As the Delta variant sweeps the world, researchers are tracking how well vaccines protect against it — and getting different answers.
In Britain, researchers reported in May that two doses of the Pfizer-BioNTech vaccine had an effectiveness of 88 percent protecting against symptomatic disease from Delta. A June study from Scotland concluded the vaccine was 79 percent effective against the variant. On Saturday, a team of researchers in Canada pegged its effectiveness at 87 percent.
And on Monday, Israel’s Ministry of Health announced that the effectiveness of the Pfizer-BioNTech vaccine was 64 percent against all coronavirus infections, down from about 95 percent in May, before the Delta variant began its climb to near-total dominance in Israel.
Although the range of these numbers may seem confusing, vaccine experts say it should be expected because it’s hard for a single study to accurately pinpoint the effectiveness of a vaccine.
“We just have to take everything together as little pieces of a puzzle, and not put too much weight on any one number,” said Natalie Dean, a biostatistician at Emory University.
In clinical trials, it’s (relatively) easy to measure how well vaccines work. Researchers randomly assign thousands of volunteers to get either a vaccine or a placebo. If the vaccinated group has a lower risk of getting sick, scientists can be confident that it’s the vaccine that protected them.
But once vaccines hit the real world, it becomes much harder to measure their effectiveness. Scientists can no longer control who receives a vaccine and who does not. If they compare a group of vaccinated people to a group of unvaccinated people, there could be other differences between the two groups that influence their risks of getting sick.
It’s possible, for example, that people who choose not to get vaccinated may be more likely to put themselves in situations where they could get exposed to the virus. On the other hand, older people may be more likely to be vaccinated, but also have a harder time fending off an aggressive variant. Or an outbreak may hit part of a country where most people are vaccinated, leaving under-vaccinated regions unharmed.
One way to rule out these alternative explanations is to compare each vaccinated person in a study with a counterpart who did not get the vaccine. Researchers often go to great lengths to find an unvaccinated match, looking for people who are of a similar age and health. They can even match people within the same neighborhood.
“It takes a huge effort,” said Marc Lipsitch, an epidemiologist at the Harvard T.H. Chan School of Health.
For its new study, Israel’s Ministry of Health did not go to such great lengths to rule out other factors. “I am afraid that the current Israeli MoH analysis cannot be used to safely assess it, one way or another,” Uri Shalit, a senior lecturer at the Technion — Israel Institute of Technology, wrote on Twitter.
Israel’s numbers could also be different because of who is getting tested. Much of the country is vaccinated. During local bursts of new infections, the government requires testing for anyone — symptoms or not — who came into contact with a person diagnosed with Covid-19. In other countries, it’s more common for people to get tested because they’re already feeling sick. This could mean that Israel is spotting more asymptomatic cases in vaccinated people than other places are, bringing their reported effectiveness rate down.
Fortunately, all the studies so far agree that most Covid-19 vaccines are very effective at keeping people out of the hospital and have generally protected against the Delta variant. Israel’s Ministry of Health estimated that the Pfizer-BioNTech vaccine is about 93 percent effective in preventing serious illness and hospitalization.
“Their overall implications are consistent: that protection against severe disease remains very high,” said Naor Bar-Zeev, an associate professor at the Johns Hopkins Bloomberg School of Public Health.
Because effectiveness studies are so tricky, it will take more work to determine just how big of a threat Delta poses to vaccines. Dr. Lipsitch said that studies from more countries would be required.
“If there are five studies with one outcome and one study with another, I think one can conclude that the five are probably more likely to be correct than the one,” Dr. Lipsitch said.
WASHINGTON — With the pace of U.S. coronavirus vaccinations relatively flat, President Biden called on Tuesday for employers to set up clinics at work and to offer paid time off for workers as part of a renewed push to reach tens of millions of Americans who remain unvaccinated.
“Please get vaccinated now — it works, it’s free, it’s never been easier,” Mr. Biden said in brief remarks. “It’s never been more important. Do it now for yourself and the people you care about — for your neighborhood, for your country. It sounds corny, but it’s a patriotic thing to do.”
