LONDON — With a rapid rollout of spectacularly successful vaccines, the path seemed clear not long ago for Prime Minister Boris Johnson to scrap all of England’s coronavirus rules on June 21, ending curbs that he resisted imposing in the first place.
But on Monday, Mr. Johnson postponed by four weeks the moment dubbed “freedom day” by the tabloids after a spike in cases of a highly transmissible new variant that may cause more serious disease than earlier variants. Restaurants and pubs in England, while open, will still have to observe social distancing rules indoors, limiting capacity, and nightclubs and theaters will remain firmly shuttered.
The decision, which will be reviewed in two weeks, sent a warning to the world that even well-vaccinated nations remain at risk and angered a noisy caucus of libertarian lawmakers within Mr. Johnson’s own party.
At present new cases are averaging around 8,000 per day and are doubling every week. Hospital admissions have begun rising. And the impact of the Delta variant across England has already sparked alarm in other European countries including Germany, which has introduced a travel ban.
In Britain around four-fifths of adults have received one dose and more than half have had the second shot. But people with only a single dose remain susceptible to cases of the Delta variant — more so than to earlier versions of the virus, scientists said. And an unabated surge of infections in younger, unvaccinated people could ignite a dangerous wave of hospitalizations.
That has helped convince many epidemiologists that lifting restrictions now could, in a worst-case scenario, produce as many hospital cases as in the first wave of the pandemic, overwhelming the National Health Service just as it is trying to cope with a backlog of procedures that were postponed during the pandemic.
Since first being sampled in Britain almost four months ago, the Delta variant, which was first detected in India, has swept across the country, outcompeting even the dangerous variant called Alpha that took hold earlier. Recent studies show that 96 percent of new infections now are with the Delta variant.
Scientists remain at odds over exactly how serious a threat it poses, however, with some arguing that the most dire predictions about rising hospitalizations underestimate the effect even the current level of vaccinations have on breaking the link between the number of new infections and hospitalizations and deaths.
The optimists could point to reassuring news Monday from Public Health England: Full courses of the Pfizer and AstraZeneca vaccines offer extremely strong protection against hospitalization in cases of the Delta variant.
Novavax, a small American company buoyed by lavish support from the U.S. government, announced on Monday the results of a clinical trial of its coronavirus vaccine in the United States and Mexico, finding that its two-shot inoculation provided potent protection against the coronavirus.
In the 29,960-person trial, the vaccine demonstrated an overall efficacy of 90.4 percent, on par with the vaccines made by Pfizer-BioNTech and Moderna, and higher than the one-shot vaccine from Johnson & Johnson. The Novavax vaccine showed an efficacy of 100 percent at preventing moderate or severe disease.
Despite the impressive results, the vaccine’s future in the United States is uncertain and it might be needed more in other countries. Novavax says it may not seek emergency authorization from the Food and Drug Administration until the end of September. And with a plentiful supply of three other authorized vaccines, it’s possible that the agency may tell Novavax to apply instead for a full license — a process that could require several extra months.
The company’s chief executive, Stanley Erck, acknowledged in an interview that Novavax would probably win its first authorization elsewhere. The company is also applying in Britain, the European Union, India and South Korea.
“I think the good news is that the data are so compelling that it gives everybody an incentive to pay attention to our filings,” Mr. Erck said.
By the time Novavax gets the green light from the U.S. government, it may be too late to contribute to the country’s first wave of vaccinations. But many vaccine experts expect that, with waning immunity and emerging variants, the country will need booster shots at some point. And the protein-based technology used in the Novavax vaccine may do a particularly good job at amplifying protection, even if people have previously been vaccinated with a different formulation.
“They may be really the right ones for boosters,” said Dr. Luciana Borio, who was the acting chief scientist at the F.D.A. from 2015 to 2017.
Last year, the Trump administration’s Operation Warp Speed program awarded Novavax a $1.6 billion contract for 100 million future doses. The company won this tremendous support despite not having brought a vaccine to market in over three decades.
In January, Novavax announced that its 15,000-person trial in Britain found that the vaccine had an efficacy of 96 percent against the original coronavirus. Against Alpha, a virus variant first identified in Britain, the efficacy fell slightly to 86 percent. In South Africa, where the Beta variant was dominant, Novavax ran a smaller trial on 2,900 people and found an efficacy of just 49 percent.
