WASHINGTON — The Biden administration moved on multiple fronts on Wednesday to fight back against the surging Delta variant, strongly recommending booster shots for most vaccinated American adults and using federal leverage to force nursing homes to vaccinate their staffs.
In remarks from the East Room of the White House, President Biden also directed his education secretary to “use all of his authority, and legal action if appropriate,” to deter states from banning universal masking in classrooms. That move is destined to escalate a fight with some Republican governors who are blocking local school districts from requiring masks to protect against the virus.
The shifts in strategy reflect the administration’s growing concern that the highly contagious Delta variant is erasing its hard-fought progress against the pandemic and thrusting the nation back to the more precarious point it was at earlier in the year.
Thus far, Mr. Biden has been reluctant to use the federal government’s power to withhold funding as a means of fighting the pandemic. But that changed Wednesday, when he said his administration would make employee vaccination a condition for nursing homes to receive Medicare and Medicaid funding. Officials said the decision would affect more than 15,000 nursing homes that employ 1.3 million workers.
“The threat of the Delta virus remains real, but we are prepared, we have the tools, we can do this,” Mr. Biden said in the East Room, adding, “This is no time to let our guard down.”
He accused politicians who were banning local school districts from requiring masks in the classroom of setting a “dangerous tone,” adding, “We’re not going to sit by as governors try to block and intimidate educators from protecting our children.” The administration is sending letters to eight states — Arizona, Florida, Iowa, Oklahoma, South Carolina, Tennessee, Texas and Utah — challenging their efforts to ban universal masking in schools.
For many Americans, the booster strategy will affect them the most. The government plans to offer third shots to adults who received the Pfizer-BioNTech or Moderna vaccines eight months after they received their second dose. About 150 million Americans have been fully immunized with one of those two vaccines.
“We are concerned that the current strong protection against severe infection, hospitalization and death could decrease in the months ahead, especially among those who are at higher risk” or who were inoculated in the early months of the vaccination campaign, Dr. Rochelle P. Walensky, the director of the Centers for Disease Control and Prevention, said.
Assuming that regulators decide third shots are safe and effective, the effort will start Sept. 20. Officials said they were waiting on more data to decide whether the 14 million Americans who received Johnson & Johnson’s single-dose vaccine should also receive an additional shot, but suggested that they would be included as well.
Although some public health experts have said booster shots were prudent and expected, not all scientists are convinced it is the right move. And advocates for global health said it was morally wrong — and shortsighted — for the administration to give booster shots to Americans when so many people around the world were still waiting to be vaccinated.
For state officials and health care providers, already exhausted from an 18-month battle against a novel virus that seems to shift its shape the moment it seems under control, the booster-vaccination campaign will bring a fresh round of logistical challenges. Some worried it could sidetrack efforts to vaccinate the roughly 85 million Americans who were eligible for shots but remained unvaccinated.
“We now have to fight a war on two fronts,” said Dr. José R. Romero, the Arkansas secretary of health. “We have to continue to press the vaccine into those groups that have not accepted it, and then have another effort to vaccinate those at high risk.”
The move to make employee vaccination a condition for nursing homes to receive Medicare and Medicaid funding reflects months of frustration with the low vaccination rates among nursing assistants and other workers who care for highly vulnerable people.
Officials described it as the first time that Mr. Biden had threatened to withhold federal funding in order to force vaccinations.
In an interview before the president spoke, Education Secretary Miguel A. Cardona described another major turning point: his department will use its civil rights enforcement arm to allow schools to require masks. The move comes as many educators and parents fear a surge in cases as the school year is about to start and as pediatric Covid cases climb.
The C.D.C. has recommended that everyone in schools wears masks, regardless of their vaccination status, but some states and localities are refusing to issue rules requiring masks or preventing schools from imposing them.
“The president is appalled, as I am, that there are adults who are blind to their blindness, that there are people who are putting policies in place that are putting students and staff at risk,” Dr. Cardona said in the interview.
“At the end of the day,” he said, “we shouldn’t be having this conversation. What we’re dealing with now is negligence.”
Administration officials made clear that booster shots would depend upon a determination by the Food and Drug Administration that third shots are safe and effective — a ruling expected in the coming weeks. Whether those under the age of 18 will be eligible will also be up to the F.D.A. and a federal advisory committee of experts, they said.
Aside from some people with weakened immune systems who have already been authorized for third shots, officials advised that fully vaccinated people wait for what they promised would be a speedy but orderly national rollout of booster shots.
“Here’s what you need to know: If you are fully vaccinated, you still have a high degree of protection from the worst outcomes of Covid-19 — severe disease, hospitalization and death,” Dr. Vivek H. Murthy, the surgeon general, said at a White House briefing. “We are not recommending that you go out and get a booster today.”
Dr. Walensky presented a series of studies at the briefing that, she said, showed the vaccines’ efficacy wanes over time. Some doctors applauded the decision to offer booster shots.
“Given the prevalence we have of the Delta variant, doing everything we can to keep people out of the hospital — especially those at high risk — does make sense,” said Dr. Paul Biddinger, the director of the Center for Disaster Medicine at Massachusetts General Hospital.
But some scientists criticized the policy as overly broad, arguing that it is not clear that the general population needs a third shot.
Jennifer B. Nuzzo, an epidemiologist at Johns Hopkins University’s Bloomberg School of Public Health, said the studies cited by administration officials showed that the vaccines were doing what they were intended to do — protect against severe disease and hospitalization.
“I don’t think the metric of, ‘We’re seeing more infection’ is the right metric to be judging the efficacy of the vaccines,” she said. “The right metric is, ‘Does it prevent severe disease?’ ”
The administration’s move follows similar actions by Israel, Germany and France but goes against the recommendation of the World Health Organization, which is arguing extra vaccine supply should go to countries that have vaccinated far fewer of their residents.
