In an early analysis of coronavirus vaccine safety data, researchers at the Centers for Disease Control and Prevention have found no evidence that the Pfizer-BioNTech or Moderna vaccines pose serious risks during pregnancy.

The findings are preliminary and cover just the first 11 weeks of the U.S. vaccination program. But the study, which included self-reported data on more than 35,000 people who received one of the vaccines during or shortly before pregnancy, is the largest yet on the safety of the coronavirus vaccines in pregnant people.

During the clinical trials of the vaccines, pregnant women were excluded. That left patients, doctors and experts unsure whether the shots were safe to administer during pregnancy.

“There’s a lot of anxiety about whether it’s safe and whether it would work and what to expect as far as side effects,” said Dr. Stephanie Gaw, a maternal-fetal medicine specialist at the University of California, San Francisco.

The new data, Dr. Gaw said, demonstrate that “a lot of pregnant people are getting the vaccine, there isn’t a significant increase in adverse pregnancy effects at this point, and that side effect profiles are very similar to nonpregnant people.”

“I think that’s all very reassuring,” she said, “and I think it will really help providers and public health officials more strongly recommend getting the vaccine in pregnancy.”

Covid-19 poses serious risks during pregnancy. Pregnant women who develop symptoms of the disease are more likely to become seriously ill, and more likely to die, than nonpregnant women with symptoms.

Because of those risks, the C.D.C. has recommended that coronavirus vaccines be made available to pregnant women, though it also suggests that they consult with their doctors when making a decision about vaccination.

The new study, which was published on Wednesday in The New England Journal of Medicine, is based largely on self-reported data from V-safe, the C.D.C.’s coronavirus vaccine safety monitoring system. Participants in the program use a smartphone app to complete regular surveys about their health, and any side effects they might be experiencing, after receiving a Covid-19 vaccine.

The researchers analyzed the side effects reported by V-safe participants who received either the Pfizer or Moderna vaccine between Dec. 14, 2020, and Feb. 28, 2021. They focused on 35,691 participants who said that they had been pregnant when they received the vaccine or became pregnant shortly thereafter.

After vaccination, pregnant participants reported the same general pattern of side effects that nonpregnant ones did, the researchers found: pain at the injection site, fatigue, headaches and muscle pain.

Women who were pregnant were slightly more likely to report injection site pain than women who were not, but less likely to report the other side effects. They were also slightly more likely to report nausea or vomiting after the second dose.

Pregnant V-safe participants were also given an opportunity to enroll in a special registry that tracked pregnancy and infant outcomes.

By the end of February, 827 of those enrolled in the pregnancy registry had completed their pregnancies, 86 percent of which resulted in a live birth. Rates of miscarriage, prematurity, low birth weight and birth defects were consistent with those reported in pregnant women before the pandemic, the researchers report.

“This study is of critical importance to pregnant individuals,” Dr. Michal Elovitz, a maternal-fetal medicine specialist at the University of Pennsylvania, said in an email. “It is very reassuring that there were no reported acute events in pregnant individuals” over the course of the study, she said.

But the report has several limitations and much more research is needed, experts said. Enrollment in the surveillance programs is voluntary and the data are self-reported.

In addition, because the study period encompassed just the first few months of the U.S. vaccination campaign, the vast majority of those enrolled in the pregnancy registry were health care workers. And there is not yet any data on pregnancy outcomes from people who were vaccinated during the first trimester of pregnancy.

“I think we can feel more confident about recommending the vaccine in pregnancy, and especially with pregnant people that are at risk of Covid,” Dr. Gaw said. “But we do need to wait for more data for complete pregnancy outcomes from vaccines early in pregnancy.”

WASHINGTON — Federal regulators have found serious flaws at the Baltimore plant that had to throw out up to 15 million possibly contaminated doses of Johnson & Johnson’s coronavirus vaccine, casting doubt on further production in the United States of a vaccine that the government once viewed as essential in fighting the pandemic.

The regulators for the Food and Drug Administration said that the company manufacturing the vaccine, Emergent BioSolutions, may have contaminated additional doses at the plant. They said the company failed to fully investigate the contamination, while also finding fault with the plant’s disinfection practices, size and design, handling of raw materials and training of workers.

The F.D.A. has not yet certified the plant, in Baltimore’s Bayview neighborhood, and no doses made there have gone to the public. All the Johnson & Johnson shots that have been administered in the United States have come from overseas.

The report amounted to a harsh rebuke of Emergent, which had long played down setbacks at the factory, and added to problems for Johnson & Johnson, whose vaccine had been seen as a game changer because it requires only one shot, can be produced in mass volume and is easily stored.

