Here’s what you need to know:Hanna Riva Goldberg, 16, received her first dose of the Pfizer vaccine in New Hyde Park, N.Y., in April.Credit…Shannon Stapleton/ReutersThe Food and Drug Administration is preparing to authorize use of the Pfizer-BioNTech Covid-19 vaccine in adolescents 12 to 15 years old by early next week, according to federal officials familiar with the agency’s plans, opening up the nation’s vaccination campaign to millions more Americans.The news is highly anticipated: Eager parents have been counting down the weeks since Pfizer announced results from its trial in adolescents, showing the vaccine is at least as effective in that age group as it is in adults. The authorization could come as early as late this week, according to the federal officials, who did not give their names because they weren’t authorized to speak publicly. If it is granted, the Centers for Disease Control and Prevention’s vaccine advisory panel will likely meet the following day to review the clinical trial data and make recommendations for the vaccine’s use in adolescents.The clearance would be a major development in the nation’s vaccination campaign and welcome news to parents anxious to protect their children during summer activities and before the start of the next school year.Pfizer reported several weeks ago that none of the adolescents in the clinical trial who received the vaccine developed symptomatic infections, a sign of significant protection. The company announced in late March that volunteers produced strong antibody responses and experienced about the same side effects seen in people ages 16 to 25 years.Stephanie Caccomo, a Food and Drug Administration spokeswoman, said she could not comment on the timing of the agency’s move. “We can assure the public that we are working to review this request as quickly and transparently as possible,” she said.Over 100 million of the nation’s adults have already been fully vaccinated. But the authorization would arrive in the middle of a delicate and complex push to reach the 44 percent of adults who have so far been hesitant to get a shot or have not had access to one.With much of the world clamoring for excess supply of vaccines made in the U.S., the Pfizer-BioNTech shot’s use in adolescents could also raise questions about whether supply should be targeted to an age group that so far appears to be mostly spared from a severe bout of Covid-19.“I do think we need to have a national and global conversation about the ethics of our vaccinating kids who are low risk for serious complications from the virus when there aren’t enough vaccines in the world to protect high risk adults from dying,” said Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Center for Health Security.President Biden has come under increasing pressure to give some of the country’s supply of vaccines away, and even within the federal government some officials have urged the administration to decide soon how much vaccine is needed, lest doses expire or be shipped to states and go unused. The federal government has bought 700 million doses of three federally-authorized vaccines to be delivered before the end of July — well beyond what would be needed to cover every American.The nation’s current vaccine supply is substantial. As of Monday, around 65 million doses had been delivered but not administered, including 31 million doses of Pfizer-BioNTech’s vaccine, nearly 25 million doses of Moderna’s, and 10 million doses of Johnson & Johnson’s, according to figures collected by the Centers for Disease Control and Prevention. Both Pfizer’s and Moderna’s vaccines require two doses.Tens of millions more Pfizer-BioNTech doses — around three weeks’ worth, according to one federal official — have been manufactured and are in various stages of readiness, waiting to undergo final tests before being shipped.Moderna expects results soon from its own clinical trial involving adolescents ages 12 to 17, followed by results for children 6 months to 12 years old in the second half of this year.

