Early in the pandemic, there was hope that the world would one day achieve herd immunity, the point when the coronavirus lacks enough hosts to spread easily. But over a year later, the virus is crushing India with a fearsome second wave and surging in countries from Asia to Latin America.
Experts now say it is changing too quickly, new more contagious variants are spreading too easily and vaccinations are happening too slowly for herd immunity to be within reach anytime soon.
That means if the virus continues to run rampant through much of the world, it is well on its way to becoming endemic, an ever-present threat.
Virus variants are tearing through places where people gather in large numbers with few or no pandemic protocols, like wearing masks and distancing, according to Dr. David Heymann, a professor of infectious disease epidemiology at the London School of Hygiene and Tropical Medicine.
While the outbreak in India is capturing the most attention, Dr. Heymann said the pervasive reach of the virus means that the likelihood is growing that it will persist in most parts of the world.
As more people contract the virus, developing some level of immunity, and the pace of vaccinations accelerates, future outbreaks won’t be on the scale of those devastating India and Brazil, Dr. Heymann said. Smaller outbreaks that are less deadly but a constant threat should be expected, Dr. Heymann said.
“This is the natural progression of many infections we have in humans, whether it is tuberculosis or H.I.V.,” said Dr. Heymann, a former member of the Epidemiology Intelligence Service at the Centers for Disease Control and Prevention and a former senior official at the World Health Organization. “They have become endemic and we have learned to live with them and we learn how to do risk assessments and how to protect those we want to protect.”
Vaccines that are highly effective against Covid were developed rapidly, but global distribution has been plodding and unequal. As rich countries hoard vaccine doses, poorer countries face big logistical challenges to distributing the doses they manage to get and vaccine hesitancy is an issue everywhere. And experts warn the world is getting vaccinated too slowly for there to be much hope of ever eliminating the virus.
Only two countries have fully vaccinated more than half of their populations, according to the Our World in Data project at the University of Oxford. They are Israel and the East African nation of the Seychelles, an archipelago with a population of fewer than 100,000. And just a handful of other countries have at least partially vaccinated nearly 50 percent or more, including Britain, tiny Bhutan, and the United States.
Less than 10 percent of India’s vast population is at least partly vaccinated, offering little check to its onslaught of infections.
In Africa, the figure is slightly more than 1 percent.
Still, public health experts say a relatively small number of countries, mostly island nations, have largely kept the virus under control and could continue keeping it at bay after vaccinating enough people.
New Zealand, through stringent lockdowns and border closures, has all but eliminated the virus. Dr. Michael Baker, an epidemiologist at the University of Otago who helped devise the country’s coronavirus response, said New Zealand would likely achieve herd immunity by immunizing its population, but it has a long way to go with only about 4.4 percent of New Zealanders at least partially vaccinated.
“All of the surveys show there is a degree of vaccine hesitancy in New Zealand, but also a lot of people are very enthusiastic,” Dr. Baker said. “So I think we will probably get there in the end.”
While new daily cases have remained at near-world record levels, the number of deaths has dropped from a peak in February, going against the normal pattern of high cases followed eventually by high deaths. If that trendline continues, it could offer a glimmer of hope for a future scenario that scientists are rooting for: Even as the virus spreads and seems to be hurtling toward becoming endemic, it could become a less lethal threat that can be managed with vaccines that are updated periodically to protect against variants.
“It may be endemic, but not in a life-threatening way,” Dr. Michael Merson, a professor of global health at Duke University and New York University, and a former director of the World Health Organization’s Global Program on AIDS, said. “It may be more like what we see with young kids, a common cold like disease.”
Madeleine Ngo contributed reporting.
Dr. Anthony S. Fauci said on Sunday that he was open to relaxing indoor masking rules as more Americans are vaccinated against the virus, just two days after the Centers for Disease Control and Prevention belatedly emphasized the danger of airborne transmission.
Dr. Fauci, President Biden’s chief medical adviser for the pandemic, said that as vaccinations climb, “we do need to start being more liberal” in terms of rules for wearing masks indoors, though he noted that the nation was still averaging about 43,000 cases of the virus daily. “We’ve got to get it much, much lower than that,” he said.
