The CDC’s changes to mask guidelines raised questions. Here are 6 answers

Lifting the mask requirement for vaccinated people caught scientists off guard, experts say

woman and child at grocery store not wearing masks with man wearing mask

With the new CDC guidelines, there’s a mix of mask-wearing indoors, which has raised concerns among some health experts.

Jeff Gritchen/MediaNews Group/Orange County Register via Getty Images

The most recent federal guidance on wearing masks offered a glimmer of hope that the pandemic’s end was inching closer, but it has also caused confusion, anger and worry. On May 13, the U.S. Centers for Disease Control and Prevention recommended that fully vaccinated individuals no longer had to wear masks indoors, except in hospitals, on public transit and in other specified places. In that directive, there was incentive for people who hadn’t yet been vaccinated against COVID-19 to go get their shots, but the guidance also left even experts wondering what it meant for individuals and society as a whole.

“Some unfortunately interpreted this guidance as an immediate end to the indoor mask mandates or that the COVID-19 epidemic is essentially over,” Jeffrey Duchin, a public health expert with Public Health – Seattle & King County, told reporters in an Infectious Diseases Society of America news briefing on May 20. That is not the case.

The United States is still recording more than 24,000 cases and about 500 deaths each day from COVID-19. That’s the lowest level in the last 10 months, Gregory Poland, an infectious diseases expert who heads the Mayo Clinic’s Vaccine Research Group in Rochester, Minn., said May 18 in a podcast. But only 38 percent of the total population was fully vaccinated by May 20, according to the CDC.

The recommendation that vaccinated people could forgo masks caught experts off guard, Poland said. “We are only just now getting to a reduced level over the last two weeks of cases, deaths and hospitalizations. By the way, we were at this same level almost one year ago and look at what happened in the intervening year.” With the current levels of vaccination, “this feels a month or two premature in my mind,” he said.

Duchin, Poland and other experts weigh in on the CDC’s recommendation and what it means for the pandemic’s future.

What’s the science the CDC used to make the decision?

There were two key pieces of information that the CDC’s recommendation is based on, says Céline Gounder, an infectious diseases specialist and epidemiologist at New York University Grossman School of Medicine and Bellevue Hospital in New York City. First, real-world studies have shown that mRNA vaccines from Pfizer and Moderna “reduce risk of infection, not just severe disease, hospitalization and death,” says Gounder, who hosts the Epidemic podcast (SN: 3/30/21).

The vaccines are very good, but they aren’t perfect. Some vaccinated people may still catch the coronavirus. But even “if you are one of those individuals who gets a rare breakthrough infection, your risk of transmitting [the virus] onward to other people is exceedingly low,” Gounder says (SN: 5/4/21). That’s the second piece of evidence that swayed CDC’s decision.

“The science is correct,” she says. “What they got wrong is the communications, the behavioral science and the all-of-government approach that needs to be coordinated on the local level.”

What else should the CDC have taken into consideration when making this decision on masks?

Vaccines are less effective at preventing infection with some more transmissible coronavirus variants, including the B.1.351 variant first discovered in South Africa, B.1.617 first reported in India and P.1 first detected in Brazil (SN:1/27/21; SN: 4/14/21). Those variants have been spreading rapidly, even while cases of infections with earlier versions of the virus have declined, says Ali Mokdad, a public health researcher at the University of Washington’s Institute for Health Metrics and Evaluation in Seattle (SN: 5/3/21). While the mRNA vaccines are still about 72 percent to 75 percent effective against the variants, Johnson & Johnson’s vaccine is about 57 percent effective. And vaccines used in other parts of the world are even less effective, potentially leaving more than half of vaccinated people vulnerable to breakthrough infections with the variants.

Masks can help slow the virus’ spread. Simulating spread, Mokdad and colleagues previously predicted that COVID-19 cases, hospitalizations and deaths would decline over the summer, but rebound in the fall and winter (SN: 4/23/21). That rebound will start sooner, probably about mid-August, if people aren’t wearing masks and vaccine hesitancy remains at current levels, Mokdad says.