Just two days after he hosted a big White House Fourth of July celebration and declared “America is coming back together,” Mr. Biden is turning his attention to a public health conundrum: Despite his administration’s aggressive push, he has not met his self-imposed goal of having 70 percent of adults at least partially vaccinated by now, and officials have already tried many techniques.
In his remarks, Mr. Biden noted a different metric: By the end of the week, nearly 160 million Americans, not quite half the population, will be fully vaccinated. The worrisome Delta variant spreading quickly around the country remains a concern in areas with lower vaccination rates. Although there is not yet good data on how all of the vaccines hold up against Delta, several widely used shots, including those made by Pfizer-BioNTech, are still effective against the Delta variant after two doses, research suggests.
But providers were administering about 0.87 million doses per day on average, as of Tuesday, about a 74 percent decrease from the peak of 3.38 million reported on April 13.
And beyond the issues with the vaccination campaign, declines in the virus itself appear to have stalled nationally. After a sharp drop in virus cases, the average number of new daily cases across the country seems to have leveled off and remain close to the lowest point since testing became widely available. Mr. Biden underscored that overall progress in his remarks on Tuesday, but pockets of outbreaks remain. In some parts of Texas, Arkansas and Missouri, for instance, there has been a sharp rise in cases.
Mr. Biden used his remarks to outline five areas of concentration for his administration, all avenues it has already pursued: targeted, community by community, door to door outreach to get the remaining Americans vaccinated; a fresh push to get vaccines to primary care doctors; a boost in efforts to get vaccines to pediatricians and other providers who serve younger people so that adolescents ages 12 to 18 can get their shots; expanded mobile clinic efforts and the workplace changes.
“The bottom line is, my administration is doing everything we can to lead a whole-of-government response at the federal, state and local levels to defeat the pandemic,” he said. “We need everyone to do their part.”
More than 125 children and adults who attended a religious camp in Texas last month have now tested positive for Covid-19, camp officials said this week in a statement that also warned that many more people may have been exposed to the virus.
In addition to the 125 people who tested positive, “hundreds more were exposed to COVID-19 at camp,” Bruce Wesley, senior pastor for Clear Creek Community Church, wrote on the church’s website. The church is based in League City, about 30 miles southeast of Houston. “And hundreds of others were likely exposed when infected people returned home from camp.”
As of early May, masks were “optional in all areas,” according to the camp’s website. Telephone and email messages sent to the camp on Tuesday evening were not immediately returned.
“From the beginning of the pandemic, we have sought to love our neighbors by practicing strict safety protocols,” Mr. Wesley said in the statement. “We are surprised and saddened by this turn of events. Our hearts break for those infected with the virus.”
More than 400 people participated in the student ministry camp, according to the statement. The camp also said it has consulted with the Galveston County Health District and canceled services for now, but will resume activities on Sunday, July 11.
In a statement on Tuesday, Galveston health officials said the Delta variant of the virus was detected in three test samples linked to “a church camp.” Dr. Philip Keiser, Galveston County Local Health Authority, said, “In this outbreak, at least as of now, it appears most of the people who have tested positive are old enough to be vaccinated.” The camp served children in grades 6 through 12, it said.
News of the outbreak in Texas comes during the return of the traditional summer camp season, when day and sleep-away camps are about to welcome children who just completed a school year dramatically altered by Covid-19 health restrictions, and many children are looking for relief from the soaring summer temperatures.
In Illinois, 85 teenagers and adults tested positive for Covid-19 after attending a camp that did not check the vaccination records of participants or require masks indoors, the Illinois Department of Public Health said last month. At least 25 staffers at a Christian summer camp in Oklahoma tested positive for Covid-19 in June, Public Radio Tulsa reported.
Officials across the country have rolled back face-covering and social distancing rules that were put in place more than a year ago, even as new variants of the virus have quickly spread in areas with low vaccination rates. In Galveston, 44 percent of residents have been vaccinated, slightly above the statewide vaccination rate of 41 percent.