On Friday, the C.D.C. updated its guidance about how the coronavirus spreads, stating explicitly that people could inhale airborne virus even when they were more than six feet away from an infected individual. Previously, the agency had said that most infections were acquired through “close contact, not airborne transmission.”
The update brought the agency in line with evidence of the danger from airborne droplets that epidemiologists had noted as the pandemic unfolded last year. According to some experts, it also underscored the urgency for the federal Occupational Safety and Health Administration to issue standards for employers to address potential airborne hazards in the workplace.
Dr. Fauci’s comments on Sunday came in response to a question about comments that Dr. Scott Gottlieb, the former head of the Food and Drug Administration, made last week on CNBC. Dr. Gottlieb said that relaxing indoor mask mandates now — “especially if you’re in environments where you know you have a high level of vaccination” — would give public health officials “the credibility to implement them” again in the fall or winter if cases surge.
Dr. Fauci, asked by George Stephanopoulos on ABC’s Sunday program “This Week” whether he agreed, said: “I think so, and I think you’re going to probably be seeing that as we go along, and as more people get vaccinated.”
“The C.D.C. will be, almost in real time, George, updating their recommendations and their guidelines,” Dr. Fauci continued. “But yes, we do need to start being more liberal as we get more people vaccinated.”
Over a third of the U.S. population — more than 112 million people — is fully vaccinated and another 40 million people have received the first dose of a two-dose protocol.
The C.D.C., which issues national guidance on masking, says that even vaccinated people should continue to wear masks in indoor public spaces, including restaurants when they are not actively eating and drinking. In many places across the country, it is clear that the guidance is not being followed.
In a separate interview on Sunday, on CNN’s “State of the Union,” Jeffrey Zients, Mr. Biden’s Covid response coordinator, was somewhat more circumspect than Dr. Fauci when asked about Dr. Gottlieb’s comments.
“I think everyone is tired, and wearing a mask is — it can be a pain,” Mr. Zients said. “But we’re getting there. And the light at the end of the tunnel is brighter and brighter. Let’s keep up our guard. Let’s follow the C.D.C. guidance. And the C.D.C. guidance across time will allow vaccinated people more and more privileges to take off that mask.”
Mr. Zients also suggested that instead of reaching herd immunity — the point when enough people are immune to the virus that it can no longer spread through the population — the goal should be to achieve some sense of normalcy by getting 70 percent of Americans immunized. President Biden has called for 70 percent to have at least one dose by July 4.
Reaching 70 percent will create “a pattern of decreasing cases, hospitalizations and deaths and take us down to a sustainable low level,” Mr. Zients said, pointing to Israel, a world leader in vaccinations, as a model.
In that country, vaccinations have reached almost 60 percent of the population since they began on Dec. 19 last year, and the seven-day average of new cases has dropped from a high of more than 8,600 on Jan. 17 to fewer than 60 as of Saturday.
Vaccinations are picking up pace in the European Union, a stunning turnaround after the bloc’s immunization drive stalled for months.
On average over the last week, nearly three million doses of the Covid-19 vaccine were being administered each day in the European Union, a group of 27 nations, according to Our World in Data, a University of Oxford database. Adjusted for population, the rate is roughly equivalent to the number of shots given each day in the United States, where demand has been falling.
The E.U. vaccination campaign, marred by disruptions in supplies of the AstraZeneca and Johnson & Johnson Covid-19 vaccines, pivoted last month to rely heavily on the Pfizer-BioNTech vaccine.
Last month, Ursula von der Leyen, the European Commission president, said that Pfizer had agreed to an early shipment of doses that she said should likely allow the bloc to reach its goal of inoculating 70 percent of adults by the end of the summer. The European Union announced a deal over the weekend with Pfizer and its German partner BioNTech for 2022 and 2023 that locks in 1.8 billion doses for boosters, variants and children’s vaccines.