“Cases will go up and mortality will go up,” he says. It won’t be as severe as last winter’s surge thanks to vaccination, but deaths could peak at more than 2,000 a day. That compares with a peak of 500 deaths a day if mask-wearing is high.

Mokdad is fully vaccinated but continues to wear a mask when around people outside of his household. Some people have charged that vaccinated people who continue to mask up are signaling that vaccines don’t work, but that’s not how Mokdad sees it. “I trust the vaccines,” he says. “I don’t trust the virus. This virus is so opportunistic.”

Knowing human behavior, does changing the masking guidelines make sense? 

The short answer: probably not.

That’s because the CDC’s new guidance assumes that unvaccinated individuals will continue masking, even though people in the United States are not required to show proof of vaccination. This honor system is in contrast to Israel, where vaccinated individuals carry vaccine passports called Green Passes that grant them admission to businesses. 

Public health officials in this country are “hoping that people will be rational actors,” says medical anthropologist Martha Lincoln of San Francisco State University. “I think that is very unfortunate.”

The latest guidance also lacks cultural sensitivity, say Lincoln and others. This decision prioritizes the needs of those who are already vaccinated or have chosen not to vaccinate, while trivializing the risk to vulnerable populations.

Some parents worry that unmasked and unvaccinated individuals could threaten the safety of their young children, for whom the vaccine is not yet available. That may be a valid concern. In elementary schools in Georgia in November and December, cases of COVID-19 were 37 percent lower in schools that required teachers and staff members to wear masks and 39 percent lower in schools that upgraded ventilation, according to a May 21 Morbidity and Mortality Weekly Report. Vaccination rates also continue to remain lower among Black and Hispanic people in the United States due, in part, to limited access to the shots, leaving many at higher risk. People with compromised immune systems, even if vaccinated, are still vulnerable too.

Past epidemics have illustrated the pitfalls of ignoring politics and culture when disease strikes, researchers wrote in the April 2020 Open Anthropology. Namely, absent a culturally sensitive campaign, the disease will likely continue to spread among vulnerable populations resulting in spillover to majority populations. The AIDS epidemic is an example. Two decades after an early strain appeared in Haiti in the 1960s, U.S. officials singled out gay men and heroin users as drivers of the disease. Later studies have shown that structural inequities, such as poor access to medical care in areas most in need and vulnerability to the disease due to pre-existing conditions related to poverty, racism and other factors, were the larger culprit.

Public health officials’ response to COVID-19 has been similar, Lincoln says. “Without understanding the bigger political, informational and cultural dynamics that are factoring into people’s behavior … we’re not going to really move things forward.”

Health officials could have made throwing away that face mask a goal of the vaccination program, Lincoln says. They could have said, for instance, that when a given county has vaccinated, say, 70 percent of the population, the masks could come off. Now, though, reinstituting a mask mandate would be akin to trying to stick toothpaste back into the tube, she says. “You can’t walk this back.”

Mokdad agrees. “In public health messaging, it’s not about what you say. It’s what people hear.”

Vaccines were tested when people were wearing masks. Will this change affect the shots’ effectiveness?

Theoretically there might be more breakthrough infections if people stop wearing masks overall, Jeanne Marrazzo, an infectious disease physician at the University of Alabama at Birmingham said May 20 during an Infectious Diseases Society of America news briefing.

Still, even during the winter surge in the United States there was enormous variability in how people wore masks — with some people wearing masks under their nose, for instance, or not masking up at all. And since all vaccine clinical trial participants were probably wearing masks — correctly or not — vaccinated people should still have the same relative protection from the coronavirus compared with unvaccinated people even when masks aren’t in the equation, Duchin said in the same briefing. 

What’s more, when U.S. vaccine trials were going on, “transmission was rampant. There was so much disease out there that you really had to go out of your way not to get exposed,” Marrazzo said. “In general, I feel confident that the estimates that we got from those trials are going to play out in the real world as things move forward.” That’s assuming no new, highly contagious variants emerge that overwhelm vaccinated populations, she said. 