In guidance for people attending or operating youth camps, the Centers for Disease Control said in late May that “everyone” aged 12-years-old or older should get vaccinated, and camps “should be supportive of campers or staff who choose to wear a mask.”
As their populations swell nearly to prepandemic levels, U.S. immigration detention centers are reporting major surges in coronavirus infections among detainees.
Public health officials, noting that few detainees are vaccinated against the virus, warn that the increasingly crowded facilities can be fertile ground for outbreaks.
The number of migrants being held in the detention centers has nearly doubled in recent months as border apprehensions have risen, according to the Immigration and Customs Enforcement agency. More than 26,000 people were in detention last week, compared with about 14,000 in April.
More than 7,500 new coronavirus cases have been reported in the centers over that same period, accounting for more than 40 percent of all cases reported in ICE facilities since the pandemic began, according to a New York Times analysis of ICE data.
Prisons and jails in America were hotbeds for the virus last year, with nearly one in three inmates at federal and state facilities testing positive. The virus infected and killed prisoners at a faster rate than it did in nearby populations because of crowding and other factors that made ideal conditions for Covid to spread.
As of May, according to ICE’s latest available data, only about 20 percent of detainees passing through the centers had received at least one dose of vaccine while in custody.
Dr. Carlos Franco-Paredes, an associate professor at the University of Colorado School of Medicine who has inspected immigration detention centers during the pandemic, said that several factors were to blame for the surge, including transfers of detainees between facilities, insufficient testing and lax Covid-19 safety measures.
For example, he said, during a recent inspection at a center in Aurora, Colo., he saw many staff members who were not wearing face coverings properly, adding: “There is minimal to no accountability regarding their protocols.”
Paige Hughes, an ICE spokeswoman, said that all new detainees were tested for the coronavirus and are held in quarantine for 14 days on arrival.
“On-site medical professionals are credited with reducing the risk of further spreading the disease by immediately testing, identifying and isolating the exposed detainees to mitigate the spread of infection,” she said.
Even so, public health officials point out that detainees are transported to the facilities by bus before they are tested and may be exposed during the trip. Similar lapses by prison systems over the past year have led to mass infections and deaths.
ICE officials said the agency’s policy was to leave decisions about vaccinating detainees to state and local officials. Some of the worst outbreaks at ICE facilities, including one at the Adams County Correctional Center in Natchez, Miss., have been in states where vaccination rates are far below the national average, according to a Times database.
As concerns grow over the spread of the more transmissible Delta variant of the coronavirus, Sharon Dolovich, a law professor and director of the Covid Behind Bars Data Project at the University of California, Los Angeles, said that detainees would remain vulnerable to outbreaks until officials made vaccinations at these sites a higher priority.
“You have people coming in and out of the facility, into communities where incomplete vaccination allows these variants to flourish, and then you bring them inside the facilities, and that variant will spread,” Dr. Dolovich said. “What you’re describing is the combination of insufficient vaccination plus the evolution of the virus, and that is really scary.”
Israel and South Korea have agreed to swap hundreds of thousands of doses of the Pfizer-BioNTech vaccine in the coming months to meet their countries’ needs, Israel’s prime minister, Naftali Bennett, said in a statement released Tuesday morning.
Under the deal, Israel will send about 700,000 expiring doses of the vaccine this month to South Korea, where cases of the virus are rising. South Korea will send the same amount to Israel in September and October, the statement said, describing the agreement as the first of its kind for the exchange of vaccines between Israel and another country.
Israel has had among the fastest vaccination programs in the world, fully inoculating 57 percent of its population so far, according to data from The New York Times. The deal with South Korea allows Israel to unload doses it doesn’t need immediately. It also will bolster Israel’s supply of vaccines for later in the year as officials grow increasingly concerned about the global spread of the Delta variant.
Mr. Bennett described it as “a win-win deal” that would “ensure that the State of Israel has a proper stock of vaccines.” He also thanked the chief executive of Pfizer, Albert Bourla, for helping to facilitate the deal.
