A monoclonal antibody cocktail developed by the drug maker Regeneron offered strong protection against Covid-19 when given to people living with someone infected with the coronavirus, according to clinical trial results announced on Monday. The drug, if authorized, could offer another line of defense against the disease for people who are not protected by vaccination.
The findings are the latest evidence that such lab-made drugs not only prevent the worst outcomes of the disease when given early enough, but also help prevent people from getting sick in the first place.
Using the cumbersome drugs preventively on a large scale won’t be necessary: Vaccines are sufficient for the vast majority of people and are increasingly available.
Still, antibody drugs like Regeneron’s could give doctors a new way to protect high-risk people who haven’t been inoculated or who may not respond well to vaccination, such as those taking drugs that weaken their immune system. That could be an important tool as rising coronavirus cases and dangerous virus variants threaten to outpace vaccinations.
Regeneron said in a news release that it would ask the Food and Drug Administration to expand the drug’s emergency authorization — currently for high-risk people who already have Covid but are not hospitalized — to allow it to be given for preventive purposes in “appropriate populations.”
There’s “a very substantial number of people” in the United States and globally who could be a good fit to receive these drugs for preventive purposes, said Dr. Myron Cohen, a University of North Carolina researcher who leads monoclonal antibody efforts for the Covid Prevention Network, a National Institutes of Health-sponsored initiative that helped to oversee the trial.
“Not everyone’s going to take a vaccine, no matter what we do, and not everyone’s going to respond to a vaccine,” Dr. Cohen said.
Regeneron’s new data come from a clinical trial that enrolled more than 1,500 people who lived in the same household as someone who had tested positive for the virus within four days. Those who got an injection of Regeneron’s drug were 81 percent less likely to get sick with Covid compared to volunteers who got a placebo.
Dr. Rajesh Gandhi, an infectious diseases physician at Massachusetts General Hospital who was not involved in the study, said the data were “promising” for people who have not yet been vaccinated. But he said that the study did not enroll the type of patients that would be needed to assess whether the drug should be used preventively for immunocompromised patients. “I would say we don’t yet know that,” Dr. Gandhi said.
Regeneron’s cocktail, a combination of two drugs designed to mimic the antibodies generated naturally when the immune system fends off the virus, got a publicity boost last fall when it was given to President Donald J. Trump after he got sick with Covid.
The treatment received emergency authorization in November. Doctors are using it, as well as another antibody cocktail from Eli Lilly, for high-risk Covid patients.
But use of the antibody drugs has been slowed not by a shortage of doses, but by other challenges, though access has improved in recent months. Many patients don’t know to ask for the drugs or where to find them.
Many hospitals and clinics have not made the treatments a priority because they have been time-consuming and difficult to administer, in large part because they must be given via intravenous infusion. Regeneron plans to ask the F.D.A. to allow its drug to be given via an injection, as it was administered in the results of the study announced on Monday, which would allow it to be given more quickly and easily.
Britain reopened large parts of its economy on Monday, allowing people in England back in shops, hair salons and outdoor areas of pubs and restaurants, a long-awaited milestone after three months of lockdown, and a day after the country recorded its lowest daily coronavirus death toll since September.
Under the second stage of the government’s gradual reopening, libraries, community centers and some outdoor attractions like zoos will also return, though outdoor gatherings remain limited to six people or two households.
For many in England, the return was a hopeful — if not definitive — sign that the worst of the pandemic was behind them, after a new variant of the virus detected last year in the country’s southeast spun out of control around Christmas, overwhelming hospitals and causing tens of thousands of deaths.
At its winter peak, Britain reported as many as 60,000 daily cases a day and 1,820 daily deaths, according to a New York Times database. But after months of restrictions and an aggressive vaccination program that has offered a dose to about half of Britain’s population, those figures declined to 1,730 daily cases and seven deaths reported on Sunday.
Prime Minister Boris Johnson has so far gone ahead with the gradual easing of measures that he had announced, reopening schools on March 8, reducing restrictions on outdoor gatherings on March 29, and allowing large parts of the economy to reopen on Monday.
Mr. Johnson said on Monday that the reopening was “a major step forward in our road map to freedom.” Still, he urged caution.
“I urge everyone to continue to behave responsibly and remember ‘hands, face, space and fresh air’ to suppress Covid,” he said.
Scotland, Wales and Northern Ireland, where devolved governments are responsible for coronavirus restrictions, have laid out similar plans to reopen their economies.
The apparent success represents a turnaround for Mr. Johnson’s government, which struggled to stem cases earlier in the pandemic and at one point reported the greatest rate of excess deaths in Europe.
But now E.U. countries — hampered by a vaccine rollout slower than Britain’s and a scare over a possible links between the AstraZeneca vaccine and blood clots — are facing a third wave of coronavirus infections. France, Italy and other countries have recently imposed new lockdown measures.
In England, business owners reopened on Monday with hope — and some anxiety that the numbers of infections could go up again. Still, “we’re looking confident we won’t be seeing anything like that again,” said Nicholas Hair, the owner of The Kentish Belle, a London pub that opened its doors to patrons one minute after midnight.
