. 11 terror attacks, in part because almost everyone involved other than the defendants travels to the court from across the United States.

Three prisoners charged with links to a terror cell in Southeast Asia were due for court appearances in February, their first in 17 years of detention, but an Army judge postponed the hearing until the summer, citing a lack of vaccinations and the risk of traveling during the pandemic.

The Delacorte Theater in Central Park on Sunday. The Public Theater said it would resume Shakespeare in the Park in July with one production for eight weeks.
George Etheredge for The New York Times

The path back for performing arts in America is winding through a parking lot in Los Angeles, a Formula 1 racetrack in Texas, and Central Park in New York.

On Tuesday, New York City’s Public Theater said that it would seek to present Shakespeare in the Park once again this summer, restarting a cherished city tradition that last year was thwarted for the first time in its history.

“This is one of the great ways that the theater can make a celebration,” said Oskar Eustis, the theater’s artistic director, who is among the 29 million Americans who have been infected with the coronavirus.

This is not business as usual and hurdles remain. But the signs of life are indisputable.

In Los Angeles, the Fountain Theater is about to start building a stage in the East Hollywood parking lot where it hopes in June to open that city’s first production of “An Octoroon,” an acclaimed comedic play about race by Branden Jacobs-Jenkins. Austin Opera next month aims to perform outdoors for the first time, staging “Tosca” in an amphitheater at a Formula 1 racetrack, while in upstate New York, the Glimmerglass Festival is planning to erect a stage on its lawn.

Mark Volpe, the president and chief executive of the Boston Symphony Orchestra, said that he soon plans to ask his board to approve a plan to hold performances this summer at Tanglewood, the company’s outdoor campus in Western Massachusetts.

There are other big examples: Lincoln Center, the vast New York nonprofit, has announced that it will create 10 outdoor spaces for performance on its plaza, starting next month, while the Brooklyn Academy of Music and Playwrights Horizons are planning to stage Harris’s play, “What to Send Up When It Goes Down,” in June in the Brooklyn Botanic Garden.

And on Monday, the Los Angeles Philharmonic Association said it anticipates limited-capacity live performances at the Hollywood Bowl this summer.

Pedestrians walking past an N.C.A.A. banner in Indianapolis on Sunday.
Lee Klafczynski for The New York Times

The N.C.A.A. quietly rewrote part of its coronavirus safety protocols, which college sports administrators have routinely used to justify holding basketball championships during the pandemic, to potentially shorten the quarantines of some teams arriving in Indiana for the Division I men’s tournament.

The association’s published health guidelines, which also apply to the women’s tournament scheduled to begin next week in Texas, call for teams to “remain in quarantine until two consecutive tests on separate days are confirmed negative, at which time team practice may begin.” But the N.C.A.A.’s unannounced change offers teams arriving late at night a quicker way out: negative results on virus tests separated by at least 12 hours.

The shift, acknowledged only after inquiries from The New York Times, allowed Iona, the No. 15 seed in the East region, to practice less than 24 hours after its chartered plane landed in Indianapolis late in the night it clinched its automatic bid.

The episode involving Iona, which Coach Rick Pitino steered to a victory in the Metro Atlantic Athletic Conference tournament on Saturday, is an early signal of how the N.C.A.A. may interpret, apply and change the safety rules it is relying on to stage 67 games in Indiana over the coming weeks.

Like their counterparts in many leagues, college sports administrators routinely recalibrated their approach to the pandemic, not just in details but sometimes with respect to issues they had depicted as foundational principles. Last year, for instance, executives regularly said that college games would not happen unless students were on campuses for classes — a position that ultimately faded away as the fall football season approached.

Waiting to receive the Sinovac vaccine in Hong Kong last month.
Isaac Lawrence/Agence France-Presse — Getty Images

Chinese embassies in a rapidly growing number of countries, including the United States, have begun requiring that foreigners entering China must first be fully inoculated with a Chinese-made coronavirus vaccine if they want to avoid extensive paperwork requirements.

Complying with the rule will be difficult for people applying for Chinese visas in places that are not offering vaccines produced in China. No Chinese-made vaccine has been approved in the United States or most of Europe.

Many regulators outside China have been wary of vaccines made by companies in China, notably Sinovac and Sinopharm. The companies have released relatively little data from Phase 3 trials to allow independent assessments of the vaccines’ efficacy and safety.

The Chinese Foreign Ministry announced similar rules for foreigners wanting to enter the Chinese mainland from Hong Kong. It said on Saturday that if they received a Chinese-made vaccine they would not need to meet other requirements, including a negative nucleic acid test, detailed health and travel records, and a personal invitation from a Chinese provincial government agency.

Some foreigners who live and work in the Chinese mainland but left early in the pandemic have been living in limbo for a year or more in Hong Kong, which has authorized the Sinovac and BioNTech vaccines, and elsewhere.

By Tuesday morning, Chinese embassies had issued identical rules in Britain, Japan, Norway, Pakistan, the Philippines, Thailand, the United States, Vietnam and at least a dozen other countries.

The Chinese stance puts pressure on other countries to give regulatory approval to China’s vaccines. Beijing has not allowed vaccines developed in other countries to be produced or administered in China.

Thousands of businesspeople and students have been seeking visas to resume their work or studies in China. The country’s borders have been among the most tightly closed in the world to prevent the coronavirus from re-entering the country after being largely stamped out. Business leaders say the new vaccine recommendation adds to the hurdles.