Most new infections in the U.S. continue to be among unvaccinated people. But “breakthrough” infections, which generally cause milder illness, can occur in vaccinated people. When earlier strains of the virus predominated, infected vaccinated people were found to have low levels of virus and were deemed unlikely to spread the virus much, Walensky said.
But with the delta variant, the level of virus in infected vaccinated people is “indistinguishable” from the level of virus in the noses and throats of unvaccinated people, Walensky said.
The data emerged over the last couple of days from 100 samples. It is unpublished, and the CDC has not released it. But “it is concerning enough that we feel like we have to act,” Walensky said, as vaccinated people “have the potential to spread that virus to others,” she said.
Some public health experts said they thought the earlier CDC decision was based on good science, which indicated that the risk of vaccinated people spreading the virus was relatively low and that the risk of them catching the virus and becoming extremely ill was even lower.
“I hope the CDC doesn’t impose a one-size-fits-all approach,” said Dr. Cecil Bennett, a Newnan-based family physician. “It’s hard to imagine how someone who has been fully vaccinated, and now has to wear a mask indoors, will convince someone who has been unvaccinated to become inoculated.
“I worry the CDC is panicking a bit by having to put us all in masks,” he said.
But experts were also critical, noting there was no call for Americans to document their vaccination status, which created an honor system. Unvaccinated people who did not want to wear masks in the first place saw it as an opportunity to do what they wanted, they said.
“If all the unvaccinated people were responsible and wore mask indoors, we would not be seeing this surge,” said Dr. Ali Khan, a former CDC disease investigator who now is dean of the University of Nebraska’s College of Public Health.
Lawrence Gostin, a public health law professor at Georgetown University, drew a similar conclusion.
“It was completely foreseeable that when they (the CDC) made their announcement, masking would no longer be the norm, and that’s exactly what’s happened,” Gostin said.
The CDC may be seen as “flip-flopping,” he said, because there’s been no widely recognized change in the science, he said. Furthermore, it’s not likely to change the behavior of the people who most need to wear masks.
“I don’t think you can effectively walk that back,” he said.
On Monday, the White House reportedly decided the nation’s existing travel restrictions will remain in place for the foreseeable future.
On Tuesday, former President Barack Obama’s CDC director predicted the nation could see up to 200,000 cases over the next month and a half.
“We’re heading into a rough time,” Dr. Tom Frieden told CNN. “It’s likely, if our trajectory is similar to that in the United Kingdom, that we could see as many as 200,000 cases a day.”
Frieden, who was also a commissioner in the New York City Department of Health and Mental Hygiene, added the U.S. likely won’t see the “horrific death tolls” of earlier in the pandemic, but “you will see a steady increase in deaths, and these are preventable deaths.”
Frieden currently serves as president and CEO of Resolve to Save Lives, a $225 million, five-year initiative to prevent epidemics and cardiovascular disease.
On Sunday, President Joe Biden’s top health adviser warned the U.S. is in an “unnecessary predicament” of soaring COVID-19 cases fueled by unvaccinated Americans and the delta variant.
“We’re going in the wrong direction,” said Dr. Anthony Fauci, describing himself as “very frustrated.”
According to the CDC, only 49.1% of the U.S. is vaccinated against the coronavirus. More than 163 million people, or 49% of the total U.S. population, are fully vaccinated, according to CDC data. Of those eligible for the vaccine, ages 12 and over, the figure rises to 57%.
Nationally, 56.4% of all Americans, including children, have received at least one dose of the vaccine, according to the CDC.
White House press secretary Jen Psaki said the delta variant has changed the nation’s COVID-19 outlook since the the CDC relaxed masking recommendations.
“That is their job. Their job is to look at evolving information, evolving data, an evolving historic pandemic and provide guidance to the American public,” Psaki said.
“What has not changed,” she added, “is the fact that people who are vaccinated have a huge deal of protection from serious illness, from hospitalization and from death.”
Fauci said recommending the vaccinated wear masks is “under active consideration” by the government’s leading public health officials. Also, booster shots may be suggested for people with suppressed immune systems who have been vaccinated, Fauci said.
Last week, an Associated Press/NORC Center for Public Affairs Research poll showed most Americans who haven’t been vaccinated against COVID-19 are unlikely to get the shots and doubt they would work against the aggressive delta variant.
Among American adults who have not yet received a vaccine, 35% say they probably will not, and 45% say they definitely will not. Just 3% say they definitely will get the shots, though another 16% say they probably will.
What’s more, 64% of unvaccinated Americans have little to no confidence the shots are effective against variants — including the delta variant that officials say is responsible for 83% of new cases in the U.S. — despite evidence that they offer strong protection. In contrast, 86% of those who have already been vaccinated have at least some confidence that the vaccines will work.
That means “that there will be more preventable cases, more preventable hospitalizations and more preventable deaths,” said Dr. Amesh Adalja, an infectious disease specialist at Johns Hopkins University.
Fauci told CNN’s “State of the Union” that he has taken part in conversations about altering the mask guidelines.
He noted that some local jurisdictions where infection rates are surging, such as Los Angeles County, are already calling on individuals to wear masks in indoor public spaces regardless of vaccination status. Fauci said those local rules are compatible with the CDC recommendation that the vaccinated do not need to wear masks in public.
“This is an issue predominantly among the unvaccinated, which is the reason why we’re out there, practically pleading with the unvaccinated people to go out and get vaccinated,” Fauci said.
Fauci said government experts are reviewing early data as they consider whether to recommend that vaccinated individuals get booster shots. He suggested that some of the most vulnerable, such as organ transplant and cancer patients, are “likely” to be recommended for booster shots.
He also praised Republicans, including Govs. Asa Hutchinson of Arkansas and Ron DeSantis of Florida, and the second-ranking House leader, Rep. Steve Scalise of Louisiana, for encouraging their constituents to get vaccinated. Their states have among the lowest vaccination rates in the country.
“What I would really like to see is more and more of the leaders in those areas that are not vaccinating to get out and speak out and encourage people to get vaccinated,” Fauci said.
In a televised town hall last week, Biden himself expressed frustration over the slowing COVID-19 vaccination rate in the U.S. and pleaded that it’s “gigantically important” for Americans to step up and get inoculated against the virus as it surges once again.
Biden said the public health crisis has turned largely into a plight of the unvaccinated as the spread of the delta variant has led to a surge in infections around the country.
“We have a pandemic for those who haven’t gotten the vaccination — it’s that basic, that simple,” he said.
Tim Darnell of The Atlanta Journal-Constitution contributed to this report.