The United States moved aggressively under the Trump administration’s Operation Warp Speed to procure millions of doses by funding and prodding vaccine production. But the European Union, rather than partnering with drugmakers as the United States did, acted more like a customer than an investor.
“I think it is overdue that the E.U. has stepped up their vaccination campaign,” said Beate Kampmann, director of the Vaccine Center at the London School of Hygiene and Tropical Medicine.
“I think in the context of the rate of deaths we’ve seen and new cases we’ve seen in the E.U., it is absolutely vital that we get the vaccine to people there very, very quickly,” she added.
The E.U.’s increase underscores the global disparities in vaccination efforts.
About 83 percent of Covid shots have been given in high- and upper-middle-income countries, while only 0.3 percent of doses have been given in low-income countries. In North America, more than 30 percent of people have received at least one dose, according to Our World in Data. In Europe, the figure is nearly 24 percent. In Africa, it’s slightly more than 1 percent.
Experts warn that if the virus can run rampant in much of the world, untamed by vaccines, dangerous variants will continue to evolve and spread, threatening all countries.
Last week, the Biden administration said it supported waiving intellectual property protections for Covid vaccines, which would need approval from the World Trade Organization. And even then, experts warn that pharmaceutical companies around the world would need technological help to make the vaccines and time to ramp up production.
European leaders like Ms. von der Leyen and President Emmanuel Macron have made it clear they think President Biden should take a different approach, and instead lift export restrictions on vaccines, which the United States has employed to keep most doses for use domestically. “We call upon all vaccine-producing countries to allow export and to avoid measures that disrupt the supply chains,” Ms. von der Leyen said in a speech last week.
But the matter is not so absolute, said Dr. Thomas Tsai, a professor who researches health policy at Harvard University. “What’s really needed is an all-of-the-above approach,” he said. Waiving patents is a big long-term step, he said, but lifting export bans would provide help sooner.
“There is a need to move toward a more comprehensive strategy” in vaccinating the world, Dr. Tsai said. “We need that same sort of Warp Speed type of commitment. It’s an investment.”
Dr. Anthony S. Fauci, the Biden administration’s top adviser on Covid-19, said on Sunday that the United States and other countries, as well as vaccine manufacturers, particularly need to help address the crisis right now in India, where less than 10 percent of the vast population is at least partly vaccinated as the country battles a devastating virus wave.
“Other countries need to chip in to be able to get either supplies to the Indians to make their own vaccines or to get vaccines donated,” Dr. Fauci said on ABC’s “This Week.” “One of the ways to do that is to have the big companies that have the capability to make vaccines to really scale up in a great way, to get literally hundreds of millions of doses to be able to get to them.”
ISTANBUL — Turkey’s health ministry on Saturday reported fewer than 20,000 new coronavirus cases in the previous 24 hours, a first since mid-March and 10 days into a lockdown.
The health ministry data shows 18,052 new cases and 281 new Covid deaths. The country’s seven-day average of new cases has been falling since April 20, when it hit a peak of more than 60,260 from fewer than 10,000 on March 3, according to data from the Our World in Data project at the University of Oxford. The plunge in new cases has been equally sharp, dropping to fewer than 24,000 as of Saturday.
Deaths, which lag infections by weeks, have only just begun to fall. The seven-day average peaked on May 2 at more than 355 and has now dropped to just over 320.
In what President Recep Tayyip Erdogan billed as a full lockdown, the government ordered nonessential workers to stay home, except to go to the nearest grocery store, starting on April 29, to last for almost three weeks. Day-care centers and kindergartens are open only for the children of workers exempt from the curfew.
However, a confederation of labor unions, known as DISK, estimated that 61 percent of the country’s workers are employed in exempted sectors, including manufacturing, construction, agriculture and transportation. In major cities like Istanbul, public transportation has been crowded, and there are traffic jams.
Turkey so far has fully vaccinated 10.3 million people, or about 12 percent of its population of 83 million; roughly three million people more have received their first dose, according to Our World in Data. The country mainly uses CoronaVac, developed in China, and has also distributed a small number of doses of the Pfizer-BioNtech vaccine.
