Why the CDC changed its mask advice

The advice from federal health authorities that fully vaccinated people can remove masks in most environments was a surprise to Americans, from state authorities to scientific experts. Even the White House was notified in less than a day by the Centers for Disease Control and Prevention, spokesman Jen Psaki said at a press conference on Friday.

“The CDC, the doctors and medical professionals there, have decided what this guidance is and what the timeline will be, based on their own data,” said Pusaki. “It was not a decision directed or made by the White House.”

For months, federal officials have strongly warned that masks and increased social distance are needed to contain the pandemic. So what has changed?

Introducing a new recommendation on Thursday, CDC Director Dr. Rochelle P. Warrensky cited two recent scientific findings as key factors. The vaccine appears to be effective against all known variants of the coronavirus.

At this point, there is no doubt that the vaccine is powerful. On Friday, the CDC announced that the vaccine produced by Pfizer-BioNTech and Moderna was 94% effective in preventing symptomatic disease in fully vaccinated individuals and 82% in partially vaccinated individuals. We have published the results of another large study showing that it is effective.

Zoe McLaren, a health policy expert at the University of Maryland in Baltimore County, said: Increasing evidence indicates that vaccinated people are very unlikely to catch or infect the virus, she said.

The risk is “definitely not zero, but it’s clear that it’s very low,” she said.

One of the lasting concerns among scientists was that even vaccinated people could carry the virus (perhaps in a short time, without symptoms) and spread it to others. However, CDC studies, including new studies, have consistently found few infections among people vaccinated with Pfizer-BioNTech and Moderna vaccines.

“This study, in addition to many previous studies, was crucial to change the recommendations of the CDC to people who are fully vaccinated against Covid-19,” Dr. Walensky said on Friday. Said in a statement.

Other recent studies have confirmed that people infected after vaccination have too little virus to infect others, said Florian Kramer, a virologist at Mount Sinai School of Medicine.

“It can be difficult to even sequence the viruses because the viruses are so few and only exist for a short period of time,” he said.

Still, most data has been collected for the Pfizer-BioNTech and Moderna vaccines, Dr. Kramer warned. Since the Johnson & Johnson vaccine was later approved, few studies have evaluated its efficacy.

In clinical trials, the Johnson & Johnson vaccine was 72% effective, lower than the Pfizer and Modana vaccines. Efficacy was also measured in terms of moderate to severe illness rather than mild illness.

“I’m confident that this is a very good vaccine and will save many, many, many lives,” said Dr. Kramer. “But J. & J. Vaccines prevent infections and show how much they prevent infections.”

Viral variants have been of particular concern to scientists. Dr. Walensky cited evidence that mRNA vaccines such as Pfizer and Modana are effective against mutants prevalent in the United States, but there is little data on mutants and Johnson & Johnson vaccines. And new variants are constantly emerging.

“I’m not saying this is a big problem right now,” said Dr. Kramer. But before removing the masking requirement, “I might have waited a little longer to see the numbers.”

A CDC spokesman said in a statement on Friday: “All licensed vaccines provide strong protection against serious illness, hospitalization and death. We have accumulated data that licensed vaccines are effective against variants that are endemic in the country. doing. “

People who are completely vaccinated are unlikely to get a serious illness, even if they are infected with the coronavirus. There is an increased risk of infection for those around us, such as unvaccinated children and adults, or those who have been vaccinated unprotected for their condition or treatment.

CDC officials weighed these factors and said they were confident in their scientific assessment. And the new advice has other beneficial effects, rewarding fully vaccinated people by giving them permission to end social isolation, and perhaps encouraging others to choose vaccination. I will.

Dr. Joshua Sharfstein, Vice Dean of Public Health Practices and Community Engagement at the Johns Hopkins University Bloomberg School of Schools, said the new advice: “We are really in the final stages here. This is very for people. I think it’s a good thing. ” health.

“It’s unlikely that there will be a bigger surge in the case,” he added. “But it’s still a question of whether the final stretch lasts for weeks or months.”

According to him and other experts, the difficulty of the new recommendations is not as much of the science that underpins them as their implementation.

The CDC acknowledged immediately on Thursday, so state, city, and county-level leaders still have the authority to request masks from vaccinated people as well. Some states immediately lifted their mask obligations after official announcements, but others said they needed more time to weigh the evidence.

However, in states where masks are not obligatory, the responsibility for checking vaccination status lies with shopkeepers, restaurant workers, school officials, and workplace managers.

Kaitlin Rivers, an epidemiologist at Johns Hopkins University, said:

The number of cases in the country is the lowest since September, and many experts support the removal of mask obligations in many parts of the country. But doing so is more dangerous in places like Michigan, where there are more cases, and for unprotected people, including children under the age of 12 and people with a weak immune system, Dr. Rivers said. Told.

“People who are not vaccinated should continue to wear masks in public indoors and avoid the crowd,” she said.

In Nacogdoches, Texas, Dr. Ahmed Hashim was in a hurry that only 36% of the population was vaccinated and the pace seemed to be stagnant. Still, only one or two in ten people wore masks at local stores.

“I think the CDC may send the wrong message that everything is okay,” said pulmonologist Dr. Hashim. “A 60% or 70% vaccination will make you feel much better.”

Dr. Sharfstein warned that the CDC guidance is intended for fully vaccinated individuals and should be interpreted as such. Nationally, only 36 percent of the population is fully vaccinated.

“What we are seeing now is the perfectly appropriate advice for vaccinated people and the reality that there are still places where the virus is infected and many people who are not vaccinated. It’s a short distance between. “He said.

Individuals can make choices based on their perception of risk, but state and local leaders need to decide what is best for their community based on infection rates. “These are two different things,” said Dr. Sharfstein. “And when they get confused, it’s when people may make bad decisions about policy.”

According to Dr. McLaren, the new guidelines should remind us to step up efforts and investments in health authorities to make vaccines accessible to everyone. Parents of children under the age of 12 should continue to encourage them to wear masks indoors.

The CDC’s new policy also shifts responsibility to immunocompromised people to protect themselves from unmasked and unvaccinated people.

“When we make policies, we need to balance everyone’s needs and desires,” said Dr. McLaren. “We were able to continue masking forever, but there are benefits to returning to a life that looks more normal.”

Health officials need to emphasize that the situation can still change, and the official recommendation for it is, “We need to practice well in response to the changing situation.” I did.