United States ›
United StatesOn May 2
14-day changeNew cases
29,536
–27%
New deaths
299
–8%
World ›
WorldOn May 2
14-day changeNew cases
670,268
+7%
New deaths
9,327
+12%

U.S. vaccinations ›

Visitors at Times Square in Manhattan on Thursday.Credit…Victor J. Blue for The New York TimesNew York and its neighbors, New Jersey and Connecticut, will welcome back crowds on May 19, state officials said Monday, a major step for a region that was once a center of the coronavirus pandemic.Restaurants, offices, retail stores, theaters, museums, barber shops, amusement parks and gyms and fitness centers will all be allowed to operate at full capacity for the first time since restrictions were adopted last year to prevent the spread of the virus. Gov. Andrew M. Cuomo of New York announced the easing of pandemic restrictions on Monday as part of broader efforts to increase economic activities, including lifting curfews for food and beverage service. New York City will also return to 24-hour subway service on May 17.“Today is a milestone for New York State and a significant moment of transition,” Mr. Cuomo, a third-term Democrat, said during a news conference in his Manhattan office.Mr. Cuomo, in announcing the sweeping changes to pandemic restrictions, seemed to be trying to accelerate New York’s recovery and once again upstage his political rival, Mayor Bill de Blasio. Last week, the mayor had set a goal of July 1 for fully reopening the city.Still, Mr. Cuomo acknowledged on Monday that immediately restarting operations might not make practical or economic sense for some businesses, such as Broadway theaters. Last week the Broadway League said theatrical performances there would likely not resume until September.Businesses in New York will still have to abide by the Centers for Disease Control and Prevention’s social distancing guidelines, which require a minimum of six feet of space between individuals. So the size of crowds will still be limited by space constraints, but businesses won’t need to abide by the six-foot rule if they require that all individuals present proof of full vaccination or a negative coronavirus test result, Mr. Cuomo said. Restaurants can also get around the six-foot rule by erecting barriers between tables.For people who have received the vaccine, Mr. Cuomo said, “life should be returning to normal. You’re vaccinated. And it’s an incentive to be vaccinated.” The governor’s announcement came less than a week after Mr. de Blasio had announced that New York City would fully reopen by July 1, a proclamation that irritated Mr. Cuomo, who has the ultimate say over capacity restrictions in the state. Mr. Cuomo’s announcement effectively fast-tracked the expected end to capacity restrictions by more than a month. “As Mayor de Blasio declared, this will be the Summer of New York City,” Bill Neidhardt, the mayor’s press secretary, said after Mr. Cuomo’s announcement. “We look forward to seeing more details and are excited to have the city fully reopened in the summer.”The Metropolitan Transportation Authority, which runs the city’s subway system, initially shut down subway service from 1 a.m. to 5 a.m. on May 6 last year as subway ridership plummeted in part as commuters avoided public transit and worked from home. M.T.A. crews were dispatched to deep clean and disinfect the subways during the closings.But as recently as February, the M.T.A shortened the overnight subway closings to 2 a.m. to 4 a.m. and signaled that they soon planned to resume 24-hour service. M.T.A. officials said Monday that they planned to continue deep cleaning and disinfecting during subway operating hours. Recently, the C.D.C. acknowledged what scientists have been saying for months: The risk of catching the coronavirus from surfaces is low.According to a New York Times database, the average number of new cases a day over the last two weeks has dropped by 40 percent or more in all three states, as of Sunday. More than a third of each state’s population has been fully vaccinated, as of Monday.But experts warn that in New York City, the slowing pace of vaccinations, the prevalence of under-vaccinated areas and the spread of worrisome variants mean that the pandemic is far from over.Travelers at Seattle-Tacoma International Airport last month. The European Union says it will be open this summer to American travelers who have been fully vaccinated against Covid-19.Credit…Ruth Fremson/The New York TimesThe European Union will recommend that its member states open borders to travelers who have been fully vaccinated, it said on Monday, clearing the way for the countries to welcome more visitors.Member states are set later this week to debate the proposal, which was issued by the European Commission, the bloc’s executive arm. Visitors who have received a vaccine approved by the European Union’s drug agency would be allowed to travel freely, and individual countries could still impose tougher requirements on visitors, the proposal said.The Commission said that if certain member states were prepared to let in visitors who had tested negative, they should do the same for vaccinated ones. Unvaccinated travelers could still be permitted, but countries could require tests or quarantines.Yet the return of tourism, which the European Commission’s president, Ursula von der Leyen, spoke about last Sunday, would be a much-needed boon for countries, particularly those in southern Europe whose economies rely heavily on tourism but have been crippled by shutdowns.The announcement comes more than a year after the first bans on nonessential travel from most countries to the bloc came into effect.A handful of countries with low virus caseloads, including Australia, New Zealand and South Korea, have been exempt from the