The announcement came after the collapse of a deal between Israel and the Palestinian Authority in June. The authority had rejected more than one million doses of the vaccine on the grounds that they were too close to their expiration date. At the time, Ibrahim Melhem, a spokesman for the Palestinian Authority, said that the region would instead wait for a direct delivery of four million vaccine doses from Pfizer-BioNTech later in the year.
South Korea, which has fully vaccinated only 10 percent of its people, is trying to speed up its campaign. Average daily infections there have risen 42 percent over the past two weeks, according to New York Times data.
Signs of economic distress have begun appearing in neighborhoods across Kuala Lumpur and other Malaysian cities: white flags outside people’s houses, indicating that they need food or other assistance.
The flags — sometimes little more than T-shirts or strips of cloth — are a cry for help from mostly low-income families who are financially affected by the another long coronavirus lockdown. The campaign, shared on social media as #benderaputih (“white flag”), is a way for families to appeal for food, work or other essentials as many businesses remain closed and joblessness rises.
Thousands of people have stepped in, including artists and celebrities. A rapper who goes by Altimet pledged to his nearly 400,000 followers on Instagram last week that, every Friday, he would donate food and supplies to houses marked with a white flag.
Renyi Chin, a restaurant owner in Kuala Lumpur, the capital, said he had donated $1,000 worth of food and supplies to families in the past week.
“This is our fourth lockdown, and many have lost their jobs and means for food,” Mr. Chin said. Many of those afflicted by the latest restrictions are single mothers, older Malaysians and daily wage workers, he added.
As coronavirus cases continue to rise in Malaysia, with average daily infections up 19 percent in the last two weeks, according to New York Times data, the government on Saturday announced a tightening of restrictions in several regions, including Kuala Lumpur and most of Selangor state. The country had 6,539 daily cases last week, and just 8 percent of its population is fully vaccinated, according to Times data.
Malaysia’s repeated lockdowns have lowered demand for labor, with the number of registered jobs dropping by 130,000 in just the first quarter of the year, according to government data from the Department of Statistics Malaysia. Suicides have risen during the first five months of this year, and the health ministry said that the pandemic is partly to blame.
Many in Malaysia say the government has failed to manage the economic impact of the pandemic. Outside some houses, black flags have appeared in a separate campaign calling for the resignation of Prime Minister Muhyiddin Yassin.
“We’re in our fourth lockdown and yet the cases are rising,” Mr. Chin said. “Something isn’t right.”
Members of the governing party have dismissed the campaign, with one lawmaker, Nik Abduh Nik Aziz, asking people to pray instead of waving flags. “Don’t admit defeat when being tested by teaching the people to raise a white flag,” he said in a Facebook post last week.
Zuraida Kamaruddin, the minister for housing and local government, voiced support for the campaign in a tweet, writing: “There is no need to beg and no need to be embarrassed. Just raise the flag.”
Officials in Greece, a heavily tourism-dependent country that reopened to foreign visitors in May, announced stricter rules for the country’s bars and clubs on Tuesday, prompted by a sudden sharp increase in new Covid-19 infections. The surge in cases is fueling fears of a fourth wave of the pandemic at the height of the tourism season.
The Greek national public health organization, known as Eody, reported 1,797 new cases on Tuesday, more than double the current seven-day average, which has been climbing steadily in recent weeks. Officials attribute the spike to increased activity at bars and nightclubs, which have been operating outdoors since May with capacity limits and other safety measures.
The new rules for those venues, which take effect Thursday, say that bars and clubs can only serve customers who are seated. Businesses that fail to comply can be fined up to 10,000 euros and be ordered to close.
The aim of the new rules is to deter people from crowding tightly together in nightspots, and thus to “curb the transmission of the virus among the younger ages, so we can all have a summer that is safer and more free,” said Nikos Hardalias, the country’s deputy minister for civil protection. Mr. Hardalias noted that the average age of newly infected people has fallen to 27.
“Nothing is over,” he said. “We must vaccinate ourselves and protect our elders.”
Mr. Hardalias said that the more infectious Delta variant of the virus played a role in the spike, but did not indicate what proportion of the new cases were linked to the variant. “As in other countries, it’s only a matter of time until it becomes the predominant strain,” he said.
