
Senators Roger Wicker, Republican of Mississippi, Angus King, independent of Maine, and John Hickenlooper, Democrat of Colorado, said on Thursday that they had tested positive for the coronavirus, adding to the number of breakthrough cases among lawmakers.
“Senator Wicker is fully vaccinated against Covid-19, is in good health and is being treated by his Tupelo-based physician,” his spokesman, Phillip Waller, said in a statement released by his office, adding that the senator was experiencing only mild symptoms.
The announcement from Mr. Wicker came as his home state has shattered previous records for new cases this week, and is now reporting more new cases relative to its population than any other state in the country. Mississippi is averaging 118 new cases a day for every 100,000 people, according to data compiled by The New York Times.
Mr. King’s statement said he was symptomatic but taking recommended precautions.
“While I am not feeling great, I’m definitely feeling much better than I would have without the vaccine,” he said. “I am taking this diagnosis very seriously, quarantining myself at home and telling the few people I’ve been in contact with to get tested in order to limit any further spread.”
Mr. Hickenlooper said on Twitter that he was experiencing limited symptoms and expressed gratitude to scientists who had developed the vaccine. He also encouraged vaccinated people to get booster shots in accordance with a plan that the Centers for Disease Control and Prevention announced this week.
The Senate is in recess this week after adjourning early last Wednesday, leaving it unclear whether any of the men had been in recent contact with other lawmakers, as well as when or where they were first exposed. Their diagnoses brings to 11 the number of senators who have tested positive so far, according to news reports compiled by Ballotpedia, a political data website; more than 50 members of the House have tested positive.
Several other vaccinated politicians have recently announced breakthrough cases of their own, including Senator Lindsey Graham of South Carolina, who said he tested positive for the virus after attending a gathering hosted by Senator Joe Manchin III of West Virginia.
On Tuesday, Gov. Greg Abbott of Texas tested positive and began receiving an antibody treatment, highlighting both the growing concerns over breakthrough cases in the United States and the political tensions over public health measures that Mr. Abbott has consistently opposed in his home state.
While Mr. Wicker has encouraged his constituents to get vaccinated and has applauded the national vaccination effort in official statements, he has also resisted elements of the Biden administration’s coronavirus response. In June, he introduced a resolution calling on the C.D.C. to end a mask mandate for vaccinated people on public transportation.
As the Delta variant spreads aggressively, infections in vaccinated people have been seen more frequently, though they are still rare. The surge and the rising frequency of breakthrough infections have prompted agencies to extend public health measures. The Transportation Security Administration said on Tuesday that the mask mandate would remain in effect on public transportation through Jan. 18.
Because of an editing error, an earlier version of this item referred incorrectly to John Hickenlooper’s elected office. He is a senator, no longer a governor.

NAIROBI, Kenya — The Africa director at the World Health Organization, Dr. Matshidiso Moeti, criticized the decisions by some wealthy nations to start administering coronavirus booster shots, saying the decisions “make a mockery of vaccine equity” when the African continent is still struggling to get vaccine supplies.
African countries continue to lag far behind other continents in inoculations, with only 2 percent of the continent’s 1.3 billion people fully vaccinated against Covid-19 so far. Though vaccine shipments have accelerated in recent weeks, African nations are still not getting nearly enough to meet their needs, Dr. Moeti said.
Instead of offering additional doses to their already fully vaccinated citizens, she said, rich countries should give priority to poor nations, some of which are being ravaged by the coronavirus pandemic.
“Moves by some countries globally to introduce booster shots threaten the promise of a brighter tomorrow for Africa,” Dr. Moeti said in an online news conference on Thursday. “As some richer countries hoard vaccines, they make a mockery of vaccine equity.”
The World Health Organization has called for a moratorium on booster shots until the end of September to free up vaccine supplies for low-income nations. But several wealthy nations have said they would not wait that long. In the United States, the Biden administration said on Wednesday that it would provide booster shots to most Americans beginning as soon as Sept. 20. France and Germany also said they plan to offer shots to vulnerable populations, and Israel has already given third shots to more than a million residents.
President Biden said in a television interview broadcast on Thursday that he and his wife, Jill Biden, plan to get booster shots themselves, assuming federal regulators give the go-ahead.
Mr. Biden defended offering Americans an additional shot when many countries were struggling to deliver initial doses to their populations.
“We’re providing more to the rest of the world than all the rest of the world combined,” Mr. Biden said in the interview on ABC. “We’re keeping our part of the bargain.”
Africa has so far reported more than 7.3 million cases and 184,000 deaths from the coronavirus, according to the W.H.O. The virus is now surging in about two dozen African nations, pushing many governments to impose lockdowns, extend overnight curfews, close schools and limit public gatherings.
Health experts say the more contagious Delta variant, first detected in India, is responsible for most of the current spread on the continent. “While it took eight months for Alpha to spread to 30 countries, Delta has done so in half that time — only four months,” Dr. Moeti said, comparing Delta to a variant first detected in Britain.
Several African countries are also dealing with outbreaks of other diseases. This week, Ivory Coast confirmed its first Ebola case in almost 30 years. Guinea reported a case of the Marburg virus, the first ever found in West Africa. Uganda, which just emerged from a 42-day coronavirus lockdown, announced a polio outbreak.
Dr. Moeti urged wealthy nations to “rethink the idea of boosters” because of the danger that more dangerous variants will arise as the virus spreads in unvaccinated populations.
“Failure to vaccinate the most at-risk groups in all countries will result in needless deaths,” she said. “We say this every week, and it cannot be repeated enough.”
Michael D. Shear contributed reporting.