Even as India hit a record for daily coronavirus infections, and its total caseload rose to second in the world behind the United States, the images that dominated Indian news media on Monday were of a crowded religious festival along the banks of the Ganges River.
The dissonance was a clear manifestation of the confusing messages sent by the authorities just as India’s coronavirus epidemic is spiraling, with a daily high of 168,000 cases and 900 deaths reported on Monday.
Yet millions of devotees have thronged the holy city of Haridwar for the monthlong Kumbh Mela, or pitcher festival, when Hindu pilgrims seek absolution by bathing in the Ganges. Officials have said that about one million people will participate every day, and as many as five million during the most auspicious days, all crowded into a narrow stretch along the river and searching for the holiest spot to take a dip.
Already, fears are running high that one of the most sacred pilgrimages in Hinduism could turn into a superspreading event.
Dr. S. K. Jha, a local health officer, said that an average of about 250 new cases had been registered each day recently. Experts have warned that many more infections are going unrecorded, and that devotees could unwittingly carry the virus with them as they return to their homes across the country.
India is in the grip of the world’s fastest growing outbreak, with more and more jurisdictions going back into varying stages of lockdown. Infections are spreading particularly fast in Mumbai, the country’s financial hub, and the surrounding state of Maharashtra, where the government has announced a partial weekday lockdown and near-total closure over the weekends.
The situation is also worsening in the capital, New Delhi, which reported more than 10,000 new cases on Sunday, surpassing the previous daily high of nearly 8,500. The state government has imposed a curfew and ordered restaurants and public transport systems to run at half capacity. Arvind Kejriwal, Delhi’s top official, has said more restrictions may follow.
Hospitals in several states are reporting shortages of oxygen, ventilators and coronavirus testing kits, and some are also running low on remdesivir, a drug used in serious Covid-19 cases. India has halted the export of remdesivir until the situation improves.
India is also trying to ramp up its vaccination drive, with about three million people being inoculated daily and 104 million doses administered so far. But with many vaccination centers nationwide expressing concern over possible shortages, India’s large pharmaceutical industry has sharply reduced its exports of the AstraZeneca vaccine in order to keep more doses at home, creating serious challenges for other countries that had been relying on those shipments.
On Monday, Indian experts recommended the use of Russia’s Sputnik-V coronavirus vaccine, which would become the third available in the country if approved by the authorities.
After months of lower-than-expected infections and deaths from the virus, critics say Indian officials have sent dissonant messages about the seriousness of the crisis. Police officers are enforcing curfew and mask rules, sometimes resorting to beatings captured on videos shared across social media. But senior political leaders, including the prime minister, Narendra Modi, have been holding large rallies for local elections.
Mr. Modi’s Hindu nationalist government has also allowed the religious festival to proceed — in contrast to what happened last spring, at the start of the pandemic, when India’s health ministry blamed an Islamic seminary for fanning a far smaller outbreak. Critics say rhetoric from members of Mr. Modi’s party contributed to a spate of attacks against Muslims, a minority of about 200 million people in a Hindu-dominated country of 1.3 billion.
In other news around the world:
Bangladesh has announced a weeklong lockdown, closing offices, factories and transport services starting Wednesday, and banning domestic and international flights. The country is facing its severest coronavirus outbreak so far, averaging nearly 7,000 daily new infections, according to a New York Times database, as the virus sweeps across South Asia.
In France, all people over 55 are eligible to receive the AstraZeneca and Johnson & Johnson vaccines starting Monday, as the authorities try to ramp up their vaccination campaign after a sluggish start. Health Minister Olivier Véran said on Sunday that France would also extend the period between the first and second shots of the Pfizer and Moderna vaccines to six weeks from four, echoing Britain’s strategy. Over 14 million people have received a first injection.
High schools reopened in Greece on Monday after five months closed. The reopening only applies to senior high-school classes, and pupils and teachers will have to take a virus test twice a week before returning to classrooms. Thousands did so at home on Sunday, with just 613 positives out of some 380,000, a rate of 0.16 percent, according to state television. Stores in the country reopened last week.
The world’s wealthy nations should commit $30 billion to a global mass vaccination campaign, Gordon Brown, a former prime minister of Britain, said on Monday. Lower-income countries’ inoculation efforts are trailing far behind richer nations’ and the divide has led to allegations of a “vaccine apartheid,” Mr. Brown warned in an op-ed for The Guardian. “The costs may still be in billions, but the benefit will be in trillions,” he wrote.
Anna Schaverien, Constant Méheut and Niki Kitsantonis contributed reporting.
Australia has given up on the goal of vaccinating its entire population against Covid-19 by the end of the year, following updated advice from health officials that younger people should not receive the AstraZeneca vaccine, as well as delays in the delivery of doses.
