The staff of a Southern California hospital system experienced a small resurgence in coronavirus infections this summer, despite more than four-fifths of its employees being fully vaccinated.The findings join a flurry of recent reports of so-called breakthrough infections among vaccinated people. Earlier this summer, Provincetown, Mass., reported a Covid outbreak among many vaccinated residents, and the Centers for Disease Control and Prevention has confirmed that these cases are happening more often with the highly contagious Delta variant of the virus than they did with previous versions.Breakthrough infections tend to be mild, and vaccines are still highly effective against severe disease and death from the Delta variant. Still, studies on breakthrough infections have fueled the debate over the need for a booster dose, which the Biden administration has supported, as well as masking requirements aimed at preventing the spread of Delta.Even among its fully vaccinated workers, the University of California San Diego Health witnessed a significant increase in infections from June to July, according to a letter published Wednesday in the New England Journal of Medicine.From March through July, a total of 227 workers tested positive, according to the letter. Of those, 130 — or 57 percent — were vaccinated.The total number of symptomatic Covid-19 cases went up more than eightfold, from 15 in June to 125 in July, with 75 percent of the cases occurring in fully vaccinated employees.There were no reported deaths, and one unvaccinated person was hospitalized, according to the researchers.While the number of cases represented a tiny fraction of University of California San Diego Health’s overall work force of 19,000, the growing number of infections points to a noteworthy drop in the effectiveness of the vaccines, according to the authors.“Our data suggest that vaccine effectiveness against any symptomatic disease is considerably lower against the delta variant and may wane over time since vaccination,” they wrote.Given these findings, they recommended a rapid return to indoor masking and intensive testing strategies to detect the virus.

Many Americans felt socially isolated during the pandemic, cut off from friends and family as they hunkered down and kept their distance to try to protect themselves from infection.But new research released Thursday suggests many people’s sense of isolation increased even as the public health crisis in the United States began to abate, with communities opening up and the economy improving.While the level of social isolation declined during the spring of the pandemic after the initial shock of the crisis subsided, it then increased sharply over the summer months last year, according to researchers at Harvard, Northeastern, Northwestern and Rutgers universities, before leveling off during the fall.People began to feel less disconnected last December through April of this year, but the levels of social isolation measured by the researchers increased again this June.The findings suggest recovery from the pandemic may take a long time and could affect people’s view of their relationships over time. “There were cumulative effects from the social isolation,” said David Lazer, a professor of political science and computer sciences at Northeastern and one of the study authors.To determine social isolation, the researchers asked each person about the number of people they could count on to care for them if they got sick, to lend them money, to talk to about a problem if they were depressed, or to help them find a job. Someone who said they had only one person, or no one they could turn to, in a given category was considered socially isolated.The researchers polled a total of 185,223 individuals over 12 different surveys from April 2020 to June 2021.Even now, with many more people vaccinated against the coronavirus and much more actively engaged in their communities, people may be thinking differently about those they previously relied on for help. “That pause in life may be causing a lot of revisitation in our relationships,” said Dr. Lazer, who pointed to the unusual number of people deciding to leave their jobs as the pandemic ends. “It takes a while to heal the social fabric.”The increase in feelings of isolation even when the most severe restrictions were lifted “is striking,” said Mario L. Small, a professor of sociology at Harvard who was not involved in the study. People may have felt they had fewer people to lean on because they remained physically distant from a broad network of acquaintances and friends, he said, even when the lockdowns had eased.The researchers found people’s isolation increased last summer even though they were seeing people more. “Our findings show that recovering from social isolation is hard and does not simply stem from increased social contact,” the researchers concluded.The researchers also point to a strong association between social isolation, particularly for those people who said they lacked people they could turn to for emotional support, and moderate or severe depression.Many of those hardest hit by the pandemic, with lower incomes and less education, seem slower to improve, Dr. Lazer said. “We definitely do see a separation of fates in respect to socioeconomic status,” he said, with some groups experiencing a longer and more uneven recovery.

