The Science Behind CDC’s Updated Guide To Masks (Analysis)

Infectologist: Wear face masks for the duration of the 1:51 pandemic

(CNN) – You could almost hear the collective groan of frustration across the country Tuesday as the U.S. Centers for Disease Control and Prevention (CDC) again updated its guide, encouraging more Americans and everyone. schoolchildren and teachers to wear masks to stop the spread of covid-19.

But the healthcare community’s understanding of the coronavirus, its variants, and the efficacy of the vaccine has evolved with the virus itself, and this new guide is based on new information.


The country failed to meet President Joe Biden’s goal of vaccinating 70% of adults with at least one dose by July 4, which he wanted to frame as a United States independence day from Covid-19. Now, as the delta variant spreads, the country is not heading toward independence, but toward wearing a mask.

The new guidance will set up another clash between the federal government’s recommendations and the nine states – many of which where COVID-19 is fierce – that have banned school districts from requiring masks and prevented cities and counties from imposing their own mask use requirements.

What is the new? Children and adults in K-12 schools must wear masks, regardless of vaccination status. Point. Vaccinated Americans should wear masks indoors if they are in areas of high or significant transmission. CDC wants local leaders in high transmission areas to support vaccination and universal mask use. What has not changed? The unvaccinated should always have been wearing masks in public, according to the CDC. Everyone who can should get vaccinated. Why did the guide change?

For two reasons, according to CDC Director Dr. Rochelle Walensky, who briefed reporters on Tuesday.

Those vaccinated can spread the delta variant. Most important of these is that the CDC now believes that vaccinated Americans, while protected from hospitalization and death, can spread the delta variant more than previously thought.

Here’s how Walensky explained this new data:

“The delta variant shows every day its willingness to outsmart us and be an opportunist in areas where we have not shown a reinforced response against it,” he said of the coronavirus strain that now accounts for the majority of EE cases. .UU.

“In the past few days, I have seen new scientific data from recent outbreak investigations showing that the delta variant behaves differently than past strains of the virus that cause covid-19. Information on the delta variant from various states and others countries indicates that, on rare occasions, some vaccinated people infected with the delta variant after vaccination may be contagious and transmit the virus to other people. This new knowledge is concerning and, unfortunately, warrants an update of our recommendations. “

He also hinted at a second reason for the change.

Not enough people were vaccinated. “The greatest spread of cases is occurring in places with low vaccination rates and among unvaccinated people,” he said. “This time and, most importantly, the associated illness, suffering and death could have been prevented with increased vaccination coverage in this country.”

Where is the transmission “high” or “substantial”? You can search for your own county on the CDC website. But those areas comprise more than half the country: nearly 47% are classified as “high” transmission areas by the CDC and more than 17% are classified as “substantial.”

A brief history of the mask guide

Many Americans will be angered by the lack of coherence from the CDC and the nation’s public health policy makers, who have bounced everywhere on masks for the past 16 months of this pandemic:

Warning against wearing masks to avoid running out of scarce supplies (March 2020) Recommend people to cover their faces with cloth covers (April 2020) Recommend that everyone wear a mask in public places (July 2020) Clarify to the vaccinated that it is okay not to wear a mask outdoors (April 2021) Encourage the vaccinated not to wear their masks outdoors or indoors, except in certain circumstances (May 2021) Recommend that only unvaccinated students should wear masks at school (early July 2021)

Some sites are already putting the mask back on. From Los Angeles to St. Louis to Chicago, some places have already re-enacted the guide or mask requirements. The CDC recommendation will expedite those steps.

The US House of Representatives is also putting on the mask again. The House treating physician sent out new guidance Tuesday requiring “well-fitting, medical-grade” masks to be worn in all interior spaces of the House in light of the new CDC guidance.

It is also likely to lead to a change in plans in many school districts preparing for the fall comeback and, in some cases, likely to lead to a political clash.

“There have been so many collisions between politics and science here,” Dr. Sanjay Gupta, CNN’s chief medical correspondent, said Tuesday. “If you look at the science, what the new science says, and this is different from May 13, when the guidance initially changed from the CDC.”

CNN has been tracking how US school districts will treat masks, and even before the new CDC guidance, the nation’s three largest school districts – New York, Los Angeles, and Chicago – had already left. clearly they would require masks in schools.

A separate CNN analysis has found that at least nine states – Arkansas, Arizona, Georgia, Iowa, Oklahoma, South Carolina, Texas, Utah, and Vermont – have enacted laws prohibiting districts from requiring masks in schools. The list of schools banning mask mandates has constantly changed, but so far all are states with Republican governors.

Among the nation’s 12 major districts, all require masks except Florida and Texas, where governors have banned mask mandates in schools.

Overall, at least 14 of the 30 largest US districts are making masks optional for students in school, while another 13 require them. As of Monday, the remaining three districts were undecided.

Texas Democrats have pleaded with Republican Gov. Greg Abbott to overturn the ban on masks in schools within the next year.

In Florida, Republican Governor Ron DeSantis supports vaccination but has vehemently opposed state or local government asking anyone in his state to re-mask.

DeSantis: Florida will not impose the use of masks on children 0:47

“There has been talk of potentially advocating at the federal level imposing mandatory masks on children,” DeSantis said last week. “We’re not doing that in Florida, okay? We need our kids to breathe. We need our kids to be kids.”

Arkansas Governor Asa Hutchinson, whose state is an epicenter of the delta variant, has also rejected the idea of ​​new regulations on masks, in part because the GOP-controlled legislature passed a law rejecting them, but also notes that Children are less likely to become extremely ill.

“We need to vaccinate everyone around that little boy,” Hutchinson, a Republican, told CNN’s Jake Tapper on Sunday. “That’s the cocoon. This is how we protect them.”

The Effect of Combining Covid-19 Vaccines 1:50 A Closer Look at the Timeline of Mask Use

Don’t use it. Leading infectious disease expert Dr. Anthony Fauci said on “60 Minutes” in March 2020 that you’ll save them for healthcare workers: “There’s no reason to walk around with a mask. When you’re in the middle of an outbreak , wearing a mask can make people feel a little better and may even block a drop, but it doesn’t provide the perfect protection that people think of. And often there are unintended consequences – people keep playing with the mask and he keeps touching his face. “

Use it! Then-CDC Director Dr. Robert Redfield in July 2020: “If we all covered our faces for the next four, six, eight, 12 weeks across the country, the transmission of this virus would stop.”

Why evolution? Fauci on July 16, 2020, explaining why the guidance changed: “As the information changes, you have to be flexible enough and humble enough to change the way you think about things. And I think, you know, One of the important things that we are emphasizing right now that really evolved out of a situation that did change is our insistence now on wearing masks. I mean, masks are very important. They protect you from spreading the infection to someone else. “

Vaccinated people may not use them in some cases. Walensky on April 27, 2021: “If you are fully vaccinated and want to attend a small outdoor gathering with vaccinated and unvaccinated people, or dine at an outdoor restaurant with friends from various households, science shows that if you are vaccinated, you can safely do it without a mask, “said the CDC director.

Vaccinated people should remove them. Walensky on May 13, 2021: “If you are fully vaccinated, you can start doing the things you stopped doing because of the pandemic,” he said. “We all long for this moment when we can return to a sense of normalcy.”

Now, in areas of high or substantial transmission, the new guidance is that vaccinated people should put them back on.