The Australian government said last week that it had accepted a recommendation by a panel of health experts that people under 50 receive the Pfizer-BioNTech vaccine instead of the one developed by AstraZeneca, which had been the centerpiece of Australia’s vaccination program. The change in guidance came after European regulators found links between the AstraZeneca vaccine and rare blood clots, prompting several countries to restrict use of the shot.
Prime Minister Scott Morrison said Friday that the government had ordered another 20 million doses of the Pfizer vaccine, doubling what it had already purchased. But they are not expected to be available until the fourth quarter of this year, dealing a blow to the government’s previously stated goal of inoculating all of its 25 million people by then.
Mr. Morrison appeared to acknowledge the change in timeline in a Facebook post on Sunday.
“The government has also not set, nor has any plans to set any new targets for completing first doses,” Mr. Morrison said. “While we would like to see these doses completed before the end of the year, it is not possible to set such targets given the many uncertainties involved.”
Public health experts have criticized Mr. Morrison’s government for relying too heavily on the AstraZeneca vaccine, a relatively cheap and easy-to-use shot but one whose troubles have jeopardized inoculation efforts in multiple countries. They said the setback to Australia’s vaccination program risked undermining the country’s success in containing the spread of the coronavirus since recording its first case in January 2020.
“We’re in a position a year later where that hard-won success is jeopardized by a completely incompetent approach to a vaccine rollout,” said Bill Bowtell, a public health policy expert and adjunct professor at the University of New South Wales in Sydney.
Australia has made four separate agreements for the supply of Covid-19 vaccines that would give it a total of 170 million doses, enough to inoculate its population more than three times over. Plans to manufacture almost all of its 54 million AstraZeneca doses domestically were approved last month.
But the Australian government has been under fire for weeks over the sluggish pace of its vaccination rollout, which began in late February. By the end of March, when the government had aimed to vaccinate four million people, only about 600,000 had actually been inoculated. As of Sunday, Australia had administered fewer than 1.2 million doses.
Australian officials have attributed the slow rollout to delays in the delivery of millions of vaccine doses manufactured in the European Union, which has curbed exports amid its own supply shortages. The export restrictions mainly affect the AstraZeneca vaccine.
After enduring strict lockdowns for much of the past year, Australians are now enjoying relatively normal life in a country that has all but stamped out the virus. But public health experts warn that until more of the population is vaccinated, those freedoms are precarious.
“Having eliminated Covid, they thought a mass vaccination campaign would lock that in,” Mr. Bowtell said of the Australian public. “Now they are being deeply disillusioned.”
Thailand is facing its worst coronavirus outbreak just as millions of people head to their home provinces during the country’s biggest travel holiday.
The latest wave of infections, which has sent at least eight cabinet members into isolation, is centered in a Bangkok nightlife district said to be popular with government officials and wealthy partygoers. The country, which until now has largely kept the virus under control, set a record Monday for new daily cases with 985.
One top health official warned that Thailand could soon face as many as 28,000 new cases a day in the worst-case scenario. The government announced it would set up field hospitals as Covid-19 wards at existing facilities begin to fill up.
Officials ordered the closure of hundreds of bars and nightclubs, but critics say the government has been inconsistent in its efforts to bring the outbreak under control. The prime minister, Prayuth Chan-ocha, stopped short of banning travel between provinces for the Songkran holiday, which begins on Tuesday and marks the beginning of the Thai New Year.
“Whatever will be, will be,” he said last week in explaining his decision. “The reason is it’s a matter that involves a huge number of people. The government will have to try to cope with that later.”
Dozens of provinces have imposed their own restrictions on travelers coming from Bangkok and other affected areas, prompting many Thais to cancel their trips. But many others set off over the weekend.
During earlier outbreaks, the government often acted quickly to require face masks, ban foreign tourists, impose quarantine restrictions and lock down hard-hit areas. It has reported fewer than 34,000 cases — mostly from a January surge traced to a seafood market near Bangkok — and just 97 deaths.
But it has been lax in testing and slow to vaccinate. So far, it has procured about 2.2 million doses and given at least one to about 500,000 people. Thailand’s population is 70 million.
Vaccine production is not expected to begin in earnest until June, when a manufacturer in Thailand is scheduled to begin producing 10 million doses a month of the AstraZeneca vaccine.
Health officials were alarmed by the recent discovery of dozens of cases of the highly infectious coronavirus variant first identified in Britain. The finding highlighted the inadequacy of Thailand’s virus testing and suggested that its quarantine procedures have not been as effective as officials believed.
Tourism operators have been especially angered by the government’s lackadaisical approach to obtaining vaccine supplies. The tourism industry, which normally accounts for about 20 percent of the nation’s economy, is highly dependent on foreign visitors and has been calling for widespread vaccinations to speed its recovery.
The outbreak in Bangkok has also prompted questions about the activities of some top officials and their aides.
The transportation minister, Saksayam Chidchob, who was hospitalized with Covid-19, was criticized for not being forthcoming about his whereabouts during times when he may have been exposed to the virus. He denied visiting the gentlemen’s club at the center of the outbreak and said he believed he had contracted the virus from an aide.