The Covid-19 death toll in Brazil has now surpassed 500,000, behind only the United States, which marked 600,000 deaths last week, and India, where deaths may range from 600,000 to as high as 4.2 million.Nearly 18 million people have been infected so far, and the country is averaging almost 73,000 new cases and some 2,000 deaths a day, according to official data. But many experts believe the numbers understate the true scope of the country’s epidemic, as they do in India.Brazil’s president, Jair Bolsonaro, has been heavily criticized for dismissing the threat posed by the virus, despite contracting it himself last year. On Saturday, thousands of people protested his response to the pandemic, including his resistance to mask-wearing edicts and the slow rollout of vaccines, according to Reuters. Only 11 percent of residents are believed to be fully vaccinated.A severe drought has also gripped the country, the worst in at least 91 years, and experts say a terrible fire season may further complicate the country’s struggle to manage the virus. The smoke could even aggravate cases of Covid-19, by increasing the inflammation in the lungs.“It’s a situation that’s dangerous,” said Dr. Aljerry Rêgo, a professor and director of a Covid facility in the Amazon state of Amapá. “And the biggest risk, of course, is overwhelming the public health system even further, which is already precarious in the Amazon.”In recent testimony before a legislative committee, Brazil’s former health ministers described Mr. Bolsonaro’s befuddling belief that an anti-malaria drug was effective against Covid-19, and an executive at Pfizer said that the company offered millions of doses of its Covid-19 vaccine to Brazil last year — but received no response from the government for months.Mr. Bolsonaro shrugged off the revelations. Last month, his government announced that Brazil would host the Copa America soccer tournament later this year, after Argentina decided it would be irresponsible to do so while the virus continued to spread.On Friday, officials reported that 82 people connected with the tournament had contracted Covid-19, according to The Associated Press. Brazil’s health ministry said in a statement that 37 players and staffers of the 10 tournament teams infected, along with 45 workers.Coronavirus World Map: Tracking the Global OutbreakThe virus has infected and killed millions of people around the world. See detailed maps and charts for each country.

Even with vaccines, many older people and their relatives are weighing how to manage at-home care for those who can no longer live independently.At 86, Diane Nixon, living in an apartment at the back of a daughter’s house, no longer drives and has trouble getting around.When her health worsened last year before the coronavirus pandemic, she and all four of her daughters talked about whether a nursing home would be the next step. She worried that she had become a burden to her children.“She was very adamant about not wanting her daughters to be caregivers,” said Jill Cooper, one of her daughters, who lives nearby in the Pittsburgh area.But as infections began to tear through nursing homes across the country, killing tens of thousands of residents last year, Ms. Nixon and her family realized a group home was no longer a viable choice. Especially after most of them barred visitors to help contain outbreaks.“Not to be able to see her was not an option for us,” Ms. Cooper said, so the family contacted a local home health agency to hire someone to help her during the day.“It made us look at an alternative that we might not have looked at as hard,” she said.The pandemic’s toll on nursing homes drove occupancy down significantly — not just from the 132,000 deaths but also because of a decline in admissions. The 14,000 skilled nursing facilities in the United States now have on average a vacancy rate of slightly more than 25 percent, according to figures from the National Investment Center for Seniors Housing & Care.But as immunization campaigns inside them began taking priority in the winter this year, with nearly three million residents and staff members fully vaccinated, the outlook improved somewhat. Nursing homes point to the steep decrease in Covid-related deaths, saying they have dropped by 91 percent since December.While the industry has received $21 billion in federal funding under the CARES Act as part of congressional efforts to help health care facilities during the pandemic, nursing homes are lobbying for more federal aid to cover the higher cost of personal protective equipment, testing and staffing at their facilities. They say that they are losing tens of billions of dollars in revenue because of the pandemic and that many homes are at risk of closing.But the deaths of so many elderly residents, captive in those homes, has deepened levels of anxiety and guilt among many families planning the next phase of care for an aging relative. Experts say rethinking the purpose of nursing homes is long overdue.Even before the pandemic began 14 months ago, nursing homes had become the source for rampant, antibiotic-resistant infections. The facilities also faced systemic problems like high turnover among nursing home staff and the gaming of the federal government’s rating system, which made it hard for families to judge the quality of homes.For years, federal health officials and some insurers have tried to encourage more stay-at-home care, and the pandemic has created a sense of urgency.