Covid-19 was “the eighth-highest killer of kids in this age group over the past year,” said a C.D.C. official in favor of broader authorization.WASHINGTON — An expert committee advising the Food and Drug Administration on Tuesday recommended that regulators authorize Pfizer-BioNTech’s coronavirus vaccine for 5- to 11-year-olds, bringing about 28 million children a major step closer to becoming eligible for shots.If the F.D.A. follows the panel’s advice in the coming days, as is expected, the Biden administration will have expanded vaccine access to all but the youngest Americans, while providing booster shots for many as well.Biden administration officials see the pediatric dose as crucial to keeping schools open and restoring a sense of normalcy to family and work life as the pandemic hurtles toward the end of its second year. The administration wants to be seen as doing everything possible to combat the virus and build upon positive trends, as the Delta variant ebbs and the daily drumbeat of infections and deaths fades.Younger children would start getting their shots at a time when coronavirus cases are dropping sharply. But public demand for a pediatric vaccine has been high, and some panel members said that even though young children are less likely to get severely ill from Covid-19, parents and doctors alike are anxious to protect them.Dr. Jay Portnoy, a medical director at Children’s Mercy Hospital in Kansas City, Mo., said he had seen critically ill children in the intensive care unit and “terrified” parents. “I’m looking forward to being able to actually do something to prevent that,” he said.The vote was 17-0 in favor, with one abstention. Federal regulators and scientists made a strong push, arguing that 8,300 children between 5 and 11 had been hospitalized with Covid-19 and nearly 100 had died over the course of the pandemic.Covid-19 is “the eighth-highest killer of kids in this age group over the past year,” said Dr. Amanda Cohn, a top C.D.C. vaccine official. “Use of this vaccine will prevent deaths, will prevent I.C.U. admissions and will prevent significant long-term adverse outcomes in children.”Data from Pfizer showed that the vaccine had a 90.7 percent efficacy rate in preventing symptomatic Covid-19 in a clinical trial of 5- to 11-year-olds. Still, many advisory committee members expressed concern about limited safety data, turning repeatedly to the risk of myocarditis, a rare condition involving inflammation of the heart muscle, in young vaccine recipients. Myocarditis and pericarditis, inflammation of the lining around the heart, have been tied to the Pfizer-BioNTech and Moderna vaccines, particularly in younger men.The Pfizer dose for younger children would be one-third of the strength given to people 12 and older, with two shots given three weeks apart. Experts have said that could diminish the risk of the heart-related side effects.If F.D.A. regulators follow the committee’s advice, as they typically do, an authorization could come within days. The Centers for Disease Control and Prevention’s own panel of outside experts is scheduled to meet Tuesday and Wednesday, and is also expected to endorse a pediatric dose. The C.D.C., which sets vaccine policy, would likely then quickly recommend the rollout of shots.During a long debate before the vote, some committee members questioned whether every child in the age group really needed the vaccine or whether it should be limited to those at high risk of severe Covid-19 — an easily identifiable group, with underlying conditions such as obesity or other risk factors.Dr. James E.K. Hildreth, the president and chief executive of Meharry Medical College, said that since many children between 5 and 11 may already have some immunity after contracting the virus, the need to vaccinate broadly in the age group might be less urgent.“It just seems to me that in some ways we’re vaccinating children to protect the adults, and it should be the other way around,” he said. “I do believe that children at highest risk do need to be vaccinated. But vaccinating all of the children to achieve that just seems a bit much for me.”Dr. Hildreth also bemoaned the fact that Pfizer’s pediatric trial included few children from minority groups, who are particularly at risk of bad outcomes from Covid-19.While some committee members said they wished to recommend the vaccine for a more narrow group of children, they were asked to decide simply whether the benefits of a pediatric shot outweigh the risks. “We decided to go for it with a lot of heavy conscience,” said Dr. Eric Rubin, an infectious diseases expert at the Harvard T.H. Chan School of Public Health.Dr. Paul Offit, a panel member who heads the Vaccine Education Center at Children’s Hospital of Philadelphia, said it was “nerve-racking” to make public health decisions affecting millions of children based on studies involving just a few thousand participants.But he said: “The question is, when do you know enough? And I think we certainly know that there are many children between 5 and 11 years of age who are susceptible to this disease who could very well be sick and or hospitalized, or die from it.”Dr. Peter Marks, who heads the agency’s division that oversees vaccine approvals, told the committee that nearly two million in that age group have been infected, and that a third of those hospitalized have needed intensive care.Committee members said they hoped a pediatric dose would not only keep elementary schoolers out of the hospital, but would reduce transmission of the virus and cases of long Covid.Dr. Fiona Havers, a viral disease specialist at the C.D.C., told the panel that more than 2,000 schools had been forced to close, affecting more than a million students, between early August and October because of outbreaks.Children have higher levels than adults of the neutralizing antibodies that are essential for preventing infection, she said, but are at least as likely as adults to be infected, she said. She said there appear to be many more cases of child infection than are publicly recorded.Covid-19 hospitalization rates in the 5 to 11 age group are three times as high for Black, Hispanic and Native American children as for white children, Dr. Havers added.The C.D.C. also presented blood test data indicating that 42 percent of young children had coronavirus antibodies, eliciting questions about whether many had been infected with no symptoms and developed natural immunity. Dr. Havers cautioned that the children tested were already under clinical care and may not represent the general population.It is unclear how many parents would quickly vaccinate their elementary schoolers if given the chance. Polling has showed that roughly a third are eager to do so right away, while a third prefer to wait. Since federal regulators cleared Pfizer shots for adolescents ages 12 to 15 in May, 46 percent have been fully vaccinated, compared with about 69 percent of adults.Many panel members said the data on safety and efficacy was compelling enough for government to offer shots and give parents a choice. .css-1kpebx{margin:0 auto;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-1kpebx{font-size:1.25rem;line-height:1.4375rem;}}.css-1gtxqqv{margin-bottom:0;}.css-k59gj9{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;width:100%;}.css-1e2usoh{font-family:inherit;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;border-top:1px solid #ccc;padding:10px 0px 10px 0px;background-color:#fff;}.css-1jz6h6z{font-family:inherit;font-weight:bold;font-size:1rem;line-height:1.5rem;text-align:left;}.css-1t412wb{box-sizing:border-box;margin:8px 15px 0px 15px;cursor:pointer;}.css-hhzar2{-webkit-transition:-webkit-transform ease 0.5s;-webkit-transition:transform ease 0.5s;transition:transform ease 0.5s;}.css-t54hv4{-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-1r2j9qz{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-e1ipqs{font-size:1rem;line-height:1.5rem;padding:0px 30px 0px 0px;}.css-e1ipqs a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;}.css-e1ipqs a:hover{-webkit-text-decoration:none;text-decoration:none;}.css-1o76pdf{visibility:show;height:100%;padding-bottom:20px;}.css-1sw9s96{visibility:hidden;height:0px;}.css-1in8jot{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;font-family:’nyt-franklin’,arial,helvetica,sans-serif;text-align:left;}@media (min-width:740px){.css-1in8jot{padding:20px;width:100%;}}.css-1in8jot:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1in8jot{border:none;padding:10px 0 0;border-top:2px solid #121212;}What to Know About Covid-19 Booster ShotsThe F.D.A. has authorized booster shots for millions of recipients of the Pfizer-BioNTech, Moderna and Johnson & Johnson vaccines. Pfizer and Moderna recipients who are eligible for a booster include people 65 and older, and younger adults at high risk of severe Covid-19 because of medical conditions or where they work. Eligible Pfizer and Moderna recipients can get a booster at least six months after their second dose. All Johnson & Johnson recipients will be eligible for a second shot at least two months after the first.Yes. The F.D.A. has updated its authorizations to allow medical providers to boost people with a different vaccine than the one they initially received, a strategy known as “mix and match.” Whether you received Moderna, Johnson & Johnson or Pfizer-BioNTech, you may receive a booster of any other vaccine. Regulators have not recommended any one vaccine over another as a booster. They have also remained silent on whether it is preferable to stick with the same vaccine when possible.The C.D.C. has said the conditions that qualify a person for a booster shot include: hypertension and heart disease; diabetes or obesity; cancer or blood disorders; weakened immune system; chronic lung, kidney or liver disease; dementia and certain disabilities. Pregnant women and current and former smokers are also eligible.The F.D.A. authorized boosters for workers whose jobs put them at high risk of exposure to potentially infectious people. The C.D.C. says that group includes: emergency medical workers; education workers; food and agriculture workers; manufacturing workers; corrections workers; U.S. Postal Service workers; public transit workers; grocery store workers.Yes. The C.D.C. says the Covid vaccine may be administered without regard to the timing of other vaccines, and many pharmacy sites are allowing people to schedule a flu shot at the same time as a booster dose.But Dr. Michael G. Kurilla, an official at the National Institutes of Health who abstained from the vote, said the government was embracing a “one-size-fits-all” approach.“I think for many children who have experienced Covid already, they’re probably more than adequately protected. One dose may be sufficient,” he said. “I think for the high-risk children, it’s very different.”The vote took place in a highly charged atmosphere. As of early Tuesday, nearly 140,000 public comments had been formally submitted to the agency on the issue. By contrast, only 66 comments were submitted before the panel recommended boosters for adult recipients of the Moderna and Johnson & Johnson vaccines.Over the weekend, panel members were deluged with messages in an organized email campaign urging them to vote against recommending authorization. The C.D.C. warned members of its own expert panel Tuesday afternoon that they might be targeted by a similar “misinformation campaign.”The agency said that “individuals posing as reporters may attempt to contact you and record conversations without your knowledge,” and described how committee members should report threats.Dr. Marks said that while the public had “strong feelings,” the committee was only being asked whether to allow shots, not whether to mandate them.But Dr. H. Cody Meissner, a panelist and chief of the pediatric infectious diseases division at Tufts Children’s Hospital, said he feared that state-level mandates would quickly follow, before sufficient safety data could be gathered.A. Oveta Fuller, an infectious disease expert at the University of Michigan, questioned how well the government tracks adverse side effects, asking: “Can we feel confident that should something come up, it will be detected?”Dr. Marks and Dr. Cohn, the C.D.C. official, both said the government’s safety monitoring systems would detect even rare side effects.Pfizer officials described safety data on about 4,500 children ages 5 to 11 divided into two cohorts of roughly equal size. The first group was followed for about two months, the second for about two and a half weeks. None of the children involved in Pfizer’s clinical trial developed myocarditis or pericarditis, but that was expected given the small size of the clinical trial and the rarity of those conditions.Federal health officials have said that cases of the heart conditions tend to be mild and resolve quickly, and that younger people can also develop myocarditis from the virus itself.Pfizer tried to reassure the panel that pharmacists and other providers would be able to handle children’s shots. Pediatric doses would be in vials with orange caps instead of purple, and the vials would come in orange-colored packages in order to reduce the risk that providers would mistakenly give young children doses meant for those 12 and older, officials said.Apoorva Mandavilli contributed reporting from New York and Carl Zimmer from New Haven, Conn.