Facing difficulties in securing enough vaccine, Turkey has resorted to postponing second doses. On April 12, the health minister, Fahrettin Koca, said 30 million more doses of the Pfizer-BioNtech would arrive in June. On April 28, he announced a deal to import 50 million doses of the Sputnik V vaccine from Russia within six months.
NEW DELHI — Doctors in India are concerned about an increasing number of potentially fatal fungal infections affecting either people who have Covid-19 or those who have recently recovered from the disease.
The condition, known as mucormycosis, has a high mortality rate and was present in India before the pandemic. It is caused by a mold that thrives in wet environments and can attack through the respiratory tract, potentially eroding facial structures and harming the brain.
The condition is relatively rare, but doctors and medical experts say it seems to be infecting some Covid patients whose weakened immune systems and underlying conditions, particularly diabetes, leave them vulnerable.
Some experts attribute the fungal infections to an increased use of steroids to treat hospitalized patients. Another factor could be that, with hospitals overwhelmed in this second wave of the pandemic, many families are self-medicating and applying oxygen therapy at home without the proper hygiene, experts say.
In the western state of Maharashtra, which includes the commercial hub of Mumbai and has been badly devastated by the pandemic, local news media reported that around 200 patients who had recovered from Covid were being treated for mucormycosis and that eight had died.
In Gujarat, a western state north of Maharashtra, the state government ordered the allocation of separate wards in hospitals for the treatment of the infection, and said it had put purchase orders for 5,000 doses of amphotericin B, a medicine used to treat it. Infections have also been reported in hospitals in the country’s capital, New Delhi.
Health experts are keeping close tabs on the situation. “We have heard that in some areas, people who are Covid-infected or recovered suffer from mucormycosis, but there is not a big outbreak of it,” Dr. V.K. Paul, who heads India’s Covid task force, said last week. “We are watching and monitoring.”
“It is a fungus that has a strong relation to diabetes,” he added. “If the person is not diabetic, it is very uncommon that the person would have mucormycosis.”
Many less-populous countries have higher percentages of diabetes, but only one — China, with a population even larger than India’s 1.38 billion — has a higher raw number of diabetics. In India, more than 10 percent of the adult population has the condition, or 77 million people. China has more than 116 million adult diabetics, or 9 percent, according to the 2019 International Diabetes Foundation Atlas.
Dr. K. Srinath Reddy, who leads the Public Health Foundation of India, said a large number of the recent reported mucormycosis cases were of hospitalized coronavirus patients who had been discharged after their recovery.
“You are using steroids to reduce the hyperimmune response, which is there in Covid,” Dr. Reddy said. “But you are reducing the resistance to other infections.”
Street parties broke out in Madrid and many other Spanish cities late Saturday to celebrate the end of a nationwide state of emergency and the lifting of curfews in most regions of the country.
The partying, however, immediately raised concerns over whether such behavior could trigger another uptick in coronavirus cases. It also intensified the political blame game over who should be held responsible if Spain’s Covid-19 situation worsens.
Thousands of people, mostly young, took over Puerta del Sol and the other main squares of Madrid. Wild celebrations also occurred in Barcelona and Seville.
In the spring of 2020, Spain was among the worst-hit countries in Europe, even though residents were under strict lockdown from mid-March to June. In October, to curtail a second wave of Covid-19, the central government declared a second state of emergency, which lasted until Sunday.
José Luis Martínez Almeida, the mayor of Madrid, on Sunday described as “lamentable” some of the scenes witnessed overnight, particularly those showing unmasked people drinking together on the streets.
He insisted that such behavior did not correspond to the “freedom” slogan that was used by Madrid’s regional leader, Isabel Díaz Ayuso, to win a landslide re-election victory last Tuesday. Voters rewarded her for defending small businesses and keeping bars and shops in Madrid open, in defiance of the central government.
“Freedom means that we live in society,” the mayor said, adding: “Freedom does not mean that you can infringe norms, freedom does not consist in getting together to drink outdoors.”