New York’s digital vaccine app, the Excelsior Pass, will likely cost far more than originally expected, with projected costs nearing $27 million, according to newly obtained documents shared with The New York Times.
The pass is stepping into the spotlight this week as restaurants, museums, gyms and other indoor venues in New York City are asking customers — often for the first time — to show proof of at least one vaccine dose as part of a new city mandate.
More than three million people have already retrieved an Excelsior Pass, which consists of a QR code that can be stored on a smartphone or printed out, the state said. The app verifies applications against city and state vaccination records, and the code is generated only once someone is considered fully vaccinated, defined as at least 14 days after the final shot.
Through a Freedom of Information Request, the Surveillance Technology Oversight Project, an advocacy group that has expressed concern about the privacy and security implications of vaccine passports, received the latest contract between the state and I.B.M., which is developing the app.
In June, the advocacy group provided The Times with the original version of the contract between the state and I.B.M., which estimated the total cost of the project would be $17 million over three years. Even that was far more than the $2.5 million in development costs that Mr. Cuomo and his staff had publicly mentioned when announcing the arrival of the nation’s first government-sponsored digital app that verifies proof of vaccination.
The updated version of the contract, signed by the state’s Office of Information Technology Services in late June, adds another $10 million. New York, the contract states, had already incurred an extra $656,421 in charges for technical support and updates. And a Phase 2 of the project, which was mentioned but not described in detail in the original contract, ended up costing more than double than estimated, rising to $4.7 million from $2.2 million.
“We always said that Excelsior Pass would be a high-tech distraction from real public health measures, but we had no idea the price would go up this high,” said Albert Fox Cahn, the executive director of the Surveillance Technology Oversight Project. “Even as New Yorkers find themselves on the hook for millions more, the app still isn’t able to do a lot of the basics.”
The governor’s office did not immediately return a request for comment about the contract.
The contract lists some of the issues that software engineers were called in to fix, such as incorrect error messages and crashes. Engineers added foreign language capability, access for the visually impaired and, to address a common problem, made it so the phone number entered by a user does not need to match what is listed in the vaccine registries. The fixes are ongoing. Not until June, the contract indicates, did the app make it possible for someone who has periods in their name (like T.J.) to retrieve a pass.
Some users are still having trouble finding their passes, sometimes because the registries have outdated information listed, like an old ZIP code. In order to find a person’s vaccination record, the app checks his or her name, date of birth, ZIP code and county of vaccination against the vaccine registry, and nearly all information must match. Some 4 percent of users who tried to get passes in the app’s opening months were unable to, the state said.
Phase 2 of the contract included the development of what the state has called Excelsior Pass Plus, which launched on Aug. 4. The main enhancement of the Plus pass is that it now includes the date, place and type of vaccination in the QR code, instead of just verifying that a person is vaccinated. That information will be shared when the app is scanned, but it allows for a wider range of places to use it as vaccination proof.
American Airlines is accepting the pass for travel to some international destinations. Both the original and the Plus pass also allow users to show results of P.C.R. and antigen tests, the state said.
For now, the Excelsior Pass is available for New Yorkers vaccinated in state, and New Yorkers vaccinated out of state who ask their health care providers to upload that information to the New York vaccine registries. But that may be about to change.
The contract also lays out a new, previously undisclosed Phase 3, which is projected to cost $6.7 million. By this summer, the contract states, the app was expected to begin including data from New Jersey and Vermont, which presumably means more people vaccinated in those states would be able to get passes. And the app is scheduled to add the ability to track third doses, just in time for booster shots, assuming federal regulators authorize them.