The findings could add momentum for F.D.A. authorization of the pediatric dose, perhaps as early as next week, a long-awaited development that would affect 28 million children.WASHINGTON — Federal regulators evaluated for the first time on Friday the safety and efficacy of a coronavirus vaccine for children 5 to 11, saying that the benefits of staving off Covid-19 with the Pfizer-BioNTech vaccine generally outweighed the risks of the most worrisome possible side effects in that age group.The analysis came on the same day that the Food and Drug Administration posted data from Pfizer showing that the vaccine had a 90.7 percent efficacy rate in preventing symptomatic Covid-19 in a clinical trial of 5- to 11-year-olds.The findings could add momentum for F.D.A. authorization of the pediatric dose on an emergency basis, perhaps as early as next week, opening up a long-awaited new phase of the nation’s vaccination campaign. The agency’s independent vaccine expert committee is set to vote Tuesday on whether to recommend authorization.In a briefing document posted on the F.D.A. website, the agency said it had balanced the dangers of hospitalization, death or other serious consequences from Covid-19 against the risk of myocarditis. A rare condition involving inflammation of the heart muscle, myocarditis has been linked to the Pfizer-BioNTech and Moderna vaccines, especially among young men.“The overall analysis predicted that the numbers of clinically significant Covid-19-related outcomes prevented would clearly outweigh the numbers of vaccine-associated excess myocarditis cases,” regulators wrote.As is customary before a vote of the F.D.A.’s advisory committee, the regulators took no stance on whether the new use of a vaccine should be authorized.If the F.D.A. rules in favor of authorization and the Centers for Disease Control and Prevention and its own panel of vaccine experts agree, the 28 million children in that age group could become eligible for shots in the first week of November.“There’s a lot of data to be encouraged by,” said Dr. Kathryn M. Edwards, a professor of pediatrics in the division of infectious diseases at Vanderbilt University School of Medicine. She said the results exceeded the protection offered by the best flu vaccine and could eventually lead to the easing of restrictions intended to prevent elementary school children from contracting the virus.The Biden administration has been eagerly promoting the prospect of a pediatric shot, and many parents are anxiously awaiting the development. Covid-19 cases among those younger than 18 peaked in the first week of September, when nearly a quarter of a million cases were reported.But they have remained high, with more than 130,000 cases reported in the second week of October, the American Academy of Pediatrics said, accounting for a quarter of all cases nationwide. Fewer than two percent of those cases resulted in hospitalization, but that figure was based on data from only half the states, the organization said.Pfizer and BioNTech announced a month ago that their vaccine worked well for young children, but no comprehensive clinical data was released publicly until Friday. Children in the trial received two doses of 10 micrograms — one-third of the adult dose — three weeks apart. Researchers said that the dosage was safe, and that trial participants had seen only mild side effects.Of 2,268 children in the trial, twice as many were given the vaccine as received a placebo. Sixteen children who received the placebo got Covid-19, compared with three who received the vaccine. All of the Covid cases occurred in July or later, as the highly transmissible Delta variant was spreading in the United States and globally, according to the company. The F.D.A. said it could not determine whether the cases were caused by the Delta variant.Pfizer said it had follow-up safety data for an additional 2,250 children, but only for a median of two-and-a-half weeks after they received a second dose.There were no cases of severe Covid among trial participants, and no cases of two rare heart conditions that have been linked to the vaccine in teenagers and adults, especially young males. But the trial was likely not big enough to detect whether those particular conditions — myocarditis and pericarditis — might appear with any frequency in younger children.Minor side effects in the study group generally occurred more frequently after the second dose, the F.D.A. reported; the most common were pain at the injection site, fatigue and headache.The F.D.A. modeled different scenarios with varying levels of viral spread to determine the number of symptomatic Covid cases, including severe ones, that would be prevented by the vaccine. They balanced that against the risks from myocarditis and pericarditis cases associated with vaccination.Even given a low rate of Covid infections, they said, the benefits of vaccination could outweigh the risks because the virus could lead to more serious health consequences than any side effects.Researchers looked at immune responses, comparing them with levels in adults who had received the vaccine. Pfizer then deduced that the protection afforded by the lower dose in children could be as substantial as that afforded by the higher dose in adults. That approach is particularly important in small trials.After the second shot, the children had levels of neutralizing antibodies that were at least equal to those of 16-to-25-year-old volunteers in another Pfizer-BioNTech trial. Although antibody levels are just one measure of the immune system’s response, experts have said such a finding would indicate that one-third of an adult dose was the proper dosage for young children..css-1kpebx{margin:0 auto;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-1kpebx{font-size:1.25rem;line-height:1.4375rem;}}.css-1gtxqqv{margin-bottom:0;}.css-k59gj9{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;width:100%;}.css-1e2usoh{font-family:inherit;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;border-top:1px solid #ccc;padding:10px 0px 10px 0px;background-color:#fff;}.css-1jz6h6z{font-family:inherit;font-weight:bold;font-size:1rem;line-height:1.5rem;text-align:left;}.css-1t412wb{box-sizing:border-box;margin:8px 15px 0px 15px;cursor:pointer;}.css-hhzar2{-webkit-transition:-webkit-transform ease 0.5s;-webkit-transition:transform ease 0.5s;transition:transform ease 0.5s;}.css-t54hv4{-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-1r2j9qz{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-e1ipqs{font-size:1rem;line-height:1.5rem;padding:0px 30px 0px 0px;}.css-e1ipqs a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;}.css-e1ipqs a:hover{-webkit-text-decoration:none;text-decoration:none;}.css-1o76pdf{visibility:show;height:100%;padding-bottom:20px;}.css-1sw9s96{visibility:hidden;height:0px;}.css-1in8jot{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;font-family:’nyt-franklin’,arial,helvetica,sans-serif;text-align:left;}@media (min-width:740px){.css-1in8jot{padding:20px;width:100%;}}.css-1in8jot:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1in8jot{border:none;padding:10px 0 0;border-top:2px solid #121212;}What to Know About Covid-19 Booster ShotsThe F.D.A. has authorized booster shots for millions of recipients of the Pfizer-BioNTech, Moderna and Johnson & Johnson vaccines. Pfizer and Moderna recipients who are eligible for a booster include people 65 and older, and younger adults at high risk of severe Covid-19 because of medical conditions or where they work. Eligible Pfizer and Moderna recipients can get a booster at least six months after their second dose. All Johnson & Johnson recipients will be eligible for a second shot at least two months after the first.Yes. The F.D.A. has updated its authorizations to allow medical providers to boost people with a different vaccine than the one they initially received, a strategy known as “mix and match.” Whether you received Moderna, Johnson & Johnson or Pfizer-BioNTech, you may receive a booster of any other vaccine. Regulators have not recommended any one vaccine over another as a booster. They have also remained silent on whether it is preferable to stick with the same vaccine when possible.The C.D.C. has said the conditions that qualify a person for a booster shot include: hypertension and heart disease; diabetes or obesity; cancer or blood disorders; weakened immune system; chronic lung, kidney or liver disease; dementia and certain disabilities. Pregnant women and current and former smokers are also eligible.The F.D.A. authorized boosters for workers whose jobs put them at high risk of exposure to potentially infectious people. The C.D.C. says that group includes: emergency medical workers; education workers; food and agriculture workers; manufacturing workers; corrections workers; U.S. Postal Service workers; public transit workers; grocery store workers.Yes. The C.D.C. says the Covid vaccine may be administered without regard to the timing of other vaccines, and many pharmacy sites are allowing people to schedule a flu shot at the same time as a booster dose.Studies have shown that the risk of developing myocarditis or pericarditis from Covid-19 is higher than from vaccination. Still, some countries have recommended a single dose of the Pfizer-BioNTech vaccine for children 12 and older, offering less protection but possibly with a lower risk of side effects.Experts will almost certainly raise concerns about those side effects at the F.D.A. advisory committee meeting, according to Dr. H. Cody Meissner, a member of the panel and the chief of the Division of Pediatric Infectious Diseases at Tufts Children’s Hospital in Boston.“I certainly hope that we’re in a position to to recommend this because people are certainly waiting for it, they’re anxious to have it,” he said. “But our responsibility is to balance both risk and benefit.”Vaccine experts have said that Pfizer’s lower dosing could mitigate risks. “We always like to use the least amount of vaccine that’s needed to generate an immune response,” Dr. Edwards, the Vanderbilt expert, said, “because it’s generally associated with fewer adverse events.”Dr. Brian Feingold, an expert on heart inflammation in children at the UPMC Children’s Hospital of Pittsburgh, said that, “If you just focus on myocarditis or other potentially rare things, you’re probably still going to be left wanting more information.”But “we cannot consider a risk in isolation,” he added. “Risks from Covid need to be considered when you make a decision about whether this vaccine has greater net benefit.”Dr. Edwards said that researchers and regulators were in a quandary. “The more people that you that you enroll, the more time that it takes,” she said. “A lot of times, in order to really look at the data for very rare events, you’re not going to be able to do that in studies until the vaccine is really used more broadly.”The Centers for Disease Control and Prevention, which sets vaccine policy for the government, has scheduled a meeting of its advisory committee for Nov. 2 and 3 to consider the issue. Federal officials have said they intend to ship 15 million doses to the states immediately if regulatory and health officials authorize the move. The needles that administer the vaccine and the vials that hold it will need to be smaller for children who are still largely in elementary school.About 17 million adolescents aged 12 to 15 became eligible for the Pfizer-BioNTech vaccine in May. Vaccine manufacturers continue to study the possibility of a vaccine for those aged six months to 5 years old.Only about one in three parents of 5- to 11-year-olds planned to get their children inoculated “right away” once a vaccine is authorized, according to polling by the Kaiser Family Foundation conducted last month. Another third said they wanted to “wait and see” how the vaccine affected children.But that same polling showed that reluctance among parents of teenagers had dropped in the months since vaccines became available to that age group.Aina J. Khan

The agency may act this week, when it is expected to authorize booster shots for recipients of the Moderna and Johnson & Johnson vaccines.WASHINGTON — The Food and Drug Administration is planning to allow Americans to receive a different Covid-19 vaccine as a booster than the one they initially received, a move that could reduce the appeal of the Johnson & Johnson vaccine and provide flexibility to doctors and other vaccinators.The government would not recommend one shot over another, and it might note that using the same vaccine as a booster when possible is preferable, people familiar with the agency’s planning said. But vaccine providers could use their discretion to offer a different brand, a freedom that state health officials have been requesting for weeks.The approach was foreshadowed on Friday, when researchers presented the findings of a federally funded “mix and match” study to an expert committee that advises the Food and Drug Administration. The study found that recipients of Johnson & Johnson’s single-dose shot who received a Moderna booster saw their antibody levels rise 76-fold in 15 days, compared with only a fourfold rise after an extra dose of Johnson & Johnson.Federal regulators this week are aiming to greatly expand the number of Americans eligible for booster shots. The F.D.A. is expected to authorize boosters of the Moderna and Johnson & Johnson vaccines by Wednesday evening; it could allow the mix-and-match approach by then. The agency last month authorized booster shots of the Pfizer-BioNTech vaccine, at least six months after the second dose.An advisory committee of the Centers for Disease Control and Prevention will take up the booster issue on Thursday; the agency will then issue its own recommendations. By the end of the week, tens of millions more Americans could be eligible for extra shots.The study presented to the F.D.A.’s advisory panel last week, conducted by the National Institutes of Health, suggested that Johnson & Johnson recipients might benefit most from a booster shot of the Moderna vaccine. A shot of the Pfizer-BioNTech vaccine also raised the antibody levels of Johnson & Johnson recipients more than Johnson & Johnson did, the study found, although not as much as Moderna did.