“It’s really changed the paradigm on how older adults want to live,” said Dr. Sarita Mohanty, the chief executive of the SCAN Foundation, a nonprofit group focused on issues facing older adults. The vast majority of those adults would prefer to stay at home as they age, she said.“What’s happened is a welcome sort of market correction for nursing homes,” said Tony Chicotel, a staff attorney for California Advocates for Nursing Home Reform in San Francisco. Some families, he said, “ended up agreeing to a nursing home without giving it a lot of deliberation.” But after trying home care during the pandemic, many families found keeping an older relative at home was a viable alternative, he said.Nursing homes rose from the almshouses in England and America that cared for the poor. In the United States, passage of the Social Security Act in 1935 provided money for states to care for the elderly. Thirty years later, the Medicaid program expanded funding, making long-term care homes central to elder care, said Terry Fulmer, the president of the John A. Hartford Foundation, an advocacy group for older adults. “If you pay the nursing homes, that’s where you go,” Dr. Fulmer said.It wasn’t until the 1970s that some programs began to pay for home care, and the number of nursing home residents nationwide started to slowly decline, with occupancy levels in recent years flattened to about 80 percent, according to data from the Kaiser Family Foundation.New technology makes it easier to monitor someone at home, said Dr. Fulmer, who thinks the pandemic might be a “tipping point.”Heidi Dolan, left, and Jill Cooper, Ms. Nixon’s daughters. They have not ruled out eventually placing Ms. Nixon in a nursing home. “We’re continuing the journey,” Ms. Cooper said.Kristian Thacker for The New York TimesBeth Kreisman, a nurse who works at Debra D. Feldman & Associates in Buffalo Grove, Ill., helping families navigate these issues, faced the same dilemma with her stepmother, now 89. Her stepmother had been showing signs of dementia, and a hospital stay last spring “took a lot out of her,” Ms. Kreisman said.“She couldn’t go home by herself,” she said. “We were really in a quandary if she should go to skilled nursing or go home with a caregiver.”But concern about her contracting the virus at a facility persuaded the family to opt for home care. “We were absolutely convinced that if she got Covid, she would die,” Ms. Kreisman said.Now that her stepmother is vaccinated, the family has renewed discussions about whether she would be best served in a nursing home. Her stepmother doesn’t want to leave the home where she spent decades with Ms. Kreisman’s late father. “In her mind, if she moves out of her place, then she is leaving my dad,” she said.“We’ve decided for the time being to keep her home,” she said. Many of her clients are also choosing home care in lieu of a nursing home.“I think people are going to be more cautious and ask more questions before they place a loved one in a nursing home or choose one to go to themselves,” said Lori O. Smetanka, the executive director for the National Consumer Voice for Quality Long-Term Care, a nonprofit group. “People are still worried, to some extent, about their safety.”While the availability of a Covid vaccine has lessened the risk of a resident becoming ill, some residents and staff members are refusing to be vaccinated, making the environment still potentially dangerous. In Kentucky, an unvaccinated worker recently set off an outbreak, according to a study released last month by the Centers for Disease Control and Prevention.And some individuals may not need nursing home care. Debra Feldman, the founder of the Chicago agency, said she made the decision to have one client with dementia leave the facility where she was recovering from surgery for a broken hip because of the coronavirus restrictions imposed last spring.“It was really nice outside. She was being shut in her room, and she couldn’t understand what was going on,” said Ms. Feldman, who said her client was becoming increasingly agitated. The nursing home would not allow her to go outside on the patio.The woman, in her mid-80s, recovered well at home. “Now she’s walking without a walker,” Ms. Feldman said. “She is pretty solid on her feet.”The backyard of Ms. Dolan’s home, where Ms. Nixon has an apartment adjoining an outdoor sitting area.Kristian Thacker for The New York TimesBut many people don’t have a choice because of their financial situation or physical needs. “There’s limited wiggle room in avoiding nursing home care,” said Richard Mollot, the executive director of the Long Term Care Community Coalition, a nonprofit group in New York. “You’re not given a lot of time and choices when you leave the hospital,” he said.And many families know circumstances can change. Ms. Nixon’s family has not ruled out some day having her move into a nursing home. “We’re continuing the journey,” Ms. Cooper said, emphasizing that they still viewed long-term nursing homes positively.Home care costs can be prohibitive. If a person is reliant on Medicaid, the federal-state program, what services are available within the community or at home