ban. The Commission said on Monday that it would expand that list by allowing in visitors — regardless of vaccination status — from countries with virus rates higher than the current limit (though still lower than the European Union average).If member states accept the proposal, they would also be able activate an “emergency brake” mechanism to suspend all travel from outside of the bloc, the Commission said, to avoid the spread of coronavirus variants.Countries including Greece, Spain and France have already said they will open for visitors who can show proof of a vaccination or a negative test.Under the new proposal, visitors would be able to enter the European Union if they received the last recommended dose of an authorized vaccine at least 14 days before arrival.Travelers would have to prove their status under a vaccination certificate program issued by the national authorities of the country they wished to travel to, according to the Commission. But until that program was in place, governments could also accept certificates from countries outside the bloc, impose quarantines or require a proof of a negative test.Oxygen cylinders outside a shop in South Delhi. A court said it would start punishing government officials for failing to deliver oxygen.Credit…Atul Loke for The New York TimesA severe shortage of medical oxygen in India has left people gasping for their final breaths in their hospital beds, a sign of government futility in its fight against a crushing wave of coronavirus infections.The latest tragic consequence came on Sunday night, when at least 12 people hospitalized with Covid-19 died in Chamarajanagar, southwestern India, because of a lack of oxygen, according to the regional authorities. Hospital officials were left desperately dialing senior government functionaries and made calls to neighboring officials for help. Videos from the hospital showed relatives of sick patients using towels to fan their loved ones in an attempt to save them.Local officials provided different accounts of the death toll at the hospital. Some said that at least 10 died from oxygen deprivation. Others said that 14 more died after the accident but that they died of comorbidities related to Covid, not directly from the oxygen shortage.Many countries, including Mexico, Nigeria, Egypt and Jordan, have faced oxygen shortages that have led to deadly accidents and driven up virus deaths. The World Health Organization estimated earlier this year that 500,000 people were in need of oxygen supply every day, but that number is likely to be much higher with the outbreak in India.The Indian authorities have said that the country has enough liquid oxygen to meet medical needs and that it is rapidly expanding its supply. But production facilities are concentrated in eastern India, far from the worst outbreaks in New Delhi and in western areas of the country, requiring several days of travel by road.Ritu Priya, a professor at the Center of Social Medicine and Community Health at Jawaharlal Nehru University in New Delhi, called the oxygen shortage a failure of governance. “We were not able to channelize oxygen distribution over the past year when that is what we should have been doing,” Dr. Priya said.“We are living from oxygen cylinder to oxygen cylinder,” she said.On Sunday, the New Delhi High Court said that it would start punishing government officials for failing to deliver oxygen after hospitals in the capital successfully sought an injunction, The Associated Press reported.The Supreme Court also weighed in on Sunday, urging the central and state governments to consider another lockdown to gain control of the virus and to create an emergency stockpile of oxygen, according to the Indian news media.Critics have blasted Mr. Modi’s handling of the crisis. A sudden, harsh lockdown imposed early in the pandemic sent millions of laborers scrambling back to their home villages and disrupted the economy. When cases dropped, Mr. Modi’s government failed to heed warnings of a potential resurgence from scientists, and its Covid-19 task force did not meet for months. Mr. Modi declared a premature victory over Covid in late January during what proved to be a mere lull in infections.Now, cremation grounds are working day and night, burning thousands of bodies. The country is rife with the more lethal and transmissible B.1.1.7 variant of the coronavirus, first found in Britain, as well as a local variant, B.1.617. Experts are worried that the unchecked outbreak will spawn more dangerous variants of the coronavirus.On Monday, the Indian federal Health Ministry reported 368,147 new cases and 3,417 deaths from the virus, a figure that generally remains low on the first day of the week. India reported new daily cases of as much as 392,488 on Saturday, a tally that no other country has ever seen. The real toll is far higher, according to experts.Indian officials announced over the weekend that the army had opened its hospitals to civilians and that the first batch of the Russian vaccine, Sputnik V, had arrived, a boost to India’s flagging inoculation campaign.Over the weekend, aid from a half-dozen countries arrived at airports across India; it included 157 ventilators from the United Arab Emirates, 500 oxygen cylinders from Taiwan and 1,000 vials of the medicine Remdesivir from Belgium.VideoOn Sunday, the United States delivered the third of six aid shipments to New Delhi, including 1,000 oxygen cylinders. Britain donated more than 400 oxygen concentrators, and France sent eight oxygen generators, each of which can serve 250 hospitalized patients.CreditCredit…Pool photo by Prakash SinghVaccines are badly needed in India, where shortages forced several states on Saturday to delay expanding access to everyone