Those eligible for the extra shot would include adults over 65 and others at high risk — the same groups now eligible for a Pfizer-BioNTech boostWASHINGTON — A panel of independent medical experts on Thursday unanimously recommended Moderna booster shots for many of those who had received the company’s coronavirus vaccine, paving the way to sharply expand the number of people eligible for an additional shot in the United States.The advisory panel to the Food and Drug Administration voted 19 to 0 in favor of emergency authorization of a half-dose booster, at least six months after the second dose. Those eligible for the extra shot would include people over 65 and other adults considered at high risk — the same groups now eligible for a Pfizer-BioNTech booster.The F.D.A. typically follows the panel’s advice, and should rule within days.The recommendations come as the nation is seeing a decline in coronavirus cases but still faces nearly 90,000 new infections and roughly 1,800 deaths per day. The Biden administration has cast booster shots as an additional tool in the battle against the pandemic, while acknowledging that controlling the disease’s spread depends upon vaccinating tens of millions of Americans for the first time.In a speech at the White House on Thursday, President Biden once again sought to rally businesses to support vaccination mandates that he said would help reduce the ranks of the unvaccinated in the United States, calling the number of people who have not gotten even a first shot “unacceptably high.” Mr. Biden encouraged Americans to seek out booster shots when they become eligible, calling them “free, available and convenient.”More than seven million people in the United States have already obtained booster doses of the Pfizer-BioNTech vaccine, and more than a million have received third doses of Moderna’s, even though only those with immune deficiencies are officially eligible.Thursday’s vote was considerably smoother than the one the panel held last month, after a chaotic and at times acrimonious debate on whether the F.D.A. should authorize booster shots for Pfizer-BioNTech recipients.On Friday, the same expert committee will meet to discuss and vote on whether the roughly 15 million people who received the single-dose Johnson & Johnson vaccine should also be eligible for booster doses. Its members are also supposed to discuss a new federal study that suggests those Americans might be better off getting a booster dose of the Moderna or Pfizer-BioNTech vaccines.If the F.D.A. quickly authorizes Moderna booster doses, and if the Centers for Disease Control and Prevention signs off after a meeting of its own committee of vaccine experts next week, people in the eligible groups could begin seeking out the shots soon after. In addition to people over 65, those groups include younger adults at high risk of severe Covid-19 or serious complications because of medical conditions or their jobs.Some committee members on Thursday decried the lack of more robust data justifying a booster. Dr. Archana Chatterjee, an infectious disease expert at Rosalind Franklin University, pointed out that cases were already declining here without widely available booster doses.Other members said that the F.D.A. had set a precedent by authorizing additional shots for many recipients of the Pfizer-BioNTech vaccine, making it hard to deny vulnerable Americans who received the Moderna vaccine a chance to receive a booster.“From a pragmatic point of view,” said Dr. Stanley Perlman of the University of Iowa, a committee member, “because we’ve already approved it for Pfizer, I don’t see how we can possibly not approve it for Moderna.”To date, more than 103 million people in the United States have been fully vaccinated with Pfizer’s product, more than 69 million with Moderna’s and about 15 million with the Johnson & Johnson shot.Dr. Patrick Moore, a panel member and virologist at the University of Pittsburgh, said he voted to recommend a Moderna booster based on a “gut feeling, rather than based on really, truly serious data.” Others questioned whether half a dose was the right amount, and whether a Moderna booster would work better if it was given at least eight months after the second shot, instead of six months.“I’m not sure we have actually identified the optimal regimen for these vaccines,” said Dr. Michael Kurilla, an infectious disease expert at the National Institutes of Health.The panel made clear it did not favor expanding eligibility for booster shots beyond the higher-risk groups that qualify for Pfizer boosters. No vote was taken on that question, but the committee expressed concern that booster eligibility decisions could become a slippery slope.Several experts said they were worried about recommending additional shots based on clinical trial results from just a few hundred participants.“I’m not sure that we want to just explore it willy-nilly by giving it to a lot of people,” said Dr. Eric Rubin, an adjunct professor of immunology and infectious diseases at the Harvard T.H. Chan School of Public Health.Dr. Peter Marks, the F.D.A.’s top vaccine regulator, said the agency’s experts would take the panel’s concerns to heart in considering whether younger adults without significant risk factors should become eligible for boosters. The agency “heard pretty loud and clearly that there was not a lot of appetite for moving down the age range very significantly, if at all,” he said.State health officials say that the staggered rollout of boosters has left some especially vulnerable people — for example, elderly residents of nursing homes who got the Moderna vaccine — in the lurch. But some panel members said on Thursday that nearly two months after the Biden administration announced its booster plan, the rationale remained vague..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-3btd0c{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:1rem;line-height:1.375rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-3btd0c{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-3btd0c strong{font-weight:600;}.css-3btd0c em{font-style:italic;}.css-1kpebx{margin:0 auto;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-1kpebx{font-size:1.25rem;line-height:1.4375rem;}}.css-1gtxqqv{margin-bottom:0;}.css-16ed7iq{width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:10px 0;background-color:white;}.css-pmm6ed{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}.css-pmm6ed > :not(:first-child){margin-left:5px;}.css-5gimkt{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.8125rem;font-weight:700;-webkit-letter-spacing:0.03em;-moz-letter-spacing:0.03em;-ms-letter-spacing:0.03em;letter-spacing:0.03em;text-transform:uppercase;color:#333;}.css-5gimkt:after{content:’Collapse’;}.css-rdoyk0{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-eb027h{max-height:5000px;-webkit-transition:max-height 0.5s ease;transition:max-height 0.5s ease;}.css-6mllg9{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;position:relative;opacity:0;}.css-6mllg9:before{content:”;background-image:linear-gradient(180deg,transparent,#ffffff);background-image:-webkit-linear-gradient(270deg,rgba(255,255,255,0),#ffffff);height:80px;width:100%;position:absolute;bottom:0px;pointer-events:none;}.css-19zsuqr{display:block;margin-bottom:0.9375rem;}.css-12vbvwq{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-12vbvwq{padding:20px;width:100%;}}.css-12vbvwq:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-12vbvwq{border:none;padding:10px 0 0;border-top:2px solid #121212;}.css-12vbvwq[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-12vbvwq[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-12vbvwq[data-truncated] .css-5gimkt:after{content:’See more’;}.css-12vbvwq[data-truncated] .css-6mllg9{opacity:1;}.css-qjk116{margin:0 auto;overflow:hidden;}.css-qjk116 strong{font-weight:700;}.css-qjk116 em{font-style:italic;}.css-qjk116 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:visited{color:#326891;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:hover{-webkit-text-decoration:none;text-decoration:none;}“I just worry that we haven’t clearly defined what the goal” is, said Dr. Paul Offit, an infectious disease expert with the Children’s Hospital of Philadelphia. Declining levels of neutralizing antibodies and eroding protection against mild or asymptomatic infection are “inevitable,” he said, adding that aiming to prevent even mild cases “is a high bar to which we hold no other vaccine.”Although the F.D.A. took no official stance on Moderna’s request for booster authorization, some agency officials made a general case for booster shots to the committee. Dr. Marks said the vaccines’ effectiveness against mild and moderate disease appears to wane over time, and that even less severe cases of Covid-19 might lead to long-lasting symptoms and other health consequences.Overall, Moderna officials did not make as strong a case for extra shots as Pfizer last month.Moderna’s potency has held up better than Pfizer’s over time. Unlike Pfizer, the company did not contend that recipients of its vaccine needed a booster to prevent severe disease or hospitalization, instead concentrating its arguments on preventing infection.Moderna met one of the F.D.A.’s criteria for a booster shot, reporting that the mean antibody level of participants in its study was 1.8 times as high after the booster than it was after the second shot. But it narrowly failed to meet another requirement. It raised neutralizing antibodies at least fourfold in 87.9 percent of people compared to after the second dose, while the agency required that level of boost for 88.4 percent of participants.Some experts questioned whether Moderna had gathered enough data on potential side effects. Regulators and scientists have been especially concerned about the risks of the heart conditions myocarditis, or inflammation of the heart muscle, and pericarditis, or inflammation of the lining around the heart.The F.D.A. in June attached warnings about those risks to the Pfizer-BioNTech and Moderna vaccines, and officials on Thursday cited an elevated risk in men between 18 and 25 who were fully vaccinated with either Moderna or Pfizer-BioNTech.A key part of Thursday’s discussion revolved around Israel’s booster campaign for the Pfizer-BioNTech vaccine. The Biden administration has been closely watching Israel’s experience, because the country has a nationalized health care system that allows it to closely track vaccine recipients.A top Israeli health official told the committee that her government’s booster campaign had changed the course of the pandemic there. She said Israel saw dramatically lower rates of both infection and severe disease among those who received a booster shot compared to those who had not. It was not clear, though, whether other factors, such as the decline of the Delta variant, also had an effect.Dr. Mark Sawyer, a professor in the School of Medicine at University of California San Diego, said even though the Moderna vaccine was different, Israel’s data was compelling.But Dr. Kurilla of the National Institutes of Health questioned whether Israel’s booster campaign deserved so much credit, noting that the nation’s latest drop in infection rates seemed to fit in with previous waves of the virus.He asked Dr. Sharon Alroy-Preis, Israel’s director of public health services, whether she believed that a third injection of Pfizer’s vaccine would extend protection for a long time, or whether “you’ll be back in another six months” for another booster.Dr. Alroy-Preis noted that some vaccines offer protection for years after a booster shot. Whether that is true of coronavirus vaccines, she said, is “the million-dollar question.”