The inspection began after routine checks showed that Emergent workers had contaminated at least part of a batch of 13 million to 15 million doses of the Johnson & Johnson vaccine with the harmless virus that is used to make the AstraZeneca shot, which is not yet authorized in the United States.

The F.D.A. findings, based on an inspection that ended on Tuesday, underscore questions raised in reports by The New York Times about why Emergent did not fix problems earlier and why federal officials who oversee its lucrative contracts did not demand better performance.

In statements on Wednesday, the F.D.A., Emergent and Johnson & Johnson all said they were working to resolve the problems at the factory. There was no indication of how long that would take.

Global Roundup

BERLIN — State lawmakers in Germany approved a new version of a law on Thursday boosting the federal government’s power to enforce uniform coronavirus lockdown rules. New restrictions are expected in most districts soon after the president signs the bill into law, which could be as early as Thursday afternoon.

The law, which Chancellor Angela Merkel’s cabinet passed last week, is a response to a disjointed virus response by state governments, which previously had the ultimate say in carrying out restrictions. For months, experts have called for a lockdown to control Germany’s surging third wave of coronavirus infections.

Under the law passed by the federal council of states on Thursday, the rules would apply uniformly across the country but would depend on the rate of infection in each district, leading to more severe lockdowns in highly affected areas. There would be a curfew from 10 p.m. to 5 a.m. in districts with more than 100 new infections per 100,000 people in a week. Restaurants would remain closed, and nonessential stores would require an appointment and a negative test result in districts with more than 150 new infections per 100,000 people. Schools would close if 165 new infections per 100,000 were registered.

Germany is currently measuring 161 infections per 100,000 in a week, according to the health authorities, which also counted 29,518 new infections on Wednesday.

As many as 8,000 people, including right-wing extremists and coronavirus deniers, took to the streets in Berlin to protest the measures on Wednesday. Several lawsuits against it have already been announced.

Germany has recorded more than 80,000 deaths so far.

In other developments across the world:

• Japan’s auto industry group canceled the biennial Tokyo Motor Show, scheduled for the fall, because of rising coronavirus cases, the Kyodo News agency reported. It was the first cancellation in the 67-year history of the event, which drew around 1.3 million people in 2019. Akio Toyoda, the chairman of the industry group and president of Toyota Motor Corp., said at a news conference that “it seems difficult to offer main programs in a safe environment.” The cancellation came as Japan reported 5,291 new infections, the highest daily total in three months. And it raised more questions about plans for the Tokyo Olympics, which organizers have insisted will begin in July even as officials plan to impose emergency measures in Tokyo and other municipalities.

• The European Union will not order an extra 100 million vaccines from AstraZeneca foreseen in its contract, a European Commission spokesman said Thursday, underscoring the soured relationship between the pharmaceutical company and the bloc of 27 countries. The bloc could have added 100 million doses of vaccines to its existing order of 300 million from AstraZeneca but the time to do so has passed, Stefan de Keersmaecker, the spokesman, said. The European Union is embroiled in a dispute with the British-Swedish company over its inability to deliver expected doses, which has set the bloc’s vaccination efforts back significantly. They have been in a legal arbitration process for weeks, and the bloc is considering suing.

KATHMANDU, Nepal — At the beginning of this month, Nepal’s dethroned king, Gyanendra Shah, and his wife, Komal, traveled to northern India for the Kumbh Mela, a Hindu pilgrimage where millions seek a dip in the Ganges River to absolve themselves of their sins.

Gyanendra bathed in the river, and for 10 days, he and his aides mingled in crowds and met ascetics, Hindu leaders and other dignitaries. On April 18, he and Komal flew home to Nepal, where supporters welcomed them at the airport and formed a procession to escort them home, chanting pro-Hindu and pro-monarchy slogans along the way.

Three days later, the couple tested positive for the coronavirus. Now they are in quarantine at their residence in Kathmandu, the capital, while health officials in Nepal try to trace anyone who was in contact with them.

“Both king and queen have isolated themselves from other family members,” said Phani Raj Pathak, an aide to Gyanendra, who was dethroned when Nepal became a republic in 2008 and ended a two-century-old Hindu monarchy. The former ruler, who is in his 70s, retains support among some Hindus in Nepal as well as among critics of the elected government.

The infections have cast a harsh spotlight on the Kumbh Mela, where millions of Hindu pilgrims have gathered for weeks, shoulder to shoulder and often maskless, even as highly infectious variants of the coronavirus surge across South Asia. On Thursday, India reported more than 312,000 new infections, the highest daily total in any country since the pandemic began.