vary widely, depending on the individual state. In some places, paid home care is capped. “We are already seeing that people with low incomes have fewer choices because of the way the system is structured,” Ms. Smetanka said.The Biden administration has proposed spending $400 billion to address some of the gaps in long-term care by providing more funding under Medicaid for these alternatives, but prospects for President Biden’s $2 trillion package are unclear.In some areas of the country, staff shortages may also limit the available options, said Liz Barlowe, the former president of the Aging Life Care Association, a nonprofit representing senior care professionals. Even with seemingly low occupancy rates, nursing homes may be slow to accept new long-term residents because they do not have enough staffing, and home health agencies have difficulty finding enough aides if people need round-the-clock care. “That is a huge challenge, not only for facilities but also home care,” said Ms. Barlowe, who advises families in Seminole, Fla.Still, she says she has sensed a shift in views on long-term care among families, even as some of the worst of the experiences in nursing homes fade.The crisis laid bare how poorly equipped many facilities were to handle a pandemic, she said. It also underscored that the industry needs to make fundamental changes to restore the confidence of the country.“The damage is done,” Ms. Barlowe said. “Now we all know it can happen. We need to be looking at system change.”

A multistate group of anesthesiologists filed cases in Texas and Colorado, accusing the insurance giant of squeezing them like a “boa constrictor.”UnitedHealthcare, one of the nation’s largest health insurers, is being sued in two states by a large group of anesthesiologists who are accusing the company of stifling competition by forcing the doctors out of its network and by using its enormous clout to pressure hospitals and surgeons to stop referring patients to them.The lawsuits, filed Wednesday in Colorado and Texas, were brought by U.S. Anesthesia Partners, a sizable physician-owned practice backed by private-equity investors. The practice claims in the Texas lawsuit that United engaged in “unlawful tactics and pressure campaigns,” including “bribing” surgeons with contracts that paid them much more if they steered patients away from the group’s anesthesiologists.The doctors make similar claims in the lawsuit they filed in Colorado, where they say United orchestrated a “group boycott.” They describe United as “like a boa constrictor,” squeezing the group “from all angles.”In an emailed statement, United said the lawsuits were “just the latest example of the group’s efforts to pressure us into agreeing to its rate demands and to distract from the real reason that it no longer participates in our network.” The company said it had not yet been served with either complaint.United added that many of the private-equity-backed physician groups “expect to be paid double or even triple the median rate we pay other physicians providing the same services,” driving up the cost of care. The company says these groups have been using their increasing presence in a given regional market to demand higher rates. It says that its goal has been to keep the groups in network but that it is rethinking its approach.While insurers and the hospitals and doctors have long had ugly standoffs during contract negotiations, the parties typically come to a last-minute agreement. But United has become increasingly aggressive in its stance toward large physician groups like U.S. Anesthesia, dropping a number of them from its network, according to analysts.“United has a lot of market power and they want to use it to their advantage,” said Dean Ungar, who follows the insurance behemoth for Moody’s Investors Service, which evaluates the company’s debt. “They are willing to play hardball with some of these companies.”U.S. Anesthesia, which operates in nine states, said it had a long relationship with United and was part of the carrier’s networks in Texas and Colorado until last year.But the doctors also raise questions about the insurer’s potential conflicts of interest as its parent company, UnitedHealth Group, also offers medical services. UnitedHealth, which had $257 billion in sales last year, has become a sprawling conglomerate that includes more than 50,000 physicians, a chain of surgery centers, a pharmacy benefit manager and other assorted health care businesses in addition to its traditional insurance business.UnitedHealth directly competes with U.S. Anesthesia, according to the Texas lawsuit, through an ownership interest in Sound Physicians, a large medical practice that provides emergency and anesthesiology services. Sound Physicians is looking to expand in markets like Fort Worth and Houston, and U.S. Anesthesia claims in the lawsuit that its doctors were contacted by Sound Physicians “to induce them to leave” and challenge the noncompete provisions in their contracts to work with the United group.The major insurer throws its weight around in other ways, the lawsuit claims. While the company’s Optum unit, which operates the surgery centers and clinics, is technically separate from the health insurer, the doctors accuse United of forcing its OptumCare facilities to sever their relationships with the anesthesiology group and pushing in-network surgeons to move their operations to hospitals or facilities that do not have contracts with U.S. Anesthesia.