Several states are turning away Covid vaccine doses from their federal government allocations, as the daily average of coronavirus vaccine doses administered across the United States has fallen below two million for the first time since early March. Experts say the states’ smaller requests reflect a steep drop in vaccine demand in the United States.
Wisconsin officials have asked for just 8 percent of the 162,680 doses the federal government had set aside for the state next week, according to The Associated Press. In Iowa, officials asked for just 29 percent of the state’s allocated doses. And in Illinois, the state is planning to request just 9 percent of its allotted doses for everywhere, except for Chicago, for next week, The A.P. reported.
North Carolina, South Carolina, Washington State and Connecticut are also scaling back on their vaccine requests.
As demand falls and the spread of the virus slows in the United States, the Biden administration is under increasing pressure to share vaccine doses with countries like India, which has been ravaged by a catastrophic surge. About 83 percent of shots have been administered in high- and upper-middle-income countries, while only 0.3 percent of doses have been given in low-income countries.
Dr. Amesh A. Adalja, an infectious disease physician at the Johns Hopkins Center for Health Security, said that a shift in U.S. demand was expected. After people who were most eager to be vaccinated had shots, he said, the rollout of vaccines “was going to be a much more challenging prospect.”
There remain people who are hesitant to take the vaccine or may have other reasons for not doing so, and that has led to a drop in demand, Dr. Adalja said. Nationwide, since a mid-April peak of some 3.38 million doses administered each day, daily average doses have fallen by about 41 percent. In turn, that has left states ordering fewer doses than they had at first.
But some places, like New York City, Maryland and Colorado, are still asking for the full amount, The A.P. found.
To increase demand once more, officials need to make it as convenient as possible, Dr. Adalja said, including expanding the availability of walk-in clinics and even door-to-door vaccinations.
The Johnson & Johnson vaccine is notably convenient, since it’s only one dose, and can be stored at normal refrigeration temperatures for at least three months, making its distribution considerably easier. But allocations of that have remained low nationally after a pause over extremely rare cases of blood clots was lifted last month, and that has contributed to the drop in vaccinations being given more broadly.
“Once you paused the vaccine, it was going to be very hard to unpause it,” Dr. Adalja said.
President Biden, confronting lagging vaccinations, has shifted the administration’s strategy to battle the pandemic. Changes include creating a federal stockpile of vaccine doses to be given to states as needed, instead of strictly by population, and investing millions in community outreach to target underserved communities, younger Americans and those hesitant to get shots.
Mass vaccination sites will wind down in favor of smaller settings. Pharmacies will allow people to walk in for shots, and pop-up and mobile clinics will distribute vaccines, especially in rural areas. Federal officials also plan to enlist the help of family doctors and other emissaries who are trusted voices in their communities.
Dr. Adalja suggested that federal health guidance should take care to avoid “underselling the vaccine” as the nation tries to get more people vaccinated. Guidance on issues such as traveling and mask-wearing can be loosened “aggressively” for vaccinated people, Dr. Adalja said. “They seem to be several steps behind what infectious disease doctors like myself are telling people that are fully vaccinated what they can do.”
Experts warn that states where vaccinations are falling behind — particularly in the South — could be especially prone to outbreaks in the weeks ahead as more contagious virus variants spread. Texas and North Carolina are trailing the national average in vaccinations, with about 40 percent of people receiving at least one shot. In Alabama, Mississippi and Louisiana, about a third of residents have gotten their first shot.
When the pandemic hit New York City last March, Griselda San Martin, a documentary photographer, had a 5-month-old baby. She talked with other new mothers about how afraid and frustrated they felt. To capture their experiences, she began photographing the mothers and their babies in parks across the city, in poses that echo the iconic “Madonna and Child,” and asked the women to write letters to their children.
Even though the coronavirus seems to be in retreat in the United States as vaccinations continue, many school superintendents say fear of the virus itself is no longer the primary reason their students are opting out. Nor are many families expressing a strong preference for remote learning.