The Indian government has defended the gathering as safe, even as news media report thousands of infections among participants. Organizers say that attendees are required to wear masks and show proof of a negative coronavirus test, but they acknowledge that given the size of the event, many could have flouted the rules.

Now there are fears that the Kumbh Mela will cause the virus to explode in Nepal, which shares a porous border with India.

“The majority of people weren’t wearing face masks,” said Yogini Saritanandi, a pilgrim who returned to Nepal. She said she had seen “nothing other than a sea of humans on the bank of the Ganges.”

She said the authorities in the northern city of Haridwar, where the Kumbh Mela is being observed this year, began to slightly restrict entry after a few ascetics were reportedly infected and after India’s prime minister, Narendra Modi, urged organizers to observe social distancing. But it appeared to be too late.

“People got Covid one after another,” said Ms. Saritanandi, 43. “When I saw this, I thought of my 10-year-old son, and I cut my visit short to return to Nepal earlier.”

As Indian states impose new lockdowns, tens of thousands of Nepali migrant workers have returned from India without undergoing coronavirus tests. After reporting no new infections for much of January, Nepal is now averaging more than 1,100 cases a day, according to a New York Times database.

The government has closed schools and colleges in urban areas and tried to speed up vaccinations, with more than 1.7 million people having received at least one shot. But the inoculation drive was slowed after India restricted exports of vaccines to fight the outbreak at home, leaving Nepal to rely on a donation of shots from China.

Fully vaccinated baseball fans will be granted their own section at the Los Angeles Dodgers game this weekend against the San Diego Padres.

The set-aside seats, reported by The Los Angeles Times, are part of the many incentives being offered — from doughnuts to beer — to encourage people to get vaccinated against Covid-19. The Miami Heat and the San Francisco Giants have introduced similar sections at their stadiums.

To prove they are fully vaccinated, fans will have to show government-issued I.D. and documentation like a vaccination card, according to the Dodgers’ website. Everyone 16 years and older will have to show proof that at least two weeks have passed since they were fully vaccinated. Fans younger than 16 will be required to show proof of a negative coronavirus test taken within 72 hours before admission.

Face masks will still be required, but social distancing will not. The team said spectators in the sections for the fully vaccinated will be seated directly next to each other.

The game Saturday won’t mark the first time fans have entered Dodger Stadium since the pandemic began. The team’s home opener on April 9 was attended by fans — just not all that many of them. Attendance was capped at around 11,000, about 20 percent of capacity.

In the past week, there has been an average of more than 2,300 daily coronavirus cases in the state, and Los Angeles County has seen an average of 435 daily cases — a 20 percent drop over the past two weeks, according to a New York Times database.

As of Wednesday, more than 40 percent of Californians had received at least one dose of the vaccine, and more than 20 percent had been fully vaccinated.

On April 15, Gov. Gavin Newsom loosened some restrictions in the state, permitting limited outdoor gatherings and live events, depending on a region’s Covid-19 risk level.

New York Road Runners, the club that puts on the New York City Marathon, has announced the return of its first regularly scheduled race since the beginning of the pandemic.

On Thursday, the club said that it would hold the annual New York Mini 10K on June 12. The 10-kilometer, women-only race has been held annually since 1972, with the exception of last year.

“This is our first real table setting,” said Kerin Hempel, the organization’s interim chief executive. “It’s starting to feel like ‘OK, we’re back, we’re coming back.’”

This will not be the first race the club has held since the onset of the pandemic.

The organization has held a series of “return to racing” events as pilots starting last fall, allowing very small fields to run with safety protocols in place. Among other measures, the races had temperature checks, staggered starts and different corralling of runners.

Those events, Ms. Hempel said, have given N.Y.R.R. the confidence to move ahead with its first regularly scheduled race since March 2020.

The Mini 10K field will be smaller than in past years, with a cap of 1,200 runners. The race will also have safety protocols, such as requiring runners to mask up at the start and finish. (They will be strongly encouraged to wear masks during the race, too.)

It will be the first time N.Y.R.R. has welcomed elite athletes since the 2019 New York City Marathon, with 25 elite athletes expected at the starting line. The 2019 Mini 10K champion, Sara Hall, will return to defend her title.

The announcement comes as runners look ahead — with cautious optimism — to the return of major road races. Ms. Hempel anticipated the question on the minds of many: What does this mean for the New York City Marathon?

“We’ve been saying the marathon is going to happen,” she said. “It’s more about what it’s going to look like, and how many people we can accommodate on the course.”