The agency has promised to move quickly on the request and has tentatively scheduled a meeting at the end of the month to consider it.WASHINGTON — Pfizer and BioNTech said on Thursday morning that they had asked federal regulators to authorize emergency use of their coronavirus vaccine for children ages 5 to 11, a move that could help protect more than 28 million people in the United States.The companies have said they were submitting data supporting the change to the Food and Drug Administration. The agency has promised to move quickly on the request and has tentatively scheduled a meeting on Oct. 26 to consider it. A ruling is expected between Halloween and Thanksgiving.Parents across the United States are anxiously awaiting the regulators’ decision, which could affect family life and the operation of schools. Clearance depends not only on the strength of the clinical trial data, but on whether they can prove to regulators that they are able to properly manufacture a new pediatric formulation.Dr. Janet Woodcock, the acting F.D.A. commissioner, said last week that children might require “a different dosage or formulation from that used in an older pediatric population or adults.”Pfizer has proposed giving children one-third of the adult dosage. That might require adding more diluent to each injection or using a different vial or syringe. The company was expected to describe the method it intended to use in its submission to the Food and Drug Administration.Regulators will have to examine the purity and stability of mass-manufactured doses of the vaccine and determine that it matches the quality and potency of doses given to children in clinical trials. A pediatric dose will also most likely require new labeling, with special codes that would allow the Centers for Disease Control and Prevention to track specific lots in case of reports of serious side effects.Children rarely become severely ill from Covid-19, but the Delta variant drove nearly 30,000 of them to hospitals in August. According to the American Academy of Pediatrics, nearly 5.9 million Americans younger than 18 have been infected with the coronavirus. Of the roughly 500 Americans under 18 who have died, about 125 were children ages 5 to 11.“It really bothers me when people say kids don’t die of Covid,” said Dr. Grace Lee, an associate chief medical officer at Stanford Children’s Health who also leads a key advisory committee to the C.D.C. “They die of Covid. It’s heartbreaking.”About one in every six Americans infected since the beginning of the pandemic was under 18 years old. But with the surge of the Delta variant, children accounted for as many as one in four infections last month, according to the American Academy of Pediatrics. The Food and Drug Administration authorized emergency use of Pfizer’s vaccine for 12- to 15-year-olds in May.The infection rate in the United States is currently falling, prompting hope that the Delta variant is ebbing. But public health experts worry that the onset of colder weather could result in increased transmission.Although federal regulators are under enormous pressure to quickly review Pfizer’s application, they also face other pressing decisions. Next week, they might rule on whether people who received the Moderna and Johnson & Johnson coronavirus vaccines should receive booster shots, both potentially contentious decisions.Public health experts have said that the agency’s review of a Pfizer pediatric dose would be closely scrutinized. According to a recent survey conducted by the Kaiser Family Foundation, roughly a third of parents of children between ages 5 and 11 said they would wait and see before allowing their children to receive such a shot.Dr. Walt A. Orenstein, an epidemiologist at Emory University and a former director of the U.S. immunization program, said that given the competing pressures on the Food and Drug Administration to make vaccine decisions quickly but carefully, public discussion was essential.He said many parents were wavering between fear of Covid-19 and fear of side effects of a pediatric vaccine. If they were less worried about the consequences of coronavirus infection, he said, safety would be their top priority. If they were more worried, the vaccine’s effectiveness would matter more. As with other vaccines, Dr. Orenstein said, pediatricians would play a critical role in easing parental anxiety..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-3btd0c{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:1rem;line-height:1.375rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-3btd0c{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-3btd0c strong{font-weight:600;}.css-3btd0c em{font-style:italic;}.css-1kpebx{margin:0 auto;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-1kpebx{font-size:1.25rem;line-height:1.4375rem;}}.css-1gtxqqv{margin-bottom:0;}.css-16ed7iq{width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:10px 0;background-color:white;}.css-pmm6ed{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}.css-pmm6ed > :not(:first-child){margin-left:5px;}.css-5gimkt{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.8125rem;font-weight:700;-webkit-letter-spacing:0.03em;-moz-letter-spacing:0.03em;-ms-letter-spacing:0.03em;letter-spacing:0.03em;text-transform:uppercase;color:#333;}.css-5gimkt:after{content:’Collapse’;}.css-rdoyk0{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-eb027h{max-height:5000px;-webkit-transition:max-height 0.5s ease;transition:max-height 0.5s ease;}.css-6mllg9{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;position:relative;opacity:0;}.css-6mllg9:before{content:”;background-image:linear-gradient(180deg,transparent,#ffffff);background-image:-webkit-linear-gradient(270deg,rgba(255,255,255,0),#ffffff);height:80px;width:100%;position:absolute;bottom:0px;pointer-events:none;}.css-19zsuqr{display:block;margin-bottom:0.9375rem;}.css-12vbvwq{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-12vbvwq{padding:20px;width:100%;}}.css-12vbvwq:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-12vbvwq{border:none;padding:10px 0 0;border-top:2px solid #121212;}.css-12vbvwq[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-12vbvwq[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-12vbvwq[data-truncated] .css-5gimkt:after{content:’See more’;}.css-12vbvwq[data-truncated] .css-6mllg9{opacity:1;}.css-qjk116{margin:0 auto;overflow:hidden;}.css-qjk116 strong{font-weight:700;}.css-qjk116 em{font-style:italic;}.css-qjk116 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:visited{color:#326891;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:hover{-webkit-text-decoration:none;text-decoration:none;}Pfizer’s clinical trial for children was not intended to draw meaningful conclusions about the vaccine’s ability to prevent disease or hospitalizations. Instead, researchers looked at antibody levels, comparing them with levels in adults that had conferred high protection. Regulators are expected to compare those immune responses to vaccine efficacy data in the adult population.The trial included 2,268 children, two-thirds of whom had received two doses of the vaccine three weeks apart. The remaining volunteers were injected with two doses of saltwater placebo. Regulators over the summer asked for the trial size to be expanded to 3,000 children.At a virtual panel on Covid-19 last week, Norman Baylor, the former director of the Food and Drug Administration’s vaccines office, said that the number of participants in Pfizerpediatric study was noticeably small. The adult trial involved about 44,000 people.“It does beg the question of the size, given what we have for the adults: Would one expect more for the pediatric population?” he said. “They may be thinking, ‘Well, we know the vaccine is safe, because look at how many people we had in the adults.’ But as we know, things may shift in that pediatric population.”The Pfizer-BioNTech and Moderna vaccines have been tied to increased risks of myocarditis, or inflammation of the heart muscle; and pericarditis, inflammation of the lining around the heart, particularly in younger men. In August, the Food and Drug Administration published results from an analysis of Pfizer-BioNTech’s vaccine that used a U.S. health care claims database and found that the risk of the conditions in 16- and 17-year-old vaccinated boys could be as high as 1 in 5,000.The cases in the database were unconfirmed, but they were considered a reasonable estimate of possible risk, the agency wrote.A lower dose of the vaccine for children could alleviate those concerns.Officials in a number of countries have recommended a single dose of the Pfizer-BioNTech vaccine for children ages 12 and older, which would provide partial protection from the virus, but without the potential effects occasionally observed after two doses. Sweden and Denmark joined those countries, announcing on Wednesday that adolescents should get only one dose of the Moderna vaccine.Amy Schoenfeld Walker

A week before President Biden’s plan is to roll out, scientists are at odds about whether extra coronavirus shots are needed and for whom.WASHINGTON — Almost a month ago, President Biden announced a plan to make coronavirus booster shots available to most adults in the United States eight months after they received their second dose. But a week before the plan is to roll out, its contours are up in the air amid a chorus of dissent inside and outside the government.The White House has already been forced to delay offering boosters to recipients of the Moderna vaccine, and for now it is planning third shots only for those who received the Pfizer-BioNTech vaccine. Depending on what two public health agencies decide in the coming days, the administration may have to change course again, perhaps restricting extra shots to older Americans and others who are particularly vulnerable to serious illness.A series of dueling reviews this week illustrated the fierce argument among scientists about whether boosters are needed, and if so, for whom. A study released on Wednesday in The New England Journal of Medicine appears to bolster the case made by the White House and its senior health advisers, stating that those who received a third shot of the Pfizer vaccine in Israel were far less likely to develop severe Covid than those who received two injections.But a review by regulators at the Food and Drug Administration, also made public on Wednesday, looked at broader evidence on third doses of the Pfizer vaccine and raised caveats.And in The Lancet this week, an article written by two of the Food and Drug Administration’s top vaccine scientists, among others, argued that there was no credible evidence that the vaccines’ potency against severe disease declined substantially over time. The two scientists had announced that they would leave the agency this fall, but their public opposition to the administration’s plan caught the F.D.A.’s top leaders by surprise and forced the White House on the defensive.Jen Psaki, the White House press secretary, stressed on Wednesday that the administration’s most senior health officials — including Dr. Janet Woodcock, the acting commissioner of the Food and Drug Administration, and Dr. Rochelle P. Walensky, the director of the Centers for Disease Control and Prevention — had signed a statement announcing Mr. Biden’s booster plan. “Nothing has changed as it relates to the eight top doctors who put out that statement, almost a month ago,” Ms. Psaki said.What comes next partly depends on crucial meetings of expert advisory committees to both the F.D.A., which is responsible for authorizing vaccines, and the C.D.C., which typically has the final word on vaccination policies.The F.D.A. committee will meet on Friday to discuss and vote on Pfizer-BioNTech’s application to offer third shots to people 16 and older. The C.D.C. panel is expected to meet next week. Agency officials are not required to follow the recommendations of their outside expert panels, but they generally do so.Depending on the experts’ reaction to the data review that F.D.A. regulators posted on Wednesday, the agency could decide to scale back an authorization. Even if the Food and Drug Administration approves the application as it currently stands, however, the C.D.C. might recommend boosters only for those 65 and older or others who are particularly at risk, according to people familiar with the discussions.The plan to start offering extra shots next week was announced when the White House was under growing pressure to move on boosters. Because of the highly contagious Delta variant, hospitalizations and deaths were soaring, albeit largely among the unvaccinated. Breakthrough infections were becoming more common. France, Germany and Israel were moving faster than the United States to offer boosters. And several governors were publicly calling on Mr. Biden to follow suit..