The United States has requested that the United Nations scale back the annual General Assembly meeting in New York next month, making it a mostly virtual gathering, to avoid the “superspreader” infection risks posed by the pandemic’s highly contagious Delta variant.
The request, made in a diplomatic note sent by the U.S. Mission to the other members of the global organization, appeared to assure that the world’s biggest diplomatic gathering would be similar to the mostly virtual one held in 2020, or perhaps be even more restricted.
The General Assembly meeting, which starts in mid-September, historically has been one of the busiest events at the United Nations headquarters, with heads of state and government from around the world converging in New York with their diplomatic entourages. The influx of V.I.P.’s creates enormous security challenges for the New York Police Department and routinely paralyzes traffic in Manhattan.
Though the United States is the host country, it does not dictate which foreign leaders visit the United Nations to address the General Assembly in what is known as the General Debate. But the organization defers to the host government authorities on matters of health requirements.
U.N. officials said earlier in the summer that the session in September, the 76th General Assembly, would be much more like the prepandemic version, with at least some foreign leaders attending the General Debate in person and many side events, conferences and social gatherings held face to face.
But as the risks posed by the rapidly spreading Delta variant have grown — even to people who have been fully vaccinated — the United States government has turned more cautious.
“The United States, as the host country of the U.N. Headquarters, bears a significant responsibility and we need your support to prevent UNGA 76 High-Level Week from being a superspreader event,” said the U.S. Mission’s diplomatic note, which was seen by The New York Times.
‘In light of current health concerns, heads of delegation should consider delivering their statements to the U. N. General Assembly’s General Debate by video,” the note said.
The note acknowledged that U.N. officials had put precautions in place including mandatory use of face masks and social distancing, and had given the leaders of all 193 members the option of delivering speeches by prerecorded video.
Nonetheless, the note said, “the United States needs to make clear our call, as the host country, for all U.N.-hosted meetings and side events, beyond the General Debate, to be fully virtual.”
It further recommended that the United Nations strengthen what has been an honor system for visitors to declare themselves virus free, saying the organization should require “confirmed negative Covid-19 status to enter U. N. Headquarters, and, if possible, vaccination.”
Should countries wish to send delegations next month, the note said, the United States requested that they be reduced to “the minimum number of travelers necessary.”
It remained unclear on Thursday whether President Biden would make his first General Assembly speech in person. Officials at the U.S. Mission said they had no information on Mr. Biden’s plans.

Covid precautions have turned many parts of our world into a giant salad bar, with plastic barriers separating sales clerks from shoppers, dividing customers at nail salons and shielding students from their classmates.
Intuition tells us a plastic shield would be protective against germs. But scientists who study aerosols, air flow and ventilation say that much of the time, the barriers don’t help and probably give people a false sense of security. And sometimes the barriers can make things worse.
Research suggests that in some instances, a barrier protecting a clerk behind a checkout counter may redirect the germs to another worker or customer. Rows of clear plastic shields, like those you might find in a nail salon or classroom, can also impede normal air flow and ventilation.
Under normal conditions in stores, classrooms and offices, exhaled breath particles disperse, carried by air currents and, depending on the ventilation system, are replaced by fresh air roughly every 15 to 30 minutes. But erecting plastic barriers can change air flow in a room, disrupt normal ventilation and create “dead zones,” where viral aerosol particles can build up and become highly concentrated.
“If you have a forest of barriers in a classroom, it’s going to interfere with proper ventilation of that room,” said Linsey Marr, professor of civil and environmental engineering at Virginia Tech and one of the world’s leading experts on viral transmission. “Everybody’s aerosols are going to be trapped and stuck there and building up, and they will end up spreading beyond your own desk.”

