Surprising reversal of COVID mask guidance based on science, CDC says. Here’s the data

Federal health officials announced last week that fully vaccinated Americans can shed their masks during indoor and outdoor activities, large or small, without wearing a mask or physical distancing. Since then, a list of businesses have said they are no longer requiring their vaccinated customers to sport face coverings while shopping.

The announcement — which includes exceptions for select crowded spaces such as buses, trains, planes and doctor’s offices — comes as daily coronavirus cases continue to decline since COVID-19 vaccines rolled out in the U.S., with deaths at their lowest point since last year.

However, the updated guidance has some experts relieved and excited for a quicker return to normal, while others worry the change was rushed, leaving businesses and people with vulnerable immune systems at a disadvantage.

While Centers for Disease Control and Prevention officials are hoping Americans will be “honest with themselves” when it comes to wearing masks and their vaccination status, they also note recent studies show the vaccines are effective in real-world settings, able to protect against more contagious variants and help reduce coronavirus spread among the vaccinated.

“The accumulation of all of those scientific facts, information and evidence brought the CDC to make that decision,” Dr. Anthony Fauci, chief medical advisor to President Biden, said Sunday during CBS’s “Face the Nation.” “You become a dead end to the virus [when you’re vaccinated.] And when there are a lot of dead ends around, the virus is not going to go anywhere.”

“If, in fact, this serves as an incentive for people to get vaccinated, all the better. I hope it does,” Fauci added.

Here’s the science on COVID-19 vaccines the CDC says supports its decision to ease mask guidelines.

COVID-19 vaccines are effective in real-world settings outside of the lab

Initial clinical trials designed to determine if the COVID-19 vaccines were safe and protective occurred in controlled laboratory settings. Now that millions across the globe have been vaccinated, researchers are learning how the shots perform on a more realistic level.

One study of 6,710 health care workers in Israel, over 80% of whom received the Pfizer-BioNTech coronavirus vaccine, showed that the shot “significantly” lowered both symptomatic and asymptomatic (without symptoms) infections after both doses compared to unvaccinated workers.

Only eight fully vaccinated workers came down with symptomatic COVID-19 compared to 38 unvaccinated workers. Meanwhile, asymptomatic infections occurred in 19 fully vaccinated workers and 17 unvaccinated workers — a finding that aligns with previous research that showed breakthrough infections are more likely to be asymptomatic.

Another study deemed the “largest” coronavirus vaccine effectiveness study revealed that the Pfizer and Moderna shots reduced the likelihood of getting sick with COVID-19 by 94% and 82% among fully and partially vaccinated health care workers, respectively.

The research was done among employees from 33 sites in 25 states, and strengthens evidence from initial clinical trials that showed the vaccines were about 95% effective in lab settings.

More research focused on older adults at 24 hospitals across 14 states found the Pfizer and Moderna vaccines were 94% and 64% effective against COVID-19 hospitalization among fully and partially vaccinated people aged 65 and older, respectively.

COVID-19 vaccines protect against coronavirus variants

Shortly after COVID-19 shots rolled out, scientists began warning of more contagious variants that either originated in the U.S. or made their way here, and of their diminishing effects on available vaccines.

Now, emerging evidence suggests there’s not too much to worry about.

One study out of Qatar showed that the Pfizer vaccine was about 90% and 75% effective against the variants discovered in the U.K. — the predominant variant in the U.S. — and South Africa, respectively. Meanwhile, vaccinated people were still about 97% less likely to get severe, critical or fatal COVID-19 if infected with any of the circulating variants.

The research, which was based on over 250,000 fully vaccinated people, also found the vaccine’s effectiveness against the variant from South Africa was about 20% lower than the efficacy seen during clinical trials and real-world settings in Israel and the U.S., but the effect was not enough to overpower overall protection.

COVID-19 vaccines reduce coronavirus spread among the vaccinated

Scientists are still learning about how well COVID-19 vaccines prevent transmission among people who become infected after vaccination, but recently published studies suggest they do an exceptional job.

A study out of Israel found that people who got infected 12 days or more after vaccination had “significantly reduced viral loads” in their bodies compared to unvaccinated people.

The higher the viral load, the more contagious someone can be because they have more virus to shed while coughing, sneezing, talking or even breathing, experts say. Low viral loads among the vaccinated therefore suggests a lower likelihood of spreading the virus and developing severe disease.

“So even though there are breakthrough infections with vaccinated people, almost always the people are asymptomatic and the level of virus is so low it makes it extremely unlikely — not impossible but very, very low likelihood — that they’re going to transmit it,” Fauci told CBS.

Another study published by the CDC found that among 627 vaccinated staff and residents who contracted COVID-19 across 75 nursing homes in Chicago, Illinois, no secondary transmission occurred, meaning no infected vaccinated people spread the virus to others over three months.

Is it really safe to ditch masks if fully vaccinated? Experts split on new CDC guidance

What can happen if kids want a COVID vaccine — but parents refuse? Experts weigh in

Men with obesity may be more likely to die from COVID than women, study finds. Why?

Unvaccinated people may be COVID variant ‘incubators,’ Bill Nye says: ‘It’s not fair’