Rather, for every child and parent who has leapt at the opportunity to return to the classroom, others changed their lives over the past year in ways that make going back to school difficult. The consequences are likely to reverberate through the education system for years, especially if states and districts continue to give students the choice to attend school remotely.
Experts have coined the term “school hesitancy” to describe the remarkably durable resistance to a return to traditional learning.
Is watching a play on your laptop enough? That question will be put to the test starting May 17, when theaters in England reopen after a five-month shutdown.
Some shows in London are experimenting with filmed versions in advance of — or to run alongside — the same play in three dimensions, offering a choice to audiences.
When “A Splinter of Ice” begins a tour of British theaters on June 8, those who wish to can see it live, as long as they wear masks and maintain social distancing, for the first part of its travels at least. (Such protocol may change from June 21 onward, as Britain moves still further out of lockdown.)
For everyone else, a filmed version was shot on the stage of the Everyman Theater in Cheltenham, England. It stars the same actors, Oliver Ford Davies and Stephen Boxer, who will take the play out on the road.
None of this is new. The 2012 National Theater production of “The Curious Incident of the Dog in the Night-Time” was shown in movie theaters around the world long before it opened on Broadway.
The difference this time, of course, is that many potential audience members will be hesitant about crowded auditoriums.
And now for a new and vexing dilemma for states trying to vaccinate their residents against Covid-19: What to do when supply of the vaccine greatly outstrips demand?
Several states, long desperate for as many doses as they could get, are now awash in unused doses of Covid vaccines as demand dwindles and supply continues to ramp up. And many are having either to come up with new and creative ways to vaccinate the hard to reach and the hesitant or to start cutting back on supplies, even though 43 percent of Americans have not received any vaccinations.
About 112.6 million people, or 34 percent of the population, were fully vaccinated as of Saturday.
The slowing of demand was somewhat expected. During the initial rush of vaccine distribution over the winter and into the spring, appointments were coveted and often difficult to find. But today vaccines are more widely available, and officials have been left to target groups that may have missed out on shots because they are too poor, isolated or hard to reach, or because they’re either skeptical of the shot or convinced they don’t want it.
Of the 329 million doses shipped by the federal government to states, about 257 million have been administered, according to the Centers for Disease Control and Prevention. Several states are now sitting on surpluses, leaving officials to grapple with how best to find willing arms, and, in the meantime, telling the federal government to hold off on sending their full allotments.
While some states, including Colorado and Maryland, are still requesting their full allotments, others are cutting back on deliveries, according to The Associated Press. North Carolina reduced its deliveries by 40 percent last week. Connecticut asked for just 26 percent of its full delivery, and South Carolina requested just 21 percent.
At the end of last month, Arkansas asked to halt its shipment completely for at least one week, The Arkansas Democrat Gazette reported.
While demand for vaccines has slowed, the outlook for the pandemic in many parts of America seems bright. Hospitalizations in Michigan, which saw a drastic spike from mid-March through mid-April, have continued to fall since then. Gov. J.B. Pritzker of Illinois said last week that the state would fully reopen next month. In announcing his reopening plans, Mayor Bill de Blasio of New York said, “This is going to be the summer of New York City.”
Despite these signs of optimism, some public health officials are worried that the slowing demand for vaccines could lead to lingering problems from the coronavirus, including hospitalizations and deaths that are now preventable.
In a news conference last week, Gov. Jim Justice of West Virginia implored residents, particularly younger people, to “really step up.”
“If you can stand seeing one of your loved ones die, fine. I can’t stand that,” Mr. Justice said. “This thing’s a long way from being over.”
“I can’t stand these masks,” he added, tossing one onto his desk. “I want rid of them.”
The federal government distributes vaccines to jurisdictions based on population, but the Biden administration confirmed last week that it planned to change allotments based on how many vaccines were ordered by each jurisdiction.
In a news conference last week, Gov. Asa Hutchinson of Arkansas set a goal for vaccinating 50 percent of the state’s population over the next 90 days. If the state does not use the vaccines previously allocated to it by the federal government, he said, “those vaccines might go to Massachusetts, because there’s a higher acceptance rate there.”