All of the vaccines authorized in the United States provide strong protection against severe disease and death from Covid-19.
But the federal government’s recent booster recommendation was based on data suggesting that the protection provided by the Pfizer-BioNTech and Moderna vaccines against infection and mild disease has been waning over time, officials said on Wednesday.
“Even though this new data affirms that vaccine protection remains high against the worst outcomes of Covid,” Dr. Murthy said at the briefing, “we are concerned that this pattern of decline we are seeing will continue in the months ahead, which could lead to reduced protection against severe disease, hospitalization and death.”
But less data is available on the Johnson & Johnson vaccine, which was not authorized until the end of February, two months after Pfizer-BioNTech and Moderna, the mRNA vaccines. (The Johnson & Johnson vaccine uses a modified adenovirus to deliver its instructions to human cells.) In addition, Johnson & Johnson vaccinations were temporarily paused while health officials investigated reports that a very small number of people had developed a rare blood-clotting condition after receiving the vaccine.
More than 150 million Americans have gotten mRNA vaccines, far exceeding the 14 million who have received the Johnson & Johnson shot, according to data from the Centers for Disease Control and Prevention.
Without robust data on the long-term effectiveness of the Johnson & Johnson vaccine, it is hard for health officials to recommend boosters, said John Moore, a virologist at Weill Cornell Medicine. “If you’re doing data-driven decisions and you don’t have the data, what can you do?” he said. “This is sort of the dilemma. Public confidence in vaccines generally depends on seeing how the sausage is made, seeing that it is a data-driven, transparent process.”

Cuba’s health care system, long a source of national pride, is in acute distress, particularly in distant provinces.
After fending off the coronavirus last year, Cuba has been ravaged this summer by the highly contagious Delta variant, which has sent case rates soaring and swamped the country’s medical system.
More than 8,600 new cases were reported on Tuesday, about six times as many as the number of new cases just two months ago, according to Ministry of Health figures.
Oxygen supplies for Covid-19 patients are running low, and the factory that produces the nation’s canisters is currently shut down.
Mortuaries and crematories have been overwhelmed. The city of Guantánamo, for example, is dealing with a surge of deaths that on some days climbs to about eight times the usual number, a government official said. Cubans are posting heart-wrenching videos of dead relatives, saying that their loved ones died for lack of medical care.
This past weekend, after Cuba’s prime minister, Manuel Marrero Cruz, said that Cubans were complaining more about doctors and their poor service than they were about the shortages, nearly two dozen young physicians and medical students took to social media to state, one by one: “I am publicly declaring that doctors are not to blame for the collapse of the public health system.”
The move was a daring step in Cuba, where any public show of discontent may result in the loss of employment or even prison.
Cuba’s president, Miguel Díaz-Canel Bermúdez, acknowledged recently that the pandemic had “exceeded the capacity” of the Cuban health care system, but he blamed the U.S. trade embargo for the shortages the country suffers.
While the pandemic has strained medical systems around the world, the calamity in Cuba is particularly significant because the government has for decades held its free health care system up as a signal accomplishment of the socialist revolution. But the growing crisis has revealed a frayed system that, while often producing medical breakthroughs, is also denounced as ill-equipped and underfunded.
The Cuban Ministry of Health did not respond to several requests for comment.
Alexander J. Figueredo Izaguirre, a doctor in the Cuban province of Granma, said he was fired this year after he criticized the poor state of the country’s hospitals following the death of his grandfather.
“The funeral homes can’t cope, the hospitals can’t cope, the clinics can’t cope,” he said. “We have been struggling for a year and a half in this battle against this disease — without weapons — when hundreds and thousands of people are dying.”

Paralympic officials in Tokyo on Thursday reported the first confirmed coronavirus case in the Olympic Village, five days before the Games are set to open.
The Olympic Village case is one of 16 total associated with the Paralympics so far.
The early Paralympic cases come as both Japan and Tokyo, the capital, are reporting record daily new cases. On Tuesday, the Japanese government extended the state of emergency in Tokyo and other regions until Sept. 12, a week after the end of the Paralympic Games. It also declared an emergency in seven more prefectures.
During the Olympic Games, which lasted from July 23 to Aug. 8, organizers recorded more than 500 cases within the so-called Olympic bubble. Only three of those people were admitted to the hospital, and no severe cases arose among those directly connected to the Olympics. Visitors from overseas were asked to travel only between their hotels and competition venues for their first 14 days in Japan, and athletes and others were tested daily. Those who tested positive were put into isolation and some athletes were even sidelined after a positive test. Paralympic athletes are expected to be under similar restrictions.
Just as with the Olympics, the Paralympics will allow almost no spectators, although the Tokyo organizers have said that they hope to admit limited numbers of students to some events. At a news conference this week, Seiko Hashimoto, president of the Tokyo organizing committee, said that organizers were implementing “watertight measures” to avoid large outbreaks.