How do we move forward and continue to protect vulnerable populations?

When the CDC said vaccinated people could go without masks, “it made it more difficult for governors and mayors, companies and universities to have policies that still protect some of their vulnerable populations,” says Julie Swann, a disease modeler and health systems expert at North Carolina State University in Raleigh.

That leaves it up to each individual to decide whether to mask up or not. They have to factor in things like how widely the virus is spreading locally and local vaccination rates, the prevalence of more contagious variants, and the efficacy of the vaccine they got. Johnson & Johnson’s vaccine had lower efficacy in clinical trials than the mRNA vaccines, for instance (SN: 2/27/21).

Robert Wachter, chair of the department of medicine at the University of California, San Francisco tweeted that he would go maskless indoors under three conditions:

  • If everyone in the room has been vaccinated.
  • If any unvaccinated people present are wearing masks.
  • Or if the local COVID-19 rate is so low that it’s unlikely that an unmasked, unvaccinated person might carry the virus.

It’s not an easy calculation, Swann says, noting she’d still wear a mask because her 9-year-old isn’t eligible for a vaccine yet. Still, the pandemic “has made masks more accessible and acceptable to many people in the United States.” That’s important because we could be asked to mask again when cold and flu season comes around or if COVID-19 case counts climb or new variants burst through immune defenses or immunity wanes, she says. “The good thing about masks is that they’re an easy on-off button,” (SN: 5/11/21).

If the decision to wear a mask is left to each individual, what are the social costs?

Unvaccinated people who incorrectly interpret CDC’s guidelines to mean that they don’t need to wear a mask, “will have neither the protection of the mask, nor the protection of the vaccine,” Gounder says. Vaccinated people “might think, ‘Oh, it’s not my problem. They’re just infecting one another.’” That’s not entirely true, because children younger than 12 aren’t eligible for the vaccine yet and there are people who have been vaccinated but remain vulnerable to infection because of weakened immune systems.

COVID-19 spreading among the unvaccinated carries other costs, too, she says. When those people end up in the hospital, if they have private insurance, those costs get passed on to others as higher insurance premiums. If the person is on a government health plan, such as Medicare, Medicaid or Tricare for military members and their families, the costs are passed on to taxpayers. And if the person has no insurance, hospitals pass costs on to other patients. “It’s not like this is cost-free and doesn’t impact the rest of us, too.”

CDC’s word also puts pressure on other countries to follow suit, says Mokdad. But vaccination rates vary widely, some places already have hospital systems overwhelmed by the virus and new coronavirus variants are on the rise (SN: 5/9/21).

“CDC said, ‘It’s over. Go get the vaccine and you can go back to your normal life,’” he says. But just because people are tired of wearing masks doesn’t mean CDC should give them license to dispense with them, he adds. Well-fitting masks can greatly reduce the risk of infection (SN: 2/12/21), and combined with ventilation and filtration masks are a great public health tool, Mokdad says (SN: 5/18/21). It took years to get people to accept seatbelts, condoms and motorcycle helmets, but CDC didn’t give up promoting them. “We didn’t say, ‘Oh, people don’t like condoms so we should tell them to go have sex without a condom.’ So why are we changing our public health approach [on masks]? It’s frustrating.”

CDC’s recommendation is a blanket statement that may not be applicable for everyone, especially people who live in places with high case counts and low vaccination rates, Gounder says. “There needs to be more nuance and detail communicated here.”

Sujata Gupta

Sujata Gupta is the social sciences writer and is based in Burlington, Vt.

Tina Hesman Saey

Tina Hesman Saey is the senior staff writer and reports on molecular biology. She has a Ph.D. in molecular genetics from Washington University in St. Louis and a master’s degree in science journalism from Boston University.

Erin I. Garcia de Jesus is a staff writer at Science News. She holds a Ph.D. in microbiology from the University of Washington and a master’s in science communication from the University of California, Santa Cruz.

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