aged 18 and over. While it is a global power in vaccine production, India didn’t purchase enough doses to protect itself: Less than 2 percent of its 940 million adults have been fully vaccinated.global roundupA hospital in El Alto, Bolivia, hosted a vaccination day for older adults last week. A second batch of vaccines arrived in Bolivia through Covax, the international vaccine-sharing initiative.Credit…Martin Alipaz/EPA, via ShutterstockThe American drugmaker Moderna announced on Monday that it would supply up to 500 million doses of its coronavirus vaccine to Covax, the international vaccine-sharing initiative that aims to distribute vaccines to poor and middle-income countries that have been unable to secure deals on their own.Under the agreement, which was negotiated by Gavi, the Vaccine Alliance, the first 34 million doses will be delivered by the end of the year, and the rest through 2022.The deal covers 92 middle- and low-income countries, Moderna said. It added that the doses would be offered at the company’s “lowest-tiered price” but did not say what that was.The deal comes as countries in Europe have pledged donations to Covax to address urgent supply shortages, in particular with AstraZeneca vaccines manufactured in India, which has curtailed exports as it faces an unprecedented surge of infections.Tedros Adhanom Ghebreyesus, the director of the World Health Organization, which backs Covax, said on Monday that the initiative urgently needed 20 million doses for the second quarter of 2021.“Covax has now shipped almost 50 million doses of vaccine to 121 countries and economies, but we continue to face serious supply constraints,” Dr. Tedros said at a W.H.O. news conference. “Solving this dilemma demands courageous leadership from the world’s largest economies.”Sweden announced that it would donate a million AstraZeneca doses to Covax to address shortages, and France made an initial pledge of 500,000 last month.Although Covax was created to resolve the inequities created by a free market where the richest can buy the most, it has delivered only 49 million doses to dozens of countries, according to Gavi’s website. Health advocates have questioned its transparency and accountability, and developed countries have been accused of cutting lines and monopolizing vaccine doses.In other news from around the world:Denmark will not use the Johnson & Johnson vaccine, the Danish Health Authority announced on Monday, saying in a statement that the country could make adequate progress using other vaccines and did not need to run the risk of a rare, dangerous blood clotting condition that may be linked to the Johnson & Johnson vaccine. Dropping the vaccine from its plans will set back the country’s timetable for vaccinating adults under 40 by about a month, Danish officials said.Public fury over Nepal’s growing virus wave has been rising in the country, with many people blaming travelers from India and several other virus-stricken countries as well as government ineptitude in handling the pandemic and large political rallies. In response, Nepal halted all domestic flights on Sunday and announced that it would suspend international flights starting Wednesday. To prevent a new wave of infections in Australia, about 8,000 Australia citizens and residents are banned from returning home from India as of Monday.In Britain, a group of cross-party lawmakers urged the government on Monday to discourage all leisure travel abroad to prevent the importation of new variants into Britain and to reduce the risk of a new wave of infections. The warning comes as Prime Minister Boris Johnson plans to reopen international travel this month, with many in Britain hoping that they can travel across Europe and beyond for summer vacation.In the Philippines, President Rodrigo Duterte appeared to receive his first dose of the Sinopharm coronavirus vaccine on Monday, according to a livestream shared on Facebook by a Filipino lawmaker and Filipino news outlets. “I feel good,” Mr. Duterte said in the video, adding that he had been expecting to receive the China-backed vaccine for a long time. The vaccine has not been approved by the World Health Organization for emergency use yet, and Sinopharm has not applied for approval by the Philippine drug regulator. But Mr. Duterte received it under a permit that granted access to 10,000 doses for his security group, according to Rappler, a Manila-based news website.In Greece, outdoor restaurant service resumed on Monday after a six-month hiatus, a much-anticipated reopening after people began filling city squares and beaches as temperatures rose. Greece has gradually lifted restrictions in recent weeks, including ending quarantine requirements for visitors from dozens of countries. The authorities plan to reopen the tourism sector on May 15, when domestic travel restrictions are also set to lift.France began easing lockdown restrictions on Monday, reopening middle and high schools and lifting a ban on domestic travel. Outdoor dining at cafes and restaurants is scheduled to reopen later this month, and a 7 p.m. nightly curfew is expected to be pushed back to 9 p.m.The European Union’s drug regulator announced that it had begun evaluating clinical-trial data to extend the authorization of the Pfizer-BioNTech coronavirus vaccine to children ages 12 to 15, the first vaccine to be assessed for pediatric use in the bloc. The European Medicines Agency said the review would be accelerated, and it expects a decision in June.In Germany, the Munich Oktoberfest will be canceled for a second year in a row, the authorities in the Bavaria region said on Monday. The lawmakers cited difficulties in enforcing mask or distance rules. The last time the event ran, in September and October 