But the South Africa trial was complicated by the fact that a number of the volunteers had H.I.V., which is known to hamper vaccines. In addition, the study was so small that it was difficult to estimate how much protection the vaccine provided H.I.V.-negative volunteers.
With the support of Operation Warp Speed, Novavax drew up plans for an even larger late-stage trial in the United States and Mexico. But difficulties with manufacturing delayed its start until December.
By then, the United States had authorized the Pfizer-BioNTech and Moderna vaccines. In February, with the Novavax trial still underway, the government authorized Johnson & Johnson’s.
BANGKOK — For months, the government of Thailand assured citizens that a plan to dole out free, locally made coronavirus shots would start in early June. About 70 percent of the national population would be inoculated by the end of the year, health officials said.
Then the delays began, just as the country was struggling with its worst outbreak of the coronavirus since the start of the pandemic.
On Sunday night, nearly a week after the vaccination program was supposed to have kicked into high gear, hospitals in Bangkok announced that previously confirmed appointments had been canceled.
There was no word as to why or when they might be rescheduled.
The knock-on effect of what appears to be a mass shortage of Thai-made vaccines is also radiating to other parts of the region, where inoculation campaigns are far behind those of many Western countries. The governments of Malaysia, the Philippines and Taiwan have announced that they are scaling back their vaccine rollouts because of lower-than-expected shipments from Thailand. (Thailand disputed the claims that it was to blame.)
Last year, Thailand was designated the regional hub for local production of the AstraZeneca shots. A contract was awarded to Siam Bioscience, a pharmaceutical firm with no prior experience in manufacturing vaccines. The company is controlled by the king of Thailand.
Prime Minister Prayuth Chan-ocha of Thailand has warned that criticism of the company could be considered a criminal offense under the kingdom’s strict royal defamation laws. An opposition politician who questioned how Siam Bioscience got such a contract was charged with lèse-majesté — wronging the monarch — this year.
Although Thailand was the first country to record a coronavirus case outside of China, in January 2020, the country suppressed the virus’ rampant spread for most of that year. Late in 2020, the country had recorded fewer than 5,000 total cases of the coronavirus.
But Thailand is now dealing with thousands of new cases each day. As of Monday, only about 3 percent of the population had been fully inoculated.
Phatorn Chingduang, a shipping company employee, was supposed to get his first dose of AstraZeneca on June 12, along with about 15 others at his company. The day before the shots were to be administered, he was sent a text canceling the appointment.
“I don’t see the government doing enough,” Mr. Phatorn said. “This vaccine drama, it’s so bad.”
Recriminations are ricocheting. At least five Bangkok hospitals said on Monday that they did not have enough doses. All vaccines in Thailand are being distributed by the Ministry of Public Health.
The ministry countered by saying that it had sent out promised doses to the local authorities, who were responsible for specific hospital allocations. Vaccines for at least 50 million people have already been procured, said Opas Karnkawinpong, the director general of the department of disease control, on Monday.
The same day, Aswin Kwanmuang, the governor of Bangkok, alluded to “technical difficulties” and said that mass vaccinations in the capital would be suspended on June 15.
“Bangkok will stop the vaccinations and will resume the inoculations as soon as we receive the vaccines,” he said.
On Monday, as factories and prisons in the Bangkok area struggled with mounting outbreaks, officials said that parks and museums would reopen in the capital, loosening a monthslong lockdown.
Also open for business again? Tattoo parlors and foot massage salons.
In Germany, where infection rates have been steadily falling for weeks, masks are still obligatory nearly everywhere, including on downtown sidewalks and at many outdoor venues, such as farmers’ markets. Depending on the state, the rules are even more stringent for riding public transport, shopping or entering public buildings, with medical-grade face coverings often required.
But in an indication that masks may start coming off soon in Germany, the country’s health minister, Jens Spahn, said on Monday that states could start setting their own policies — at least for outdoor areas — as the average number of recorded infections drops under 1,000 per day.
“With the falling infection rates, we should proceed in stages: In a first step, the mask requirement outside can be dropped in general,” Mr. Spahn said in an interview with the Funke group of newspapers.