“United and its affiliates have extended their tentacles into virtually every aspect of health care, allowing United to squeeze, choke and crush any market participant that stands in the way of United’s increased profits,” the doctors claim in their lawsuit.It is standard practice, United said, for an insurer to encourage the use of hospitals and doctors within its network.In contrast to many smaller physician groups that are struggling because of the pandemic, United has maintained a strong financial position, shoring up profits while elective surgeries and other procedures were shut down, resulting in fewer medical claims. So it has continued to expand, hiring more doctors and buying up additional practices. The company says it plans to add more than 10,000 employed or affiliated doctors this year.The relationship between insurers and providers has become more complicated as more insurance carriers own doctors’ groups or clinics. “They want to be the referee and play on the other team,” said Michael Turpin, a former United executive who is now an executive vice president at USI, an insurance brokerage.Employers that rely on UnitedHealthcare to cover their workers have a difficult time judging who benefits when insurers fail to reach an agreement to keep a provider in network. “This is just as much about profit as it is about principle,” Mr. Turpin said.United has defended its actions in the past by pointing to the role many of these doctors’ groups, financed by private equity, played in creating surprise medical bills that overwhelmed and burdened Americans around the country. Because the groups’ doctors specialize in areas like emergency care or anesthesia, patients are often shocked to find out that they are not in network even if the hospital where they received care is.Some of the doctors’ groups, like Envision Healthcare, whose doctors provide emergency-room care, pursued a strategy of keeping their doctors out of network to make more money. Patients were caught in the middle as insurers and doctors fought over out-of-network bills, and many people ended up owing large sums not covered by their health plans.When criticism of these tactics pressured Congress to consider remedies, the private-equity firms backing groups like Envision and TeamHealth spent large sums trying to block federal legislation. Lawmakers finally took action at the end of last year to protect patients from surprise bills by requiring parties to reach a fair price.But doctors say United is increasingly unwilling to come to an agreement they can accept. Envision, which eventually agreed to lower its payments and be included in the health plan’s network, said United dropped it this year because it would not agree to “drastic cuts to clinician pay.”“United turned down multiple proposals that would reduce the total cost of care for patients,” Envision said in an emailed statement. “We are left to wonder why it appears United does not want our 25,000 clinicians in their network.”The insurer has also dropped other groups. Last year, Mednax, which employed specialists in neonatology and anesthesiology, announced it had been dropped by United in four states. The company has since sold both its radiology and anesthesiology practices.

A multistate group of anesthesiologists filed cases in Texas and Colorado, accusing the insurance giant of squeezing them like a “boa constrictor.”UnitedHealthcare, one of the nation’s largest health insurers, is being sued in two states by a large group of anesthesiologists who are accusing the company of stifling competition by forcing the doctors out of its network and by using its enormous clout to pressure hospitals and surgeons to stop referring patients to them.The lawsuits, filed Wednesday in Colorado and Texas, were brought by U.S. Anesthesia Partners, a sizable physician-owned practice backed by private-equity investors. The practice claims in the Texas lawsuit that United engaged in “unlawful tactics and pressure campaigns,” including “bribing” surgeons with contracts that paid them much more if they steered patients away from the group’s anesthesiologists.The doctors make similar claims in the lawsuit they filed in Colorado, where they say United orchestrated a “group boycott.” They describe United as “like a boa constrictor,” squeezing the group “from all angles.”In an emailed statement, United said the lawsuits were “just the latest example of the group’s efforts to pressure us into agreeing to its rate demands and to distract from the real reason that it no longer participates in our network.” The company said it had not yet been served with either complaint.United added that many of the private-equity-backed physician groups “expect to be paid double or even triple the median rate we pay other physicians providing the same services,” driving up the cost of care. The company says these groups have been using their increasing presence in a given regional market to demand higher rates. It says that its goal has been to keep the groups in network but that it is rethinking its approach.While insurers and the hospitals and doctors have long had ugly standoffs during contract negotiations, the parties typically come to a last-minute agreement. But United has become increasingly aggressive in its stance toward large physician groups like U.S. Anesthesia, dropping a number of them from its network, according to analysts.