Just a day after President Biden issued broad mandates aimed at encouraging American workers to get vaccinated against the coronavirus, federal health officials released new data showing that unvaccinated Americans are 11 times as likely as vaccinated people to die of Covid-19.
Three large studies, published on Friday by the Centers for Disease Control and Prevention, also highlighted the effectiveness of the shots at preventing infection and hospitalizations with the virus.
The research underscored a deep conviction among scientists that vaccine hesitancy and refusal have prolonged the pandemic. The administration’s new plan should stem the flood of infections and return the country to some semblance of normalcy in the long term, several experts said in interviews.
“It’s going to fundamentally shift the arc of the current surge,” said Dr. Ashish Jha, dean of Brown University School of Public Health. “It’s exactly what’s needed at this moment.”
The new data also may help bolster confidence in the nation’s vaccines, which has eroded amid unexpected reports of breakthrough infections.
One of the studies looked at more than 600,000 virus infections in 13 states, representing about one quarter of the U.S. population, between April and July. The researchers concluded that Americans who were not fully vaccinated were far more susceptible to infections, illness and death from the virus.
Even after the Delta variant became dominant in the United States over the summer, the vaccines’ protections remained strong: Compared with vaccinated adults, those who were not fully vaccinated were 4.5 times as likely to become infected, 10 times as likely to be hospitalized and 11 times as likely to die of Covid.
The cumulative data have made it clear that the nation cannot hope to end the pandemic with some 37 percent of Americans not having received a single dose of Covid vaccine, researchers said. Cases and hospitalizations are only expected to rise as Americans move indoors into homes, schools and offices in the fall.
That is why scientists generally welcomed the Biden administration’s vigorous vaccination push. Mandatory vaccinations will be crucial for keeping the virus in check as it becomes endemic in the United States, said Natalie Dean, a biostatistician at Emory University in Atlanta: “It’s part of the shift from short-term reactions to long-term solutions.”
Still, some experts cautioned that results from the administration’s plan would take many weeks to unfold. It is not clear when the new requirements will be finalized or how the promised legal challenges from Republicans will play out in courtrooms. Moreover, while the administration said the mandates would cover 100 million American workers, no one knows how many of them have already been vaccinated.
In any event, immunization is not an instant process — at least six weeks for a two-dose vaccine. The administration did not emphasize measures that work more quickly to stop the virus: masking and widespread rapid testing, for example.
The nation will need every tool at its disposal to fend off the Delta variant, a far more formidable foe than the original version of the virus. The variant became the dominant version of the virus in the United States only in mid-July, and the consequences have been beyond anything experts predicted.
Reassuringly low numbers of cases and hospitalizations in June have risen inexorably for weeks to nearly 10 times their previous levels. About 1,500 Americans, the vast majority of them unvaccinated, are dying each day.
Much of the misery could be prevented, the new C.D.C. research found. An analysis of 32,867 patient visits in nine states found that even as the Delta variant predominated, the vaccines had an overall effectiveness rate of 86 percent at preventing hospitalizations, though they were less protective for adults aged 75 and over.
Moderna vaccines had the highest efficacy rate, at 95 percent, compared with 80 percent for Pfizer-BioNTech and 60 percent for the Johnson & Johnson vaccine.
The shots’ effectiveness at preventing infection declined somewhat, from 91 percent to 78 percent, as the variant spread. The Moderna vaccine had an effectiveness rate of 92 percent against infection, compared with 77 percent for the Pfizer-BioNTech shot and 65 percent for Johnson and Johnson.
“There are more breakthrough infections happening than there were before — that’s a real phenomenon,” said Heather Scobie, an epidemiologist at the C.D.C. and lead author of the largest of the studies. “But for the most part, people are not going to hospitals if they’ve been vaccinated.”
The new data show that vaccine mandates will protect millions more people, particularly against severe disease, and will relieve pressure on the health care system, Dr. Dean said. “It also sets a precedent for other organizations to make similar decisions” about mandates, she added.
The administration’s new mandates include health care workers, requiring that any provider receiving Medicaid or Medicare funding impose a vaccination requirement on staff members. This is the measure mostly likely to have an immediate impact, experts said, because health care facilities are high-risk settings for transmission.