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-3btd0c{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:1rem;line-height:1.375rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-3btd0c{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-3btd0c strong{font-weight:600;}.css-3btd0c em{font-style:italic;}.css-1kpebx{margin:0 auto;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-1kpebx{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-1kpebx{font-size:1.25rem;line-height:1.4375rem;}}.css-1gtxqqv{margin-bottom:0;}.css-19zsuqr{display:block;margin-bottom:0.9375rem;}.css-12vbvwq{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-12vbvwq{padding:20px;width:100%;}}.css-12vbvwq:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-12vbvwq{border:none;padding:10px 0 0;border-top:2px solid #121212;}.css-12vbvwq[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-12vbvwq[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-12vbvwq[data-truncated] .css-5gimkt:after{content:’See more’;}.css-12vbvwq[data-truncated] .css-6mllg9{opacity:1;}.css-qjk116{margin:0 auto;overflow:hidden;}.css-qjk116 strong{font-weight:700;}.css-qjk116 em{font-style:italic;}.css-qjk116 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:visited{color:#326891;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:hover{-webkit-text-decoration:none;text-decoration:none;}Administration officials have started making the case that offering boosters only to older people would not be a huge change from the president’s original plan. Because older adults were vaccinated first, they make up a disproportionate number of those who were vaccinated at least eight months ago.Several officials suggested that the difference from Mr. Biden’s original announcement would be minimal as long as some people are offered boosters next week — even if it is only older people who received the Pfizer vaccine.John P. Moore, a virologist at Weill Cornell Medicine, said that the White House was under political pressure after declaring that boosters were necessary and that they would be available next week pending regulatory approval.“Weeks ago, the administration decided that the public needs cake and deserves cake, and so shall have cake,” he said. “Now, the public expects cake and would be very annoyed if its cake was taken away at this point.”Receiving a third dose of the Pfizer vaccine in Ramat Gan, Israel, last month. The Israeli government began offering booster shots in August. Oded Balilty/Associated PressThe backpedaling is a result of what some describe as a double mistake by the White House: First, officials pinpointed a specific week when additional shots would be rolled out. Second, they announced a broad plan covering the Pfizer and Moderna vaccines before regulators had time to review or even gather all the necessary data.“We just got things turned around,” said Dr. Jesse L. Goodman, a former chief scientist at the Food and Drug Administration. “The administration and the leaders of the scientific agencies who signed on got out in front of any public discussion, airing of the data or vetting of it. That put the F.D.A. and the C.D.C. and their advisory committees in a corner.”Dr. Woodcock, the acting F.D.A. commissioner, privately warned that it was risky to announce a timetable, especially for multiple vaccines, according to people familiar with the discussions. The F.D.A. and the C.D.C. meetings in the coming days and Pfizer’s application for approval of its booster dose appear to be conforming to the timetable the administration proposed in August.Like other senior health officials, Dr. Woodcock had hoped that booster shots could be offered this month not only for Pfizer and Moderna recipients, but for recipients of Johnson & Johnson’s one-dose vaccine as well, according to people familiar with the deliberations. But the administration had to limit its plan to Pfizer recipients, officials said, because neither Moderna nor Johnson & Johnson delivered the expected data in time.While Mr. Biden publicly noted that his strategy depended on regulatory action, he also made the plan sound all but definite. “It’s simple,” he said at the time. “Eight months after your second shot, get your booster shot.”In interviews, senior administration officials defended the decision to specify a date for the rollout, saying that precious time would have been lost if pharmacies, providers and state officials were not prepared.The data from Israel, which offered boosters first, was particularly concerning to U.S. health officials..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-3btd0c{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:1rem;line-height:1.375rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-3btd0c{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-3btd0c strong{font-weight:600;}.css-3btd0c em{font-style:italic;}.css-w739ur{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-w739ur{font-size:1.25rem;line-height:1.4375rem;}}.css-9s9ecg{margin-bottom:15px;}.css-16ed7iq{width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:10px 0;background-color:white;}.css-pmm6ed{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}.css-pmm6ed > :not(:first-child){margin-left:5px;}.css-5gimkt{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.8125rem;font-weight:700;-webkit-letter-spacing:0.03em;-moz-letter-spacing:0.03em;-ms-letter-spacing:0.03em;letter-spacing:0.03em;text-transform:uppercase;color:#333;}.css-5gimkt:after{content:’Collapse’;}.css-rdoyk0{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-eb027h{max-height:5000px;-webkit-transition:max-height 0.5s ease;transition:max-height 0.5s ease;}.css-6mllg9{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;position:relative;opacity:0;}.css-6mllg9:before{content:”;background-image:linear-gradient(180deg,transparent,#ffffff);background-image:-webkit-linear-gradient(270deg,rgba(255,255,255,0),#ffffff);height:80px;width:100%;position:absolute;bottom:0px;pointer-events:none;}.css-uf1ume{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;}.css-wxi1cx{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-self:flex-end;-ms-flex-item-align:end;align-self:flex-end;}.css-12vbvwq{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-12vbvwq{padding:20px;width:100%;}}.css-12vbvwq:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-12vbvwq{border:none;padding:10px 0 0;border-top:2px solid #121212;}.css-12vbvwq[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-12vbvwq[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-12vbvwq[data-truncated] .css-5gimkt:after{content:’See more’;}.css-12vbvwq[data-truncated] .css-6mllg9{opacity:1;}.css-qjk116{margin:0 auto;overflow:hidden;}.css-qjk116 strong{font-weight:700;}.css-qjk116 em{font-style:italic;}.css-qjk116 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:visited{color:#326891;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:hover{-webkit-text-decoration:none;text-decoration:none;}In the New England Journal of Medicine article on Wednesday, researchers said they analyzed health records of more than 1.1 million people in Israel who had received both doses of the Pfizer vaccine at least five months earlier. They found that the rate of severe disease among people over 60 who had received a third shot at least 12 days earlier was nearly twentyfold lower than among those who had received two injections.The Food and Drug Administration has invited Dr. Sharon Alroy-Preis, Israel’s head of public health services and a co-author of the study, to describe her country’s experience with boosters to the advisory committee on Friday. In an interview, Dr. Alroy-Preis said Israel had vaccinated more of its population faster than other countries and therefore saw the effect of waning immunity much earlier.If the United States does not start offering booster shots, she said, more fully vaccinated people will contract severe Covid-19, as they did in Israel. “I am sure of that,” she said.Before Israel’s government began offering third shots in August, Dr. Alroy-Preis said, people who were fully immunized with the Pfizer vaccine made up at least half of severely or critically ill Covid patients. The number of those patients is now less than half what officials had previously projected, she said, and the spread of the virus has slowed.“We are beginning to control the fourth wave,” Dr. Alroy-Preis said, “mainly by vaccinating people with third doses.”Yet vaccine experts said on Wednesday that what the Israeli data show — that a booster can enhance protection for a few weeks in older adults — is unsurprising and does not necessarily indicate long-term benefit. There are differences between Israel and the United States that could lead to different outcomes, scientists have warned.The Food and Drug Administration on Wednesday cautioned its advisory committee from putting too much weight on the experiences of other countries.“While observational studies can enable understanding of real-world effectiveness, there are known and unknown biases that can affect their reliability,” regulators wrote in a briefing paper. Studies conducted in the United States “may most accurately represent vaccine effectiveness in the U.S. population,” they added.The Food and Drug Administration’s analysis also noted that Pfizer had gathered data on immune responses against the Delta variant in only two dozen people. The company said in a separate filing that one month after a third injection, levels of neutralizing antibodies against the Delta variant were about five to seven times as high as they were a month after the second dose.Whatever the Food and Drug Administration decides, it should clearly and publicly explain its reasoning, said Dr. Joshua Sharfstein, a vice dean at the Johns Hopkins Bloomberg School of Public Health and a former principal deputy commissioner of the agency.“F.D.A. does the best in situations when there are strongly held but conflicting views, when they’re forthcoming with the data and really explain decisions,” he said. “It’s important for the F.D.A. not to say, ‘Here’s our decision, mic drop.’”He added, “It’s much better for them to say, ‘Here’s how we looked at the data, here are the conclusions we made from the data, and here’s why we’re making the conclusions.’”Isabel Kershner

Federal regulators warned on Thursday they may not have enough data to recommend boosters for anyone except certain recipients of the Pfizer vaccine by late September.WASHINGTON — Top federal health officials have told the White House to scale back a plan to offer coronavirus booster shots to the general public later this month, saying that regulators need more time to collect and review all the necessary data, according to people familiar with the discussion.Dr. Janet Woodcock, the acting commissioner of the Food and Drug Administration, and Dr. Rochelle P. Walensky, who heads the Centers for Disease Control and Prevention, warned the White House on Thursday that their agencies may be able to determine in the coming weeks whether to recommend boosters only for recipients of the Pfizer-BioNTech vaccine — and possibly just some of them to start.The two health leaders made their argument in a meeting with Jeffrey D. Zients, the White House pandemic coordinator. Several people who heard about the session said it was unclear how Mr. Zients responded. But he has insisted for months that the White House will always follow the advice of government scientists, wherever it leads.Asked about the meeting, a White House spokesman on Friday said, “We always said we would follow the science, and this is all part of a process that is now underway,” adding that the administration was awaiting a “full review and approval” of booster shots by the F.D.A. as well as a recommendation from the C.D.C.