“United has a lot of market power and they want to use it to their advantage,” said Dean Ungar, who follows the insurance behemoth for Moody’s Investors Service, which evaluates the company’s debt. “They are willing to play hardball with some of these companies.”U.S. Anesthesia, which operates in nine states, said it had a long relationship with United and was part of the carrier’s networks in Texas and Colorado until last year.But the doctors also raise questions about the insurer’s potential conflicts of interest as its parent company, UnitedHealth Group, also offers medical services. UnitedHealth, which had $257 billion in sales last year, has become a sprawling conglomerate that includes more than 50,000 physicians, a chain of surgery centers, a pharmacy benefit manager and other assorted health care businesses in addition to its traditional insurance business.UnitedHealth directly competes with U.S. Anesthesia, according to the Texas lawsuit, through an ownership interest in Sound Physicians, a large medical practice that provides emergency and anesthesiology services. Sound Physicians is looking to expand in markets like Fort Worth and Houston, and U.S. Anesthesia claims in the lawsuit that its doctors were contacted by Sound Physicians “to induce them to leave” and challenge the noncompete provisions in their contracts to work with the United group.The major insurer throws its weight around in other ways, the lawsuit claims. While the company’s Optum unit, which operates the surgery centers and clinics, is technically separate from the health insurer, the doctors accuse United of forcing its OptumCare facilities to sever their relationships with the anesthesiology group and pushing in-network surgeons to move their operations to hospitals or facilities that do not have contracts with U.S. Anesthesia.“United and its affiliates have extended their tentacles into virtually every aspect of health care, allowing United to squeeze, choke and crush any market participant that stands in the way of United’s increased profits,” the doctors claim in their lawsuit.It is standard practice, United said, for an insurer to encourage the use of hospitals and doctors within its network.In contrast to many smaller physician groups that are struggling because of the pandemic, United has maintained a strong financial position, shoring up profits while elective surgeries and other procedures were shut down, resulting in fewer medical claims. So it has continued to expand, hiring more doctors and buying up additional practices. The company says it plans to add more than 10,000 employed or affiliated doctors this year.The relationship between insurers and providers has become more complicated as more insurance carriers own doctors’ groups or clinics. “They want to be the referee and play on the other team,” said Michael Turpin, a former United executive who is now an executive vice president at USI, an insurance brokerage.Employers that rely on UnitedHealthcare to cover their workers have a difficult time judging who benefits when insurers fail to reach an agreement to keep a provider in network. “This is just as much about profit as it is about principle,” Mr. Turpin said.United has defended its actions in the past by pointing to the role many of these doctors’ groups, financed by private equity, played in creating surprise medical bills that overwhelmed and burdened Americans around the country. Because the groups’ doctors specialize in areas like emergency care or anesthesia, patients are often shocked to find out that they are not in network even if the hospital where they received care is.Some of the doctors’ groups, like Envision Healthcare, whose doctors provide emergency-room care, pursued a strategy of keeping their doctors out of network to make more money. Patients were caught in the middle as insurers and doctors fought over out-of-network bills, and many people ended up owing large sums not covered by their health plans.When criticism of these tactics pressured Congress to consider remedies, the private-equity firms backing groups like Envision and TeamHealth spent large sums trying to block federal legislation. Lawmakers finally took action at the end of last year to protect patients from surprise bills by requiring parties to reach a fair price.But doctors say United is increasingly unwilling to come to an agreement they can accept. Envision, which eventually agreed to lower its payments and be included in the health plan’s network, said United dropped it this year because it would not agree to “drastic cuts to clinician pay.”“United turned down multiple proposals that would reduce the total cost of care for patients,” Envision said in an emailed statement. “We are left to wonder why it appears United does not want our 25,000 clinicians in their network.”The insurer has also dropped other groups. Last year, Mednax, which employed specialists in neonatology and anesthesiology, announced it had been dropped by United in four states. The company has since sold both its radiology and anesthesiology practices.