There is ample historical precedent for the decision to hold hospitals to certain standards — notably, the historical directive to desegregate patients by race, Dr. Jha said.
“We have a real dearth of leadership from health care systems that have not mandated within their own organizations, and it is imperative that the president require that patients be protected,” he added.
The requirement may drive some health care and nursing home workers, particularly many who are close to retirement age, to leave the profession, and exacerbate staffing shortages. Even so, there is more to be gained than lost by the mandates, said Dr. Nahid Bhadelia, founding director of the Center for Emerging Infectious Diseases Policy and Research at Boston University.
“This is an important step to get us out of the pandemic,” she said. “The very people who are taking care of the vulnerable coming into the hospital need to be our first line of defense.”
The Labor Department will order all private-sector businesses with more than 100 employees to require that their work forces be fully vaccinated or be tested at least once a week. Employers will be required to give paid time off to employees to get vaccinated.
That move alone will affect 80 million Americans. But Bill Hanage, an epidemiologist at Harvard University, was skeptical that the mandates would be successful in inoculating millions more people than have already opted for the vaccine.
Understand Vaccine and Mask Mandates in the U.S.
- Vaccine rules. On Aug. 23, the Food and Drug Administration granted full approval to Pfizer-BioNTech’s coronavirus vaccine for people 16 and up, paving the way for an increase in mandates in both the public and private sectors. Private companies have been increasingly mandating vaccines for employees. Such mandates are legally allowed and have been upheld in court challenges.
- 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.
- 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. Both California and New York City have introduced vaccine mandates for education staff. 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 City. Proof of vaccination is required of workers and customers for indoor dining, gyms, performances and other indoor situations, although enforcement does not begin until Sept. 13. Teachers and other education workers in the city’s vast school system will need to have at least one vaccine dose by Sept. 27, without the option of weekly testing. 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.
Some of the people who most urgently need to be protected are older adults who will not be affected by workplace requirements, he noted. The new C.D.C. research on Friday confirmed that this population was particularly vulnerable.
One study, conducted at five Veterans Affairs medical centers, where patients tend to be burdened by chronic illnesses that contribute to severe Covid disease, found that the vaccines’ protection against hospitalization declined with age, to 80 percent for those aged 65 and older, down from 95 percent for adults aged 18 to 64. A second study found vaccine effectiveness dropped off at age 75.
And mandates already are drawing criticism from conservative Americans. Republican governors in several states have decried the mandates as unconstitutional and say they plan to file suits to stop them.
“My question would be whether this actually makes people get vaccinated, or just increases the political heat around it,” Dr. Hanage said.
More than half of Americans favor vaccine mandates for workplaces, but in a recent poll, 87 percent of those who were unvaccinated said they would not get the shots even if their employers required them.
By insisting that vaccination is the way out of the pandemic, officials in both the Trump and Biden administrations have de-emphasized the importance of masks, testing and ventilation when so many are likely to remain unvaccinated, several experts said.
“There are many measures that were left on the table, such as an indoor mask mandate tied to community transmission rates, or minimum ventilation standards for schools and workplaces,” said Dr. Gavin Yamey, a global health expert at Duke University.
Recently, Dr. Yamey was unable to locate a single Binax rapid test within a 100-mile radius of Durham, N.C. — “which is pathetic,” he said. “I was in England recently, where home antigen tests are free and plentiful.”
Simple and inexpensive tests are crucial for monitoring the rise and fall of the virus, Dr. Bhadelia noted: “If you don’t have eyes on the ground, if you don’t have the lay of the land, you really can’t do any other planning.”
The Occupational and Safety and Health Administration, which regulates workplace safety, will require private businesses to mandate that their employees either be vaccinated or provide weekly proof of a negative test.
But weekly tests are unlikely to be helpful against the Delta variant, because the virus replicates quickly in the airways and an infection swiftly becomes contagious. Businesses in hard-hit areas, at least, should consider testing twice a week, Dr. Bhadelia said.
Many public health experts felt “uneasy” when Americans, urged by the administration, prematurely celebrated a summer of freedom from the virus, she said. But with much of the world still unprotected from the virus, new variants may again surge in the nation.
“We need an honest conversation about the goals of what it means to be on the other side of the pandemic phase of this crisis,” she said. “This is a once-in-a-century pandemic, and we have to course correct — and it’s OK to do that.”