“When that approval and recommendation are made,” the spokesman, Chris Meagher, said, “we will be ready to implement the plan our nation’s top doctors developed so that we are staying ahead of this virus.”Less than three weeks ago, Mr. Biden said that contingent on F.D.A. approval, the government planned to start offering boosters the week of Sept. 20 to adults who had received their second shot of the Pfizer-BioNTech or Moderna vaccine at least eight months ago. That would include many health care workers and nursing home residents, as well as some people older than 65, who were generally the first to be vaccinated. Administration officials have said that recipients of the single-dose Johnson & Johnson vaccine would probably be offered an additional shot soon as well.Mr. Biden cast the strategy as another tool that the nation needed to battle the highly contagious Delta variant, which has driven up infection rates, swamped hospitals with Covid-19 patients and is now leading to an average of more than 1,500 deaths a day. “The plan is for every adult to get a booster shot eight months after you got your second shot,” he said on Aug. 18, adding, “It will make you safer, and for longer. And it will help us end the pandemic faster.”Like Mr. Biden, members of his pandemic response team have said that the plan depended on the F.D.A. and the C.D.C. authorizing the booster shots. Both Dr. Woodcock and Dr. Walensky publicly endorsed the strategy, as did the nation’s other senior health leaders.Privately, Dr. Woodcock had argued that it was risky to set a firm date for a booster rollout before regulators had a chance to thoroughly review the data, some of which had yet to be submitted by the vaccine manufacturers, and decide whether shots were safe and necessary, according to several people familiar with the discussions.And since the White House announced the booster plan in mid-August, they said, new hurdles appeared.Among the reasons for delaying is that regulators need more time to decide the proper dosage for a possible third Moderna shot. The company’s application asking the F.D.A. to authorize a booster shot contains insufficient data, one federal official familiar with the process said. Other data expected from Johnson & Johnson has not been delivered.Nor has the raw data that the F.D.A. has been seeking from Israel, which is already giving boosters to everyone 12 and older. Israeli officials say their data shows that the potency of Pfizer’s vaccine wanes over time against severe disease and hospitalization, but that a third shot bolsters protection significantly. The F.D.A. wants to see the underlying data, to make sure it backs up summaries that the Israeli government has provided.Dr. Janet Woodcock, the acting commissioner of the Food and Drug Administration, has privately argued that setting a firm date for booster shots to begin was risky.Stefani Reynolds for The New York TimesNarrowing the booster plan could confuse the public and create a perception that federal vaccine policy is in some degree of disarray. But some public health experts will most likely welcome it.They have been arguing strenuously that the administration lacks the data to justify a broad rollout of extra shots and should instead concentrate on vaccinating the roughly 25 percent of Americans who are eligible for shots but remain unprotected. And some have said that Biden aides wrongly cornered regulators by announcing a strategy before they could conduct a full review..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-3btd0c{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:1rem;line-height:1.375rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-3btd0c{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-3btd0c strong{font-weight:600;}.css-3btd0c em{font-style:italic;}.css-w739ur{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-w739ur{font-size:1.25rem;line-height:1.4375rem;}}.css-9s9ecg{margin-bottom:15px;}.css-16ed7iq{width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:10px 0;background-color:white;}.css-pmm6ed{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}.css-pmm6ed > :not(:first-child){margin-left:5px;}.css-5gimkt{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.8125rem;font-weight:700;-webkit-letter-spacing:0.03em;-moz-letter-spacing:0.03em;-ms-letter-spacing:0.03em;letter-spacing:0.03em;text-transform:uppercase;color:#333;}.css-5gimkt:after{content:’Collapse’;}.css-rdoyk0{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-eb027h{max-height:5000px;-webkit-transition:max-height 0.5s ease;transition:max-height 0.5s ease;}.css-6mllg9{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;position:relative;opacity:0;}.css-6mllg9:before{content:”;background-image:linear-gradient(180deg,transparent,#ffffff);background-image:-webkit-linear-gradient(270deg,rgba(255,255,255,0),#ffffff);height:80px;width:100%;position:absolute;bottom:0px;pointer-events:none;}.css-uf1ume{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;}.css-wxi1cx{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-self:flex-end;-ms-flex-item-align:end;align-self:flex-end;}.css-12vbvwq{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-12vbvwq{padding:20px;width:100%;}}.css-12vbvwq:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-12vbvwq{border:none;padding:10px 0 0;border-top:2px solid #121212;}.css-12vbvwq[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-12vbvwq[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-12vbvwq[data-truncated] .css-5gimkt:after{content:’See more’;}.css-12vbvwq[data-truncated] .css-6mllg9{opacity:1;}.css-qjk116{margin:0 auto;overflow:hidden;}.css-qjk116 strong{font-weight:700;}.css-qjk116 em{font-style:italic;}.css-qjk116 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:visited{color:#326891;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:hover{-webkit-text-decoration:none;text-decoration:none;}Regulators are only beginning to review critical data that will help them determine if and how boosters should be given. Pfizer completed its booster application to the F.D.A. last week, officials said, and Moderna has just initiated its own.This week, two of the F.D.A.’s top vaccine regulators announced that they would be leaving the agency this fall, apparently partly because of frustration with the administration’s booster plan. Dr. Marion Gruber, who directs the agency’s vaccines office, and her deputy, Dr. Philip Krause, have told people there was not nearly enough data to justify offering extra shots to the general population starting in just weeks.More friction may lie ahead. On Sept. 17, the F.D.A.’s outside advisory committee is scheduled to publicly review Pfizer’s data supporting a booster shot. Even though Pfizer has asked the F.D.A. to approve booster doses for people 16 and up, the agency could decide to restrict who gets a booster. The C.D.C. and its outside advisory panel would also have to weigh in.One key member of the F.D.A.’s advisory panel, Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, argues boosters are premature. “There is no compelling reason to get a third dose” now, he said in an interview on Thursday.He said the administration had appeared to expect that the F.D.A. and the C.D.C. would rubber-stamp its booster timeline. “Bypassing and marginalizing those agencies led veterans who you need in this pandemic to leave the F.D.A.,” he said, referring to the departures of Dr. Gruber and Dr. Krause.Various studies have shown that the potency of the Pfizer-BioNTech and Moderna vaccines ebbs against infection over time, but suggest that the vaccines continue to offer robust protection against severe illness and hospitalization.But Dr. Vivek Murthy, the surgeon general, said in an interview on Thursday that a few studies have suggested a dip in protection against severe disease over time. “Our feeling was that if we waited several more months we would see protection against hospitalizations and deaths break down,” he said.In an interview published Thursday on WebMD.com, Dr. Woodcock echoed that view, saying that the trend of breakthrough infections has led health officials to believe at some point, “we are going to see hospitalizations and more serious disease” among fully vaccinated people. When that happens, she said, “we want to be ready” with the booster plan.Some Americans are already getting booster shots ahead of F.D.A. approval: more than a million fully vaccinated people have received an additional dose since mid-August.

The move was expected to kick off a round of new vaccination mandates from hospitals, schools and private companies.WASHINGTON — The Food and Drug Administration on Monday granted full approval to Pfizer-BioNTech’s coronavirus vaccine for people 16 and older, a decision that is likely to set off a cascade of vaccine requirements by hospitals, colleges and universities, corporations and other organizations.Within hours, the Pentagon, CVS, the State University of New York system and the New York City school system, among others, announced that they would enforce mandates they had prepared but made contingent on the F.D.A.’s action.The approval came as the nation’s fight against the pandemic has intensified again, with the highly infectious Delta variant biting deeply into the progress that the country had made over the first half of the year. The Biden administration hopes the development will motivate at least some of the roughly 85 million Americans who are eligible for shots but have so far rejected them to change their minds.The regulatory move goes a step beyond the emergency use authorization that the agency granted in December. More than 92 million people have already been fully vaccinated since then with Pfizer doses. Some who have rejected the vaccines, expressing fears that they are experimental, have said they wanted to wait until the agency spent more time studying their safety and fully approved them.In a roughly 10-minute address on the approval, President Biden said it should sweep away any lingering doubts about vaccines and spur more mandates. Appealing to corporate, state and local leaders, he said: “Do what I did last month. Require your employees to get vaccinated or face strict requirements.” In late July, he announced that all federal employees and on-site contractors must be vaccinated against the coronavirus or be required to submit to regular testing and other measures.Mr. Biden tried to cast the F.D.A. approval as an example of how his administration was making headway against the pandemic, despite overflowing intensive care units in some states and an average of more than 1,000 lives a day lost. He said the death toll, while rising, was still far lower than it was last winter, because more than nine in ten older Americans are now vaccinated.With the F.D.A. yet to authorize a vaccine even on an emergency basis for children younger than 12, Mr. Biden also tried to reassure anxious parents about the growing number of children who are getting infected with the Delta variant, saying that severe Covid-19 cases in that age group are still “very, very rare.” He also promised to soon address “how we get our kids back to school safely.”President Biden said the approval should sweep away any lingering doubts about whether the vaccine is safe and effective.Doug Mills/The New York TimesThe F.D.A., which has been under pressure to speed up its evaluations of coronavirus vaccines, gave full approval to Pfizer’s just 97 days after the company submitted the last of what regulators said were hundreds of thousands of documents. Officials said they were able to decide the matter in less than half the usual time because regulators worked nights and weekends and added staff members, not because they cut corners.“This is a pivotal moment for our country in the fight against the pandemic,” Dr. Janet Woodcock, the acting F.D.A. commissioner, told reporters. “The public can be confident that this vaccine meets the F.D.A.’s gold standard for safety, effectiveness, and manufacturing quality that we require for an approved product.”Some health experts are worried that the approval will unleash a wave of demands from vaccine recipients who want their doctors to prescribe booster doses. The federal government plans to begin rolling out third shots to people who had their second shot eight months earlier, but only after the F.D.A. clears extra doses and not until Sept. 20.“I think we just have to keep people calm,” said Dr. Jesse L. Goodman, a former chief scientist at the F.D.A. and now a medical professor at Georgetown University. He noted that more than one million Americans had already managed to get extra shots on their own and that demand could be difficult to control.Ordinarily, final approval could give doctors a certain measure of freedom to prescribe a drug differently than the label advises. Pfizer is also ostensibly now free to market the vaccine, under the brand name Comirnaty.In this case, though, as both Pfizer and the F.D.A. noted, the federal government controls the distribution of the vaccine in the United States. Dr. Woodcock strongly discouraged people from seeking a third shot until the F.D.A. has ruled on whether extra shots are safe and effective for the general adult population.She specifically warned against giving the vaccine to children under 12, saying that doing so would be “of great concern” because regulators have not collected enough data yet from clinical trials on safety or the proper dose. Trials are still in progress for that age group, and a regulatory decision about emergency use could be several months away.