Greek authorities had been lifting restrictions over the past few weeks, after the waning of a spike in coronavirus cases in April. Death reports have fallen considerably and remain fairly low.
Around 37 percent of Greece’s 10.7 million people have been fully vaccinated so far. Medical experts have warned of further increases in infections unless authorities speed up vaccination efforts, particularly among young adults.
Portugal’s tourism industry received a boost late Monday when Germany said that it would lift a travel ban that had been recently introduced to help stop the spread of the Delta variant.
The Robert Koch Institute — Germany’s national disease control center — announced that Portugal, as well as Britain, Russia, India and Nepal, would be removed from a list of countries rated as being at the highest risk for travel. The change will take effect on Wednesday.
The Portuguese government had strongly criticized Germany’s earlier ban because it was the only nation on the list from the European Union. The bloc has been trying to align travel rules among its 27 member nations to help revive travel and tourism.
Just last week, Portugal reimposed curfews in several cities as the Delta variant surged through the country, another blow to some of its popular summer tourist destinations. The country has fully vaccinated about 37 percent of its total population, below the 47 percent in the United States, according to New York Times data.
In other developments across the world:
The authorities in the Spanish region of Catalonia on Tuesday announced the renewed closure of night clubs and other indoor entertainment spaces, a U-turn decided in response to a strong uptick in coronavirus cases. The restrictions will come into force Friday, but will not prevent outdoor music festivals and similar summer events from going ahead. The regional government of Catalonia — whose capital, Barcelona, is the tourism hub of Spain — also said that it would ask the central government to reintroduce the compulsory wearing of a face mask outdoors, which stopped being mandatory as recently as June 26. The rate of new cases has risen almost eightfold over the past two weeks in Catalonia.
Japan said it would send millions of doses of AstraZeneca’s Covid-19 vaccine to other parts of Asia this week, including 1.13 million doses for Taiwan, a self-governing island that China claims as its territory. Beijing, whose own vaccine offers to Taiwan have been rebuffed, had criticized the island’s officials for accepting a donation of 1.24 million doses from Japan last month. Premier Su Tseng-chang of Taiwan thanked Japan for the donations in a Facebook post on Tuesday, saying “True friends always lend a helping hand when they need each other the most.” Thailand, the Philippines and Vietnam will also receive about one million doses each this week, said Toshimitsu Motegi, the Japanese foreign minister. Last week, Japan delivered about one million free vaccine doses each to Malaysia and Indonesia, both of which are experiencing a surge in virus cases.
The Grand Prix and MotoGP, two of the biggest sporting events in Australia, will be canceled for the second year in a row after being planned for the fall. Martin Pakula, sports minister for Victoria state, said in a statement, “It’s very disappointing that these much-loved events can’t proceed but this is the reality of the pandemic — but until we get much higher vaccination rates we cannot return to more normal settings.” A cut to the number of international visitors allowed into Australia and continued quarantine requirements also contributed to the decision. Victoria has recorded no locally transmitted coronavirus cases for the past six days, but its neighboring state, New South Wales, is struggling to contain an outbreak in which the Delta variant has infected over 300 people.
Emergent BioSolutions has had to throw out 75 million Covid vaccine doses because of potential contamination, and production at its Baltimore factory has been halted for more than two months as the company tries to convince regulators that it has fixed serious quality problems.
As the federal government works with the biotech firm in an effort to restart production, some investors are asking for their money back and seeking an overhaul of the company’s corporate governance.
With its stock price cut in half, Emergent faces several shareholder lawsuits accusing it of securities fraud. A pension fund filed a complaint last Tuesday claiming that some executives and board members — including several former federal officials — had engaged in insider trading by unloading more than $20 million worth of stock over the past 15 months.
The executives and board members sold the stock “while in possession of material, nonpublic information that artificially inflated the price” and “profited from their misconduct and were unjustly enriched through their exploitation of material and adverse inside information,” the Illinois-based Lincolnshire Police Pension Fund asserted.
The litigation adds to the troubles of the politically connected company, which is also the target of a widening congressional investigation into its vaccine production problems and the favorable deals it has secured with the government.