Massachusetts Governor Charlie Baker, a Republican in a deeply blue state who has so far resisted issuing a mask mandate or vaccination requirement for schools, came under pressure this week for stricter regulations from the state’s largest teachers’ union.
The Massachusetts Teachers Association board of directors voted on Tuesday, 46 to 4, to adopt a vaccine requirement for all eligible students and staff, following up on a unanimous vote August 1 in favor of a mask mandate. The union’s president, Merrie Najimy, noted that Governor Baker has resisted taking these steps.
“Educators and our unions are doing everything in our power to ensure that public schools and colleges can open safely,” she said. “We continue to be alarmed by the failure of state political leaders to follow our example.”
She added, “it’s as if Governor Baker” and other state education officials “have learned nothing over the past year and a half.”
Governor Baker is facing a drumbeat of pressure on masking requirements; some of his fellow Republican governors in conservative states like Texas, Florida and Arizona have put up far stronger resistance, by issuing bans on mask and vaccine mandates.
Polling suggests strong support for a school mask mandate in the state, with 81 percent of Massachusetts voters in favor of the idea, and just 12 percent opposing it, according a survey released Thursday by The MassINC Polling Group.
Governor Baker, a Republican, has said he prefers to leave masking decisions to local officials, who “know these communities best.”
“Different communities are in different places,” he told WGBH, a radio station. “You have some communities in Massachusetts where 85 to 95 percent of all the kids and the middle and high school are vaccinated. You have many other districts in Massachusetts where the numbers are far, far smaller.”
On Thursday afternoon, however, Governor Baker announced a strict vaccine mandate for 42,000 state government workers, requiring them to show proof of vaccination by mid-October.

There wasn’t a single I.C.U. bed available in Alabama on Wednesday, a possible sign of what other states may confront soon amid a deadly surge of new infections in parts of the United States with low vaccination rates.
I.C.U. beds, where hospitals’ critically ill patients are treated, are filling up across Southern states, and Alabama is one of the first to run out. The Alabama Hospital Association said on Wednesday night that there were “negative 29” I.C.U. beds available in the state, meaning there were more than two dozen people being forced to wait in emergency rooms for an open I.C.U. bed.
The situation has grown desperate in Alabama, one of several states reporting a wave of cases driven by the highly contagious Delta variant and low vaccination rates.
In the week ending Aug. 12, one in five American I.C.U.s had reached or exceeded 95 percent of beds full. The crisis is concentrated in the South, with small pockets of high occupancy elsewhere in the country. The national average I.C.U. occupancy in 2010 was 67 percent, according to the Society of Critical Care Medicine, though the occupancy baseline changes depending on the place, time of year and size of hospital.
During other surges across the country, hospitals have been forced to improvise, expanding capacity by creating new I.C.U.s in areas normally used for other purposes, like cardiac or neurological care, and even hallways or spare rooms. Experts say maintaining existing standards of care for the sickest patients may be difficult or impossible at hospitals with more than 95 percent I.C.U. occupancy.
Alabama has never before faced this sort of I.C.U. crisis during the pandemic, the state health officer, Dr. Scott Harris, said on Wednesday in a television interview with WSFA12 News. Such patients are still being treated elsewhere in hospitals, including in “perhaps a regular room on a floor that’s been converted into an I.C.U.,” he said.
But the strain on hospitals threatens to overwhelm staff already stretched thin and endanger the quality of care for non-Covid patients, he said.
“In most parts of the state, the average person who has a heart attack today or is involved in a serious automobile accident, it’s going to be difficult,” Dr. Harris said. “The hospitals are going to have to be real creative in finding a place to be able to care for that patient.”
Last week, at least two hospitals in Houston were so overwhelmed with virus patients that officials erected overflow tents outside. Elsewhere in Texas, in Austin, hospitals were nearly out of beds in their intensive care units. And in San Antonio, cases reached levels not seen in months, with children as young as 2 months old tethered to supplemental oxygen.
Arkansas hospitals were also close to capacity.
Only 47 percent of people in Alabama are at least partially vaccinated, far lower than the national rate of 60 percent, according to a New York Times database.
On Monday, the seven-day hospitalization average hit 2,603, up from a low of 252 on June 26. Only January’s numbers were higher, when the seven-day average peaked at more than 3,300 on Jan. 10.
Gov. Kay Ivey of Alabama said last month that the surge in new cases was attributable to the large number of people who remain unvaccinated. On Friday, she reinstated Alabama’s state of emergency, which had expired in early July, in an effort to expand hospital capacity.
Dan Levin contributed reporting.