2019, it attracted 6.3 million people.In a bid to improve their customer service at vaccination centers, officials in Mexico City have cued up entertainment performances — including large, bare-chested Lucha Libre wrestlers doing the limbo and men performing tricks with a surprising number of soccer balls — for those waiting for their shots.President Iván Duque of Colombia said he would withdraw a plan to overhaul the tax system to plug a fiscal shortfall caused by the pandemic after at least 17 people were killed and hundreds injured in protests against his plan. The finance minister said he would resign on Monday.Lining up for Covid-19 vaccines in Toronto in April.Credit…Chris Helgren/ReutersNaomi Harris plans to drive to Buffalo next week from her home in Toronto to get the second dose of the Pfizer coronavirus vaccine. At home, her second appointment was set for July 1, but she thought that as a caregiver for someone with cancer, that was too long to wait.Canada’s slow vaccine rollout has left some people waiting four months between doses. While at least 33 percent of Canadians have received one shot, just three percent are fully vaccinated.New daily cases reached a seven-day average over 8,700 in mid-April, according to a New York Times database, levels not seen since a winter surge. Ontario has been among the hardest hit, reporting 3,700 new cases on Sunday.Ms. Harris, 47, said she had to be “very pushy” for her mother to get vaccinated in a shorter time than expected. After her mother received a first dose in early March, her second dose was scheduled for June 30, according to Ms. Harris, “which was insane because my mom has cancer and is over 80,” she said.Eventually, their province of Ontario changed the rules for people with certain types of cancer and Ms. Harris’s mother received her second dose in early April. Ms. Harris is eligible for her shot in Buffalo as a dual Canadian and American citizen who is enrolled in a graduate program in Buffalo remotely. “I can’t take the risk of getting my mom sick,” Ms. Harris said. As supply increases, officials have said, the wait between two inoculations is expected to shorten, and some initiatives are trying to shrink the gap. Zain Manji, who runs the company Lazer from Toronto, created a text system with a friend that allows people to find vaccination sites near them. Since its start on April 30, at least 50,000 people have used it.“I think there’s been a lot of confusion around who is eligible, which locations are vaccinating people, what vaccines that they’re offering,” Mr. Manji said. “People are eager to get it and want to get it as fast as they can,” he added about the vaccine.The vaccines are coming at a crucial time: Amid a third wave, the worst-affected provinces are reporting case numbers per capita that rival those of India — although figures in India are likely to be underestimated.In Quebec, a curfew, limits on gatherings, and takeout-only dining have helped to quell cases. Jean-Sébastien Guay, 27, of Montreal had his first shot on Sunday. “It hasn’t been perfect,” he said, but officials communicated consistently. “They all work pretty hard to make it work.”Peter Hotez, a vaccine expert at Baylor College of Medicine, has been pushing for the Biden administration to offer help to Canada. “This is not a time to hold back,” Dr. Hotez said in a telephone interview. After writing on Twitter that the government should ship more Pfizer doses to Canada, he was met with emotional stories from Canadians.Adding insult to injury for some Canadians is the possibility of their country opening travel to vaccinated American tourists. “It’s frustrating for me to sit here and watch my friends in the United States going to restaurants, carrying on as if life is normal,” said Ms. Harris, who said she had been in a quasi-lockdown since November.“In the rest of the world, life is not normal.”A vaccination center in Bangkok. The world’s richest nations are vaccinating their populations at a much faster pace as the world’s poorest struggle to make a dent.Credit…Adam Dean for The New York TimesMore than 600 million people worldwide have been at least partly vaccinated against Covid-19 — meaning that more than seven billion have not. It is a striking achievement in the shadow of a staggering challenge.Half of all the doses have gone into the arms of people in countries with one-seventh of the world’s people, primarily the United States and European nations. Dozens of countries, particularly in Africa, have barely started their inoculation campaigns.As wealthy countries envision the pandemic retreating within months — while poorer ones face the prospect of years of suffering — frustration has people around the world asking why more vaccine isn’t available.Nationalism and government actions do much to help explain the stark inequity between the world’s haves and have-nots. So, for that matter, does government inaction. And the power of the pharmaceutical companies, which at times seem to hold all the cards, cannot be ignored.But much of it comes down to sheer logistics.Immunizing most of humanity in short order is a monumental task, one never attempted before, and one that experts say the world wasn’t ready to confront. They note that things have already moved with unprecedented speed: A year and a half ago, Covid-19 was unknown, and the first vaccine authorizations came less than six months ago.But there is a long way to go. Here is a look at the reasons for the vaccine shortfall.A health worker administers a Covid-19 test in Gauhati, India, on Saturday.Credit…Anupam Nath/Associated PressThe coronavirus surge that is lashing India, where countless funeral pyres cloud the night skies, is more than just a humanitarian disaster: Experts say