An Emergent spokesman said all of the lawsuits were “without merit” but declined to discuss them in detail.
With the more contagious Delta variant of the coronavirus spreading around the world, including in the United States, Carl Zimmer, who is a science writer and the author of the “Matter” column for The New York Times, spoke to Michael Barbaro on Tuesday’s episode of The Daily.
Although there is not yet good data on how all of the vaccines hold up against Delta, several widely used shots, including those made by Pfizer-BioNTech, are still effective against the Delta variant after two doses, research suggests. Only 47 percent of the United States is fully vaccinated, according to federal data.
We’ll jump to the part where Mr. Barbaro sought clarity about the differing mask guidance from the Centers for Disease Control and Prevention and the World Health Organization.
Here is an excerpt from the conversation:
CARL ZIMMER: Well, they’re making different recommendations looking at the same data, and you have to bear in mind that the W.H.O. is giving advice for the whole world, which is a lot less vaccinated overall than the United States. And even in the United States, the C.D.C. is still saying that you have to wear a mask even if you’re vaccinated in health care settings, on public transportation, and they also recommend that if you’re in a very crowded unventilated place that you wear a mask.
But they’ve been emphasizing, well, these vaccines protect you against Delta, and it is the case that if you’re vaccinated fully, you have good protection against Delta. That’s clear. But with this huge number of people who are still unvaccinated or under vaccinated, public health officials have a tough choice to make. What do they recommend that people do?
MICHAEL BARBARO: Well, I’m not sure if this is a fair question, Carl, but I’m going to ask it anyway, which one of these big public health agencies seems right or maybe righter? Wear masks in this moment to fend off Delta and its potential risks or no, if you’re fully vaccinated, you don’t need to.
CARL ZIMMER: What team am I on? Look, I’m a journalist. I’m not an epidemiologist, OK? So I myself will just keep an eye on rates. In Connecticut, we have very low rates right now, which is great. But if those start to shoot up, if it seems to be Delta is driving it, I might rethink that personally, both to protect myself and to protect others, but I’ll have to play it by ear.
MICHAEL BARBARO: So Carl, if I’m reading between the lines correctly, you are going to allow yourself to perhaps keep walking into a store or a restaurant without a mask following the current guidance in the U.S., but if things change and Delta starts to take off in the community where you live in Connecticut, you might change your behavior, you might become more vigilant. You might be putting that mask back on.
CARL ZIMMER: Well, what I do is based on the most important thing, which is that I am fully vaccinated. And so when anybody is thinking about, “what should I be doing in terms of Delta,” that’s the first thing they should think about. Am I vaccinated? If not, when am I going to get vaccinated?
It should be as soon as possible. Now, putting on a mask when you go indoors someplace, that’s not a big deal. I mean, that’s a pretty straightforward thing to do. We’re not talking about closing down schools and so on.
And so if the state of Connecticut decides that they need to just tell everybody just to put on a mask because it’s too hard to make an honor system work, that’s fine with me. That’s totally fine with me. If that means that fewer people are ending up in the hospital and dying, I’m happy to do my part.
MICHAEL BARBARO: And do you expect, whether it’s Connecticut or New York, or the C.D.C. itself, that kind of guidance might be forthcoming sometime soon based on the transmissibility of Delta?
CARL ZIMMER: I mean, making predictions about this pandemic has been a losing game in a lot of ways. If you’ve been vaccinated, then Delta is not a big risk. But for everybody else, this variant is really dangerous, and so there are going to have to be public health measures that take into account that we have this mixture, where less than half of all Americans are fully vaccinated and really defended against this variant.
And there are some parts of the country, where less than a third are fully vaccinated, and those places are at even greater risk.
MICHAEL BARBARO: So the reality of the coming months, because of Delta, is that those who have gotten vaccinated, tens of millions of Americans, may need to make sacrifices in some regions of the country on behalf of those who have not gone vaccinated?
CARL ZIMMER: It’s a possibility, yes. But that’s what it means to be in a society that values public health. Public health means that we are looking out for each other.