Germany has recently reopened restaurant terraces, beer gardens and outdoor dining, and most states have started opening indoor dining — but only for those who can show that they have been vaccinated or tested negative. Museums are also now open to visitors.
Although individual states make the final rules, governors look to Berlin — and each other — for guidance on coronavirus restrictions.
On Sunday, Germany registered 549 new cases; in December, before the country’s vaccination drive, cases had reached a daily average of more than 30,000. Currently, 48.4 percent of the population has received a first shot, and 26.2 percent are fully vaccinated.
In an interview on Sunday, Wolfgang Kubicki, a centrist lawmaker with the opposition Free Democratic Party, called for completely abandoning mask rules in areas where there were fewer than 35 new cases a week per 100,000 people. (Currently, Germany is averaging 16.6 cases per 100,000 in a week — and most regions would fall below the threshold of 35.)
But others have expressed more caution, warning that mask rules are still important.
“Completely dropping mask requirements just before millions are vaccinated is just one thing: electioneering on the backs of the health of the citizens,” the Social Democratic lawmaker Karl Lauterbach wrote on Twitter. Mr. Lauterbach, whose party is a member of the governing coalition, has a public health degree from Harvard and has become one of the country’s most prominent experts on the pandemic.
He added: “Of course, the mask requirement outdoors can be waived almost everywhere. There is no superspreading outdoors.”
A federal judge in Texas has dismissed a lawsuit brought by employees of Houston Methodist Hospital who had challenged the hospital’s coronavirus vaccination requirement.
U.S. District Judge Lynn N. Hughes, in the Southern District of Texas, issued a ruling on Saturday that upheld the hospital’s new policy, announced in April. The judge said that the hospital’s decision to mandate inoculations for its employees was consistent with public policy.
And he rejected a claim by Jennifer Bridges, a nurse and the lead plaintiff in the lawsuit, that the vaccines available for use in the United States were experimental and dangerous.
“The hospital’s employees are not participants in a human trial,” Judge Hughes wrote. “Methodist is trying to do their business of saving lives without giving them the Covid-19 virus. It is a choice made to keep staff, patients and their families safer.”
The judge’s decision appeared to be among the first to rule in favor of employer-mandated vaccinations for workers. Several major hospital systems have begun to require Covid shots, including in Washington, D.C., and Maryland.
But many private employers and the federal government have not instituted mandatory immunization as they shift operations back to office settings. This year, the Equal Employment Opportunity Commission issued guidance allowing employers to require vaccines for on-site workers.
In Houston, Ms. Bridges was among those who led a walkout on Monday, the hospital’s deadline for getting the vaccine. And on Tuesday, the hospital suspended 178 employees who refused to get a coronavirus shot.
Ms. Bridges cited the lack of full Food and Drug Administration approval for the shot as justification for refusing to get vaccinated. But the F.D.A., which has granted emergency use authorizations for three vaccines, says clinical trials and post-market study shows they are safe, as does the Centers for Disease Control and Prevention.
The judge also noted that Texas employment law only protects employees from termination for refusing to commit an act that carries criminal penalties.
“Bridges can freely choose to accept or refuse a Covid-19 vaccine, however if she refuses, she will simply need to work somewhere else,” he said, also rejecting the argument that employees were being coerced.
And the judge called “reprehensible” the lawsuit’s contention that a vaccination requirement was akin to medical experimentation during the Holocaust.
In a statement late Saturday, Dr. Marc Boom, chief executive of Houston Methodist, said: “Our employees and physicians made their decisions for our patients, who are always at the center of everything we do.”
Houston Methodist said it would begin proceedings to terminate employees who were suspended if they did not get vaccinated by June 21.
Jared Woodfill, the employee plaintiffs’ lawyer, also issued a statement on Saturday, according to news reports, that indicated the workers would appeal the ruling.
Even as the pandemic recedes and cities reopen, local leaders across the United States face another crisis: a crime wave with no signs of ending.
Mayors are trying to quell a surge of homicides, assaults and carjackings that began during the pandemic and has cast a chill over the recovery. Homicide rates in large cities were up more than 30 percent on average last year, and up another 24 percent for the beginning of this year, according to criminologists.