“We certainly want to make sure that we get it right in the children ages 5 through 11,” said Dr. Peter Marks, the F.D.A.’s top vaccine regulator, “and then even in younger children after that.”The vaccine is still authorized for emergency use, instead of fully approved, for children 12 to 15.Pfizer said it presented the F.D.A. with data from 44,000 clinical trial participants — half of whom got the vaccine, the other half a placebo — in the United States, the European Union, Turkey, South Africa and South America. The F.D.A. said the data showed the vaccine was 91 percent effective in preventing disease. That was a slight drop from the 95 percent efficacy rate in December, when the vaccine was cleared for emergency use. Pfizer said the decrease reflected the fact that researchers had more time to catch people who became sick.Some public health experts were hopeful that the decision could push some of those hesitant about getting vaccinated off the fence.Even if only 5 percent more Americans were persuaded to get shots, as some experts have predicted, “that’s still a huge slice of people,” said Dr. Thomas Dobbs, the chief health officer for Mississippi. Like a number of other Southern states, his has been ravaged by the Delta variant. He said licensure would help “shake loose this false assertion that the vaccines are an ‘experimental’ thing.”A recent poll by the Kaiser Family Foundation, which has been tracking public attitudes during the pandemic, found that three of every 10 unvaccinated people said they would be more likely to get vaccinated with a shot that had been fully approved. But the pollsters and other experts warned that far fewer Americans might actually be swayed by the approval.“I think that is a vanishingly small number of people in real life” who would change their minds because of the vaccine’s regulatory status, said Alison Buttenheim, an associate professor of nursing at the University of Pennsylvania and an expert on vaccine hesitancy. But if full approval spurs more requirements from employers and other organizations, she said, the results could be more significant.“We still have a lot of people who just haven’t gotten around to it or don’t have huge objections, but no one’s told them they have to” get vaccinated, she said. “Mandates simplify things for people.”Already on Monday, the Pentagon announced that the country’s 1.4 million active-duty troops would have to be vaccinated, and Gov. Philip D. Murphy of New Jersey said that all teachers in that state would have to get shots or submit to weekly testing. Chevron and CVS both said they would require some of their employees to receive coronavirus vaccines, and the State University of New York and the University of Minnesota systems announced similar requirements for students.Wall Street rose, with investors buoyed by the vaccine news. The S&P 500 stock index was up almost 1 percent, and shares of Pfizer climbed 2.5 percent..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-3btd0c{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:1rem;line-height:1.375rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-3btd0c{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-3btd0c strong{font-weight:600;}.css-3btd0c em{font-style:italic;}.css-w739ur{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-w739ur{font-size:1.25rem;line-height:1.4375rem;}}.css-9s9ecg{margin-bottom:15px;}.css-16ed7iq{width:100%;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;-webkit-box-pack:center;-webkit-justify-content:center;-ms-flex-pack:center;justify-content:center;padding:10px 0;background-color:white;}.css-pmm6ed{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;}.css-pmm6ed > :not(:first-child){margin-left:5px;}.css-5gimkt{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:0.8125rem;font-weight:700;-webkit-letter-spacing:0.03em;-moz-letter-spacing:0.03em;-ms-letter-spacing:0.03em;letter-spacing:0.03em;text-transform:uppercase;color:#333;}.css-5gimkt:after{content:’Collapse’;}.css-rdoyk0{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;-webkit-transform:rotate(180deg);-ms-transform:rotate(180deg);transform:rotate(180deg);}.css-eb027h{max-height:5000px;-webkit-transition:max-height 0.5s ease;transition:max-height 0.5s ease;}.css-6mllg9{-webkit-transition:all 0.5s ease;transition:all 0.5s ease;position:relative;opacity:0;}.css-6mllg9:before{content:”;background-image:linear-gradient(180deg,transparent,#ffffff);background-image:-webkit-linear-gradient(270deg,rgba(255,255,255,0),#ffffff);height:80px;width:100%;position:absolute;bottom:0px;pointer-events:none;}.css-uf1ume{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;}.css-wxi1cx{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-self:flex-end;-ms-flex-item-align:end;align-self:flex-end;}.css-12vbvwq{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-12vbvwq{padding:20px;width:100%;}}.css-12vbvwq:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-12vbvwq{border:none;padding:10px 0 0;border-top:2px solid #121212;}.css-12vbvwq[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-12vbvwq[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-12vbvwq[data-truncated] .css-5gimkt:after{content:’See more’;}.css-12vbvwq[data-truncated] .css-6mllg9{opacity:1;}.css-qjk116{margin:0 auto;overflow:hidden;}.css-qjk116 strong{font-weight:700;}.css-qjk116 em{font-style:italic;}.css-qjk116 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:visited{color:#326891;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:hover{-webkit-text-decoration:none;text-decoration:none;}“The full regulatory approval of the Pfizer vaccine created hopes that it may spur additional gains in vaccination rates in the U.S., which would be an economic positive going forward,” said John Canavan, the lead analyst at Oxford Economics.So far, 54 percent of Americans who have been fully inoculated have gotten Pfizer shots. Most of the rest received Moderna’s vaccine, which also requires two doses.Dr. Marks said that federal health agencies would continue to monitor the Pfizer vaccine’s safety. The F.D.A. will also require Pfizer to continue to study the risk of myocarditis, an inflammation of the heart muscle, and pericarditis, an inflammation of the membrane surrounding the heart, in people who get its shot, including long-term outcomes for those who fall ill after vaccination. The F.D.A. in June attached warnings to the Pfizer and Moderna vaccines noting possible increased risk of both conditions after the second dose.Less than two months after it appeared to have curbed the spread of the virus, the United States is averaging around 150,000 new cases a day and more than 90,000 hospitalized Covid-19 patients. Exactly two months ago, before the Delta variant fully took hold, federal health experts said the nation would be highly unlikely to again face a death toll of 1,000 or more people a day. The seven-day average as of Sunday was 1,008 daily deaths, according to a New York Times database.“Full approval could not come at a more important time,” said Dr. Richard Besser, the president of the Robert Wood Johnson Foundation and a former acting director of the Centers for Disease Control and Prevention. He called on schools and businesses to require vaccination before allowing people to congregate indoors.The next major decision looming for the F.D.A. about coronavirus vaccines is whether to authorize booster shots. Saul Martinez for The New York TimesVaccination rates have been rising steadily in recent weeks as fear of the Delta variant has grown. Providers were administering about 837,000 shots a day late last week, and Mr. Biden said the most recent seven-day total was the highest since early July. He said more people in Alabama, Arkansas, Louisiana and Mississippi — some of the states with the highest caseloads — got their first shots in the past month than in the previous two months combined.Dr. Marks said that myths about the vaccines remain a major impediment to fighting the pandemic, including false claims that shots would cause infertility, would foster rather than prevent Covid-19, and had even led to thousands of deaths.“Let me be clear: These claims are simply not true,” he said.The F.D.A. is in the midst of a blizzard of decisions about coronavirus vaccines. The next major one looming is whether to authorize booster shots.The Biden administration said last week it planned to offer third shots to adults who got the Pfizer and Moderna vaccines, eight months after their second injection, starting Sept. 20. Third shots are already authorized for some people with immune deficiencies, but the risk-benefit calculus is different for the general population.Federal health officials said that both Pfizer’s and Moderna’s vaccines, which rely on similar technology, wane in potency over time. That trend, they said, is converging with the rise of the particularly dangerous Delta variant, making those who completed their vaccinations at the start of the year increasingly vulnerable to infection.Some public health experts have challenged the plan for booster shots as premature. They say the available data shows that the vaccines are holding up well against severe disease and hospitalization, including against the Delta variant. Extra shots would be warranted only if the vaccines failed to meet that standard, some have said.Regulators are still reviewing Moderna’s application for full approval of its vaccine, which it filed in June, a month after Pfizer. That decision could take several weeks. Johnson & Johnson is expected to apply for full approval soon.Susan C. Beachy

The Food and Drug Administration’s move is expected to kick off more vaccination mandates for hospital workers, college students and federal troops.WASHINGTON — With a new surge of Covid-19 infections ripping through much of the United States, the Food and Drug Administration has accelerated its timetable to fully approve Pfizer-BioNTech’s coronavirus vaccine, aiming to complete the process by the start of next month, people involved in the effort said.President Biden said last week that he expected a fully approved vaccine in early fall. But the F.D.A.’s unofficial deadline is Labor Day or sooner, according to multiple people familiar with the plan. The agency said in a statement that its leaders recognized that approval might inspire more public confidence and had “taken an all-hands-on-deck approach” to the work.Giving final approval to the Pfizer vaccine — rather than relying on the emergency authorization granted late last year by the F.D.A. — could help increase inoculation rates at a moment when the highly transmissible Delta variant of the virus is sharply driving up the number of new cases.A number of universities and hospitals, the Defense Department and at least one major city, San Francisco, are expected to mandate inoculation once a vaccine is fully approved. Final approval could also help mute misinformation about the safety of vaccines and clarify legal issues about mandates.Federal regulators have been under growing public pressure to fully approve Pfizer’s vaccine ever since the company filed its application on May 7. “I just have not sensed a sense of urgency from the F.D.A. on full approval,” Dr. Ashish K. Jha, the dean of the Brown University School of Public Health, said in an interview on Tuesday. “And I find it baffling, given where we are as a country in terms of infections, hospitalizations and deaths.”Although 192 million Americans — 58 percent of the total population and 70 percent of the nation’s adults — have received at least one vaccine shot, many remain vulnerable to the ultracontagious, dominant Delta variant. The country is averaging nearly 86,000 new infections a day, an increase of 142 percent in just two weeks, according to a New York Times database.Recent polls by the Kaiser Family Foundation, which has been tracking public attitudes during the pandemic, have found that three of every 10 unvaccinated people said that they would be more likely to get a shot with a fully approved vaccine. But the pollsters warned that many respondents did not understand the regulatory process and might have been looking for a “proxy” justification not to get a shot.Moderna, the second most widely used vaccine in the United States, filed for final approval of its vaccine on June 1. But the company is still submitting data and has not said when it will finish. Johnson & Johnson, the third vaccine authorized for emergency use, has not yet applied but plans to do so later this year.Full approval of the Pfizer vaccine will kick off a patchwork of vaccination mandates