uncontrolled outbreaks like India’s also threaten to prolong the pandemic by allowing more dangerous virus variants to mutate, spread and possibly evade vaccines.The United States will begin restricting travel from India later this week, but similar limitations on air travel from China that President Trump imposed in the early days of the pandemic proved to be ineffectual. “We can ban all the flights we want but there is literally zero way we can keep these highly contagious variants out of our country,” said Dr. Ashish Jha, the dean of the Brown University School of Public Health.What are variants, and why should we care?As the coronavirus spreads among human hosts, it invariably mutates, creating opportunities for new variants that can be more transmissible or even more deadly. One highly contagious variant, known as B.1.1.7, crushed Britain earlier this year and is already well entrenched in the United States and Europe. Recent estimates suggest that B.1.1.7 is about 60 percent more contagious and 67 percent more deadly than the original form of the virus. Another worrisome variant, P.1, is wreaking havoc across South America.On Friday, India recorded 401,993 new cases in a single day, a world record, though experts say its true numbers are far higher than what’s being reported. Peru, Brazil and other countries across South America are also experiencing devastating waves.Virologists are unsure what is driving India’s second wave. Some have pointed to a homegrown variant called B.1.617, but researchers outside of India say the limited data suggests that B.1.1.7 may be to blame.I’m already vaccinated. Should I be worried?With 44 percent of adults having received at least one dose, the United States has made great strides vaccinating its citizens, though experts say the country is far from reaching so-called herd immunity, when the virus can’t spread easily because it can’t find enough hosts. Vaccine hesitancy remains a formidable threat to reaching that threshold.In much of the world, however, vaccines are still hard to come by, especially in poorer countries. In India, less than 2 percent of the population has been fully vaccinated. “If we want to put this pandemic behind us, we can’t let the virus run wild in other parts of the world,” Dr. Jha said.Preliminary evidence suggests that the vaccines are effective against the variants, although slightly less so against some. “For now, the vaccines remain effective, but there is a trend toward less effectiveness,” said Dr. Céline Gounder, an infectious disease physician and epidemiologist at Bellevue Hospital in New York.Vaccine makers say they are poised to develop booster shots that would tackle especially troublesome variants, but such a fix would be of little help to poorer nations already struggling to obtain the existing vaccines. Experts say the best way to head off the emergence of dangerous variants is to tamp down new infections and immunize most of humanity as quickly as possible.Dr. Michael Diamond, a viral immunologist at Washington University in St. Louis, said that the longer the coronavirus circulates, the more time it has to mutate, which could eventually threaten vaccinated people; the only way to break the cycle is to ensure countries like India get enough vaccines. “In order to stop this pandemic, we have to vaccinate the whole world,” Dr. Diamond said. “There will be new waves of infection over and over again unless we vaccinate at a global scale.”A Covid-19 patient received oxygen from a gurdwara, or Sikh house of worship, last month.Credit…Atul Loke for The New York TimesWith India’s health care system overwhelmed by the country’s unprecedented Covid-19 surge, desperate relatives and friends of the infected have resorted to sending S.O.S. messages on social media. Many of those calls are being answered.More than 400,000 new coronavirus cases and thousands of deaths are being reported each day. Some people need medical oxygen, which is nearly impossible to find in Delhi, the capital. Others are hunting for medicine that is expensive on the black market, or for rare ventilators.The pleas are reaching tech-savvy engineers, lawyers, employees of nongovernmental organizations, politicians, doctors and even tuk-tuk drivers, who have mobilized online to help the sick, some of them hundreds of miles away. They have formed grass-roots networks that are stepping in where state and national governments have failed.India’s loose online aid networks rely on tools and techniques commonly used in marketing and other forms of messaging on social media. Families tag people with large followings or specialized skills who might be able to amplify their messages, while volunteer organizers use keywords to filter the flood of requests.Over a thousand people gathered to watch the Stockyards Championship Rodeo in Fort Worth, Tex., last month.Credit…Shelby Tauber for The New York TimesEarly in the pandemic, when vaccines were still just a glimmer on the horizon, the term “herd immunity” came to signify the endgame: the point when enough Americans would be protected from the virus that we could be rid of it.Now, more than half of adults in the United States have been vaccinated with at least one dose. But rates are slipping, and there is widespread consensus among public health experts that herd immunity is not attainable — not in the foreseeable future, perhaps not ever.Instead, they are coming to the conclusion that the virus will most likely become a manageable threat that will continue to circulate in the United States for years, still causing hospitalizations and deaths but in much smaller numbers.How much smaller depends in part on how much of the nation, and the world, becomes vaccinated and how the coronavirus evolves.