Some city officials have touted progressive strategies focused on community policing in neighborhoods where trust between officers and residents has frayed. Others have deployed more traditional tactics like increasing surveillance cameras in troubled areas and enforcing curfews in city parks to clear out crowds, as the police did in Washington Square Park in Manhattan in recent days.
In Chicago, which fully reopened on Friday, Mayor Lori Lightfoot made clear that her focus was on reducing violence over the summer, and that her administration would focus resources on 15 high-crime pockets of the city as part of that effort.
“We owe it to all of our residents, in every neighborhood, to bring peace and vibrancy back,” Ms. Lightfoot said.
Homicides in Miami are 30 percent higher this year than the same period in 2020, according to data from the medical examiner’s office.
This month, the top prosecutor in Miami-Dade County and local police leaders turned to the issue of public safety, announcing efforts that include additional streetlights and surveillance cameras, prosecutors assigned to “hot spot” areas and a code enforcement crackdown on illegal party venues.
To a growing chorus of American politicians and scientists, she is the key to whether the world will ever learn if the virus behind the devastating Covid-19 pandemic escaped from a Chinese lab. To the Chinese government and public, she is a hero of the country’s success in curbing the epidemic and a victim of malicious conspiracy theories.
Shi Zhengli, a top Chinese virologist, is once again at the center of clashing narratives about her research on coronaviruses at a state lab in Wuhan, the city where the pandemic first emerged.
The idea that the virus may have escaped from a lab had long been widely dismissed by scientists as implausible, and has been shunned by others for its connection with former President Donald J. Trump. But fresh scrutiny from the Biden administration, and calls from prominent scientists for greater candor on China’s part, have brought the theory back to the fore.
Scientists generally agree that there is still no direct evidence to support the lab leak hypothesis. But more of them now say that the idea was dismissed too hastily without a thorough investigation, and they point to a range of unsettling questions.
Some scientists say Dr. Shi conducted risky experiments with bat coronaviruses in labs that were not safe enough for such work. Others want clarity on reports, citing American intelligence, suggesting that there were early infections of Covid-19 among employees of the Wuhan Institute of Virology.
Dr. Shi has denied these accusations, and now finds herself defending the reputation of her lab and, by extension, that of her country
The speculation boils down to one central question: Did Dr. Shi’s lab hold any source of the new coronavirus before the pandemic erupted? Dr. Shi’s answer is an emphatic no.
But China’s refusal to allow an independent investigation into her lab, or to share data on its research, makes it difficult to validate Dr. Shi’s claims, and has fueled nagging suspicions about whether it could be mere coincidence that the first place the pandemic took hold was a city that hosts an institute known for its work on bat coronaviruses.
On her first day as director of the Centers for Disease Control and Prevention in January, Dr. Rochelle Walensky ordered a review of all Covid-related guidance on the agency’s website. Some of its advice had been twisted by the Trump administration, and her message was clear: The C.D.C. would no longer bend to political meddling.
Four months later, Dr. Walensky announced that vaccinated people could stop wearing masks in most settings. The recommendation startled not just the White House but also state and local leaders, prompting criticism that she had failed to prepare Americans for the agency’s latest about-face during the pandemic.
The two announcements captured the challenge that will define Dr. Walensky’s tenure at the C.D.C.: restoring an agency once renowned as the world leader in public health but whose reputation has been battered by political interference, even as the country transitions out of a pandemic that has left nearly 600,000 Americans dead.
President Biden had promised that the C.D.C. director he chose would be free to make scientifically grounded decisions without interference from politicians. Dr. Walensky, a widely respected infectious disease expert known for her battles with drug companies over prohibitive prices, seemed ideally suited.
Dr. Walensky’s appointment instantly made her one of the most influential women in the nation, and was greeted with enthusiasm by public health experts and C.D.C. staff members. But that enthusiasm has been tempered by occasional missteps in communications, an aspect of the job that is more important and challenging than it has ever been.
“Rochelle at baseline is an excellent communicator, but I think in a situation this fraught — politically, operationally and how quickly the science moves — you’re going to make mistakes,” said Dr. Celine Gounder, a former adviser to Mr. Biden’s team on Covid-19. “The question is, how does she acknowledge those and learn from those and move forward from there?”