across the country. Like most other employees of federal agencies, civilians working for the Defense Department must be vaccinated or face regular testing. But the military has held off on ordering shots for 1.3 million active-duty service members until the F.D.A. acts.The City of San Francisco has said its roughly 44,500 employees must be fully vaccinated within 10 weeks of F.D.A. approval. The State University of New York, with roughly 400,000 students, is on a parallel track.A number of health care systems have issued similar mandates to employees, including Beaumont Health, the largest health provider in Michigan, with 33,000 employees, and Mass General Brigham in Massachusetts, with about 80,000 workers.Full approval typically requires the F.D.A. to review hundreds of thousands of pages of documents — roughly 10 times the data required to authorize a vaccine on an emergency basis. The agency can usually complete a priority review within six to eight months and was already working on an expedited timetable for the Pfizer vaccine. The F.D.A.’s decision to speed up was reported last week by Stat News.In a guest essay in The Times last month, Dr. Peter Marks, the agency’s top vaccine regulator, wrote that undue haste “would undermine the F.D.A.’s statutory responsibilities, affect public trust in the agency and do little to help combat vaccine hesitancy.”The regulators want to see real-world data on how the vaccine has been working since they authorized it for emergency use in December. That means verifying the company’s data on vaccine efficacy and immune responses, reviewing how efficacy or immunity might decline over time, examining new infections in participants in continuing clinical trials, reviewing adverse reactions to vaccinations and inspecting manufacturing plants.At the same time, senior health officials at the F.D.A. and other agencies are grappling with whether at least some people who are already vaccinated need booster shots. Several officials are arguing that boosters will be widely needed before long, while others contend that the scientific basis for them remains far from settled.Two people familiar with the deliberations, speaking on the condition of anonymity, said that if booster shots are needed, the administration wants a single strategy for all three vaccines currently authorized for emergency use.Different recommendations on boosters for different vaccines, they said, could confuse the public. Fully approving a vaccine and then authorizing a booster for it soon after might also offer conflicting messages about its effectiveness..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-3btd0c{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:1rem;line-height:1.375rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-3btd0c{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-3btd0c strong{font-weight:600;}.css-3btd0c em{font-style:italic;}.css-w739ur{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-w739ur{font-size:1.25rem;line-height:1.4375rem;}}.css-9s9ecg{margin-bottom:15px;}.css-uf1ume{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;}.css-wxi1cx{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-self:flex-end;-ms-flex-item-align:end;align-self:flex-end;}.css-12vbvwq{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-12vbvwq{padding:20px;width:100%;}}.css-12vbvwq:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-12vbvwq{border:none;padding:10px 0 0;border-top:2px solid #121212;}.css-12vbvwq[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-12vbvwq[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-12vbvwq[data-truncated] .css-5gimkt:after{content:’See more’;}.css-12vbvwq[data-truncated] .css-6mllg9{opacity:1;}.css-qjk116{margin:0 auto;overflow:hidden;}.css-qjk116 strong{font-weight:700;}.css-qjk116 em{font-style:italic;}.css-qjk116 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:visited{color:#326891;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:hover{-webkit-text-decoration:none;text-decoration:none;}While research is continuing, senior administration officials increasingly believe that at the least, vulnerable populations like those with compromised immune systems and older people will need them, according to people familiar with their thinking. But when to administer them, which vaccine to use and who should get shots are all still being discussed.In a study posted online last week, Pfizer and BioNTech scientists reported that the effectiveness of Pfizer’s vaccine against symptomatic disease fell from about 96 percent to about 84 percent four to six months after the second shot, but continued to offer robust protection against hospitalization and severe disease.Administration officials said Moderna and Johnson & Johnson needed to present data as well and Moderna had been asked to do so quickly. Officials have said other studies will also influence their decision-making, including data that the government is collecting on the rate of breakthrough infections among tens of thousands of people, including health care workers.Pfizer is expected to submit an application for a booster shot to the F.D.A. this month. While the F.D.A. could authorize such shots, the Centers for Disease Control and Prevention would need to recommend them after a meeting of its outside committee of experts.A decision to fully approve Pfizer’s vaccine will give doctors more latitude to prescribe additional shots at least for certain Americans, including those with weakened immune systems. The C.D.C. had been exploring possible special programs for that group, but administration officials said it became clear that by the time any such initiative got underway, the Pfizer vaccine would already be fully approved and doctors could prescribe a third shot.Roughly 3 percent of Americans — or about 10 million people, by some estimates — have compromised immune systems as a result of cancer, organ transplants or other medical conditions, according to the C.D.C. While studies indicate that the vaccines work well for some of them, others do not produce the immune response that would protect them from the virus.Some people are trying to get booster shots from pharmacies or other providers on their own, without waiting for the federal government’s blessing. Officials in Contra Costa County, home to 1.1 million people in Northern California, were so eager to offer boosters that on July 23 they told vaccine providers to give extra shots to people who asked for them “without requiring further documentation or justification.”Then, realizing that policy violated the F.D.A. rules on vaccines authorized for emergency use, the county reversed it this week.Jennifer Steinhauer

The move brings the total number of Johnson & Johnson doses made at the troubled plant and cleared by the F.D.A. to roughly 40 million.WASHINGTON — Federal regulators on Friday cleared a batch of vaccine that could furnish up to 15 million doses of Johnson & Johnson’s one-shot coronavirus vaccine, deciding they can be safely distributed despite production failures at the factory that ruined 75 million other doses.The move brings the total number of Johnson & Johnson doses made at the Baltimore facility and cleared by the Food and Drug Administration for distribution in the United States to roughly 40 million. But Johnson & Johnson remains far short of its commitment to deliver 100 million doses to the federal government by the end of June. European Union officials have said the company is missing its delivery targets there, as well.The vaccine cleared on Friday is not yet bottled, and the Biden administration’s plans for it remain unclear. But with new coronavirus cases dropping and the country awash in vaccines from two other authorized manufacturers, most new Johnson & Johnson doses produced in the United States are likely destined for export.Johnson & Johnson has been unable to produce much of its vaccine since April, when regulators shut down the Baltimore factory, operated by Emergent BioSolutions, because of major production errors. Johnson & Johnson had been relying on Emergent, its subcontractor, to produce vaccine for use in the United States as well as to meet its commitments overseas while it expanded its own plant in Leiden, the Netherlands.Even with the newly cleared batch, Johnson & Johnson remains nearly 40 million doses short of the 100 million doses called for in its federal contract. The F.D.A. did not disclose the precise number of doses cleared Friday, but multiple people familiar with Emergent’s operation said the batch amounted to as many as 15 million doses.Also on Friday, European regulators approved the reopening of Johnson & Johnson’s Dutch plant, a piece of good news for the company amid its supply woes. “Today’s approval represents progress in expanding our global manufacturing network to supply our Covid-19 vaccine worldwide,” the company said in a statement.The Baltimore factory is expected to remain shuttered for at least several more weeks while Emergent tries to bring it up to standard, according to people familiar with its operation who spoke on condition of anonymity. The F.D.A. said in a statement Friday that it was not yet ready to certify that the plant was following proper manufacturing practices.After the discovery in March that Emergent workers had contaminated a batch of Johnson & Johnson’s vaccine with a key ingredient for AstraZeneca’s Covid vaccine being made at the same plant, regulators cited Emergent for a series of regulatory violations. Emergent was forced to throw out the equivalent of 75 million doses of Johnson & Johnson vaccine. European authorities discarded another 17 million more doses, and South Africa, which is desperate for vaccine, pulled two million more.The Biden administration also had to pivot from relying on AstraZeneca doses to fulfill its pledge to donate vaccine to poorer nations, swapping in supplies from other makers. The F.D.A. has yet to rule on whether the equivalent of more than 100 million doses of both Johnson & Johnson and AstraZeneca vaccines produced by Emergent are suitable for use.The F.D.A. has been conducting a painstaking review of every vaccine batch from the Emergent plant, matching up records of deviations from manufacturing standards with production lots to determine whether the batches can be released. In a letter to Johnson & Johnson released late Friday, the agency said the batch it was releasing was suitable for distribution even though the factory was not adhering to proper manufacturing practices at the time it was produced.As deliveries of Johnson & Johnson’s vaccine stalled, the Biden administration ended up relying almost entirely on doses made by Pfizer-BioNTech and Moderna. With the pandemic now waning in the United States, demand for shots has plummeted. Johnson & Johnson has teamed up with the pharmaceutical giant Merck to make more doses, but the factory they intend to use is not expected to start operating until the fall.Although the Johnson & Johnson vaccine was once considered a game changer in the nation’s vaccination campaign, state health officials have struggled to use up even the limited supply they received in the spring. Roughly 12.5 million people in the United States have taken the vaccine, accounting for a little more than half of the available supply, and millions of doses are set to expire by August. It is still being used in doctors’ offices and at smaller events, state officials said.Enthusiasm for the Johnson & Johnson vaccine dropped in part because of a federally recommended pause in its use in April after a rare blood-clotting disorder was discovered in a few recipients.But federal health officials are still hoping that surplus doses of Johnson & Johnson’s vaccine will be useful overseas, where vaccine doses remain desperately scarce. White House officials said this week that some countries had requested the vaccine because it is easier to store and transport than the others, and because some people prefer a one-shot regimen. The vaccine has been deployed in 27 countries so far.On Thursday, Johnson & Johnson reported that early results of unpublished studies showed that its vaccine was effective against the highly contagious Delta variant, even eight months after inoculation. That was a reassuring finding for those who have gotten the company’s shot.The news came after earlier data showed Pfizer’s and Moderna’s mRNA vaccines as effective against the Delta variant, which is much more contagious than previous variants and is expected to quickly become the dominant version of the virus in the United States. Because Johnson & Johnson’s vaccine rolled out more slowly, information about its effectiveness against variants has also lagged.