This shift in vaccine allocations reflects a trend in many states: Fewer and fewer people are being inoculated as the weeks go on.
“It’s actually what we expected to happen,” said Dr. Amesh A. Adalja, an infectious disease physician at the Johns Hopkins Center for Health Security, adding that the next phase of vaccines would present “a much more challenging prospect.”
Jennifer Nuzzo, the lead epidemiologist for the Johns Hopkins Covid-19 Testing Insights Initiative, said that, in many cases, the easiest-to-reach populations had already been vaccinated.
The remainder largely breaks down into three groups: people who want the vaccine but have not been able to get it; people who are somewhat hesitant about the vaccine or are putting off getting a shot even though they could find one; and people who are opposed to being vaccinated, whether for religious or philosophical reasons, or because they trust disinformation that the vaccine is either dangerous, ineffective or part of a conspiracy.
“As much as I do think the demand is falling, I think there are still people who very much want to get it but haven’t been able to,” Dr. Nuzzo said. “I don’t think we have moved past the access issue.”
Among those populations are homebound older adults, who may not have been able to gain access to a vaccine site or who have been unable to schedule an appointment because of technology issues; and some working parents, or others who live in communities where vaccine providers are not close by, she said.
Numerous state and local governments are prioritizing access, propping up mobile clinics and eliminating appointment requirements at mass vaccination sites. The Biden administration is promoting similar policies aimed at increasing availability, including by directing pharmacies to offer walk-in appointments, and by shipping new allocations of the vaccine to rural health clinics.
Dr. Nuzzo said the effort to reach these groups might resemble a “get out the vote” campaign, where different networks, like pharmacies, primary care doctors and community organizations, reach out to people on an individual basis, either by going door-to-door or by contacting them some other way.
The second category — those who might be skeptical of the vaccine or are taking a “wait and see” approach before they get their own shot — presents other challenges. As the rate of new Covid-19 cases declines, motivations for getting the vaccine might decline as the perceived threat of getting sick diminishes.
The decline in vaccine demand has coincided with a significant decline in coronavirus cases from mid-April, from about 70,000 cases a day to 42,000 on Sunday.
Still, Dr. Nuzzo said the reasons for holding off on getting a shot, like some level of skepticism, could also reduce as time goes on. As more people get vaccinated, those who are unsure will see that serious side effects are almost nonexistent.
The third group — those who are outright opposed to the vaccine, and especially those who have become convinced by disinformation and conspiracy theories — might be less likely to be persuaded by the lack of side effects. “The spread of disinformation online, we have to address,” Dr. Nuzzo said. “Never in my career have I seen the scope as large as it is.”
Promoting the idea of freedom for vaccinated people could be one effective way to encourage more vaccinations, particularly among those who are open to persuasion and still making up their minds, officials say. As hesitant people look for side effects — and find few, if any — they will also see their vaccinated friends and family members enjoying the luxuries of a prepandemic life like going to concerts and seeing older relatives, and doing all those activities without the lingering fear of getting sick or getting someone else sick.
Dr. Adalja said that federal health guidance should take care to avoid “underselling the vaccine,” and that federal officials appeared to be “several steps behind what infectious disease doctors like myself are telling people that are fully vaccinated what they can do.”
It is still unclear how the remainder of unvaccinated Americans break down into these three categories. On average, providers are administering about 1.98 million doses a day, down from a high of 3.38 million on April 13.
While the Food and Drug Administration is set to authorize the Pfizer-BioNTech vaccine for adolescents next week, it is unclear how much demand will increase as a result. The soon-to-be approved age group, 12- to 15-year-olds, may represent fewer than 20 million people, according to data from the U.S. Census Bureau.
Dr. Nuzzo said that if vaccination rates continued to lag, local communities could see significant outbreaks. While the nation as a whole will not suffer the way it did this past winter, certain communities with lower vaccination rates may continue to see higher numbers of hospitalizations than is necessary.
“So many people have lost their lives,” she said, “and all of that can be prevented now.”