The director of the Centers for Disease Control and Prevention (CDC) on Feb. 8 defended her agency’s promotion of masking after a new study found that protective masks had little effect on the spread of respiratory viruses such as COVID-19.
The Cochrane review analyzed randomized controlled studies, considered the gold standard by U.S. officials and others, but limitations undermined the conclusions, according to CDC Director Dr. Rochelle Walensky.
“One of the limitations of that study, in addition to the fact that it included randomized trials from before COVID-19, is that it stated in the study that people actually had limited update of using masks,” Walensky said during a hearing in Washington. “Of course, randomized trials that look at mask use by people who aren’t wearing them are going to have limited utility.”
The CDC imposed mask mandates on public transportation users, including plane passengers, and on children in Head Start programs as young as 2, contradicting policies from other countries that left younger children maskless, if mandates were imposed at all.
The agency also repeatedly recommended that children, teachers, and others in schools wear masks, as well as people in common settings, such as grocery stores.
Multiple members of Congress pressed Walensky on the Cochrane review, which concluded that the available evidence shows a lack of effect in mask wearing against the spread of influenza or flu-like illnesses.
“While acknowledging the limited data pool, it found no clear sign of a reduction in transmission when using either medical or surgical masks,” Rep. Cathy McMorris Rodgers (R-Wash.) said. “Yet today, CDC still recommends masks in schools for all ages, even though the emotional, mental, physical, and educational toll masking has had on our kids is widely recognized.”
Walensky told Rodgers, “You actually have to wear a mask for it to work.”
The CDC’s mandates and guidance on masks relied on cohort studies, Walensky said.
That included a non-peer-reviewed study that the agency published in its quasi-journal that compared the incidence of COVID-19 case clusters in schools located in districts with mask mandates with schools in districts without forced masking. Only two Arizona counties were studied.
A follow-up study that expanded on the number of districts involved and the time frame found that there was no link between school masking and COVID-19 cases.
The CDC also cites other studies in a scientific brief on the subject, including a randomized controlled trial in Bangladesh that found that masking had little effect on COVID-19 spread and a Chinese study of just 124 households.
Rep. Gary Palmer (R-Ala.) brought up the Cochrane study and said doctors have informed him that masks aren’t effective.
He asked Dr. Lawrence Tabak, acting director of the National Institutes of Health, whether that agency funded any trials examining mask efficacy in schools. Tabak said he wasn’t aware of any.
Walensky defended the lack of research.
“So many studies demonstrated … that masks were working,” during the COVID-19 pandemic, she said, “that I’m not sure anybody would have proposed a clinical trial because in fact there weren’t equipoise.”
Apart from the Bangladesh trial, the two other randomized, clinical trials conducted in other countries provided little data to support masking against COVID-19.
Walensky also said this week that “now is not the moment” to drop mask mandates in schools. Many states have already lifted their mandates and others have recently announced that they’ll rescind their mandates.
During the hearing, Walensky also defended the lockdowns imposed in the United States during the pandemic.
“I agree that we should do everything in our power not to have it happen [again],” she said, referring to school closures and other lockdown policies.
But she recounted how being a clinician in 2020, there was a morgue outside her hospital. When hospitals are overwhelmed and unable to take care of brain tumors and car accident victims, “extraordinary measures are necessary,” Walensky said.
“I do think when there are lockdowns, there’s decreased need for things like motor vehicle accident care,” she said, disagreeing with Rep. Neal Dunn (R-Fla.) on the issue.
When members pointed out that the COVID-19 vaccines don’t stop transmission, undercutting the rationale for vaccine mandates imposed by the Biden administration, Walensky pushed back, claiming