Revising a decision made just two months ago, the Centers for Disease Control and Prevention said on Tuesday that people vaccinated against the coronavirus should resume wearing masks in public indoor spaces in parts of the country where the virus is rising.
CDC officials also recommended universal masking for teachers, staff, students and visitors to schools, regardless of vaccination status and community transmission of the virus. Nevertheless, with additional precautionary measures, schools should return to face-to-face learning in the fall, Dr. Rochelle Walensky, the agency’s director, is expected to say at a press conference on Tuesday.
The recommendations are another ominous twist in the course of the American pandemic, a war-weary admission that the virus is outstripping vaccination efforts. The agency’s move follows rising case numbers in states like Florida and Missouri, as well as increasing reports of breakthrough infections of the more contagious Delta variant in fully immunized people.
White House press secretary Jen Psaki said at a news conference Tuesday that a change in guidelines was critical to “fighting an ever-evolving virus” and that the Biden administration supported the effort.
“Your job is to examine evolving information, data and an evolving historical pandemic and provide guidance to the American public,” Ms. Psaki said.
The vaccines remain remarkably effective against the worst of the consequences of infection with any form of coronavirus, including hospitalization and death. But the new guidelines explicitly apply to both unvaccinated and vaccinated people, a sharp departure from the agency’s position since May that vaccinated people are not required to wear masks in most indoor spaces.
These recommendations, which appeared to signal the end of the pandemic, were based on previous data suggesting that vaccinated people rarely become infected and almost never transmit the virus, making masking unnecessary.
But that was before the arrival of the Delta variant that makes up the majority of infections in the United States today. CDC officials were convinced of new scientific evidence showing that self-vaccinated people can become infected and carry the virus in large quantities, according to three federal officials aware of the discussions.
Some public health experts welcomed the agency’s decision to revise its guidelines. Based on the scientists’ findings on the Delta variant’s ability to cause breakthrough infections, “this is a step in the right direction,” said Dr. Celine Gounder, an infectious disease specialist at Bellevue Hospital Center in New York.
The American Federation of Teachers and the National Education Association, the two leading teacher unions, strongly supported the CDC’s move towards universal masking in schools.
“Masking in schools is an important means of dealing with the changing realities of virus transmission, regardless of vaccination status,” said Randi Weingarten, President of AFT. “It is a necessary precaution until children under the age of 12 can receive a Covid vaccine”. and more Americans over 12 are being vaccinated. “
Whether state and local health authorities are willing to follow the agency’s instructions is far from certain. And there is sure to be resistance from pandemic-weary Americans, especially in regions of the country where vaccination rates are low and concerns about the virus are subdued.
Some jurisdictions, such as Los Angeles County and St. Louis County, Missouri, have already reintroduced mask requirements in response to rising cases. But Arkansas, one of the highest-paying states, has maintained a masking ban even if vaccination rates lag.
As recently as last week, a CDC spokesman said the agency had no plans to change its guidelines unless there was a major change in science. Researchers have started to find disturbing new data.
July 27, 2021, 3:05 p.m. ET
The delta variant is considered to be about twice as contagious as the original version of the virus. Some research now suggests that people infected with the variant carry about a thousand times more viruses than those infected with other variants and may stay infected longer.
CDC officials have been swayed by new research showing that even people who have been vaccinated can carry large amounts of the variant virus down their noses and throats, suggesting they can spread it to others, according to three federal officials familiar with the matter.
Large viral loads, particularly in the nose and throat, can explain reports of breakthrough infections in groups of people who have been vaccinated. For example, an outbreak that began in Provincetown, Massachusetts after the July 4th celebrations has grown to at least 765 cases, according to Steve Katsurinis, chairman of the Provincetown Board of Health.
Of the 469 cases reported in Massachusetts residents, 74 percent were in people who were fully immunized, Katsurinis said.
Smaller clusters of breakthrough infections have been reported after weddings, family gatherings, and dinner parties. Some of those infected had symptoms, but the vast majority were not seriously ill, suggesting that the immunity created by the vaccines is quickly containing the virus.
Vaccines “are not a force field,” said Jennifer Nuzzo, an epidemiologist at the Bloomberg School of Public Health at Johns Hopkins University. Instead, the vaccination trains the immune system to recognize cells that become infected with the virus.
“The term breakthrough infection is probably a bit of a misnomer,” she said. “It’s probably more realistic that we’re talking about breakthrough diseases and how much of them are occurring.”
Understand the state of vaccine mandates in the United States
Dr. Walensky again urged people to get vaccinated on Tuesday, noting that the surge in cases and hospital admissions is greatest in places with low vaccination rates and among those who have not been vaccinated.
She acknowledged that some people vaccinated can become infected with the Delta variant and could be contagious, but claimed that it was a rare occurrence. But the CDC only tracks breakthrough infections that result in hospitalization or death in vaccinated Americans. Officials previously said vaccinated people account for only 3 percent of hospital admissions.
Dr. Gounder and other experts said it was unclear how often vaccinated people passed the virus to others, but it could happen more often than scientists predicted as the original virus spread.
“We have seen an increasing number of breakthrough infections and it seems like most of them occur in places where people are exposed to a lot of Covid,” said Dr. Scott Dryden-Peterson, an infectious disease doctor and epidemiologist in Brigham. & Women’s Hospital in Boston, studying breakthrough infections in Massachusetts.
People who have been vaccinated – especially those with weak immune systems or otherwise at high risk – should consider wearing masks even in areas with low transmission, he said, “Masks can effectively reduce the amount of virus we breathe and keep us from getting sick and so they increase the effectiveness of our vaccine. It’s a good idea almost everywhere in the US. “
Infections have risen rapidly in the United States, averaging more than 56,000 daily cases as of Tuesday, more than four times the number four weeks ago. Hospital admissions have also increased in almost all states, with deaths rising to an average of 275 per day.
“Given what we are seeing, it is imperative now to slow down and contain transmission,” said Dr. Robby Sikka, a doctor who worked with the NBA’s Minnesota Timberwolves, on the new masking guidelines.
“Not everyone with a breakthrough infection is at risk of transmission, but it is important to note that there is a risk of transmission,” he said.
Dr. However, Sikka found that relying on states or localities to establish masking rules would require more testing than is currently done to identify people with mild or asymptomatic infections. “We’re probably not quite ready for that,” he said.
Given that the virus is likely to become endemic and permanently embedded in American life, federal officials need to formulate an even clearer plan for long-term masking, said Dr. Nuzzo.
“The question is, what are the masking off ramps? It’s really important for us to define that, ”she said. “If we want to keep encouraging people to get involved, we have to give them a vision of what we’re working towards.”