“Vaccine injustice is a shame on all humanity and if we don’t tackle it together, we will prolong the acute stage of this pandemic for years when it could be over in a matter of months,” Dr. Tedros Adhanom Ghebreyesus, the organization’s director general, said at a news conference before the White House’s briefing.
Jeffrey D. Zients, the White House pandemic coordinator, said the administration was already donating 600 million doses of vaccines to needy countries and would continue that effort — a point Mr. Biden reiterated in the East Room.
“We can take care of America and help the world at the same time,” Mr. Biden said.
Administration experts said the booster policy was the result of dual, disturbing trends: a decline in the vaccines’ potency over time and the apparent ability of the Delta variant to somehow bypass their protection better than its predecessors.
One study they cited found the vaccines’ effectiveness at preventing infections among nursing home residents dropped to about 53 percent from 75 percent between spring and summer, when the Delta variant became dominant.
Understand the State of Vaccine and Mask Mandates in the U.S.
- Mask rules. The Centers for Disease Control and Prevention in July recommended that all Americans, regardless of vaccination status, wear masks in indoor public places within areas experiencing outbreaks, a reversal of the guidance it offered in May. See where the C.D.C. guidance would apply, and where states have instituted their own mask policies. The battle over masks has become contentious in some states, with some local leaders defying state bans.
- Vaccine rules . . . and businesses. Private companies are increasingly mandating coronavirus vaccines for employees, with varying approaches. Such mandates are legally allowed and have been upheld in court challenges.
- College and universities. More than 400 colleges and universities are requiring students to be vaccinated against Covid-19. Almost all are in states that voted for President Biden.
- Schools. On Aug. 11, California announced that it would require teachers and staff of both public and private schools to be vaccinated or face regular testing, the first state in the nation to do so. A survey released in August found that many American parents of school-age children are opposed to mandated vaccines for students, but were more supportive of mask mandates for students, teachers and staff members who do not have their shots.
- Hospitals and medical centers. Many hospitals and major health systems are requiring employees to get a Covid-19 vaccine, citing rising caseloads fueled by the Delta variant and stubbornly low vaccination rates in their communities, even within their work force.
- New York. On Aug. 3, Mayor Bill de Blasio of New York announced that proof of vaccination would be required of workers and customers for indoor dining, gyms, performances and other indoor situations, becoming the first U.S. city to require vaccines for a broad range of activities. City hospital workers must also get a vaccine or be subjected to weekly testing. Similar rules are in place for New York State employees.
- At the federal level. The Pentagon announced that it would seek to make coronavirus vaccinations mandatory for the country’s 1.3 million active-duty troops “no later” than the middle of September. President Biden announced that all civilian federal employees would have to be vaccinated against the coronavirus or submit to regular testing, social distancing, mask requirements and restrictions on most travel.
Dr. Walensky said preliminary data from another study of more than 4,000 frontline workers suggested that the vaccines might not work as well against the Delta variant than against prior variants. In that study, a decline in vaccine efficacy against infection appeared related to the variant, not to how long ago the workers were vaccinated, she said.
She also cited data from Israel showing a worsening in the infection rate among vaccinated people over time. Israel vaccinated much of its population faster than other countries, making it a potential harbinger of what is to come for the United States.
Dr. Murthy said there was “nothing magical” about the eight-month timeline for allowing boosters, describing it simply as the best judgment of health experts. He and other officials emphasized that the overwhelming majority of hospitalizations and deaths from Covid continued to occur among the unvaccinated.
“Protection against severe disease and hospitalization is currently holding up pretty well,” Dr. Walensky said.
First in line for booster shots will be health care workers, nursing home residents and other older adults, followed by the rest of the general population. Officials envision offering the extra shots at pharmacies and other sites where initial vaccinations are already underway, rather than reopening mass vaccination sites. More than five million people could be eligible for the shots as of late September.
Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases and the president’s top medical adviser for the pandemic, said studies had shown that third shots of the Moderna and Pfizer vaccines could boost the levels of antibodies that fight the virus tenfold — an increase he called “remarkable.”
Although they promised the booster rollout would be orderly and thoughtful, federal officials are clearly racing against the clock to offer extra shots before those who were vaccinated earliest could be more vulnerable to the threat of severe disease.
The F.D.A. must first authorize third doses, and an advisory committee of the C.D.C. must review the evidence and make recommendations. But neither Pfizer nor Moderna have yet submitted all the necessary data showing that third shots are safe and effective.
Pfizer is expected to finish submitting its data this month. Moderna and the National Institutes of Health are studying whether a half dose or full dose works best. The company plans to submit its data next month.
On the plus side, federal and state health officials said that much of the infrastructure for a rollout was already in place. Tens of thousands of pharmacies and other sites are already offering shots on a daily basis, and many state officials said they could easily expand their work.
The nation’s vaccine surplus also makes it unlikely that Americans will experience the kind of frenzy seen in the early weeks of the vaccine effort last winter, when older Americans desperate for shots flooded mass vaccination sites. “The bottom line is that we are prepared for boosters, and we will hit the ground running,” Mr. Zients said.
Some state officials sounded less sure of a smooth operation. “It’s hard even to predict how strong the demand will be,” said Dr. Marcus Plescia, the chief medical officer for the Association of State and Territorial Health Officials, which was briefed on the administration’s plans Wednesday morning by C.D.C. experts.
“The big question is, do we do community vaccination clinics again, which worked very well in the initial run,” he said, “or is the demand going to be a little bit more spaced out over time?”
Apoorva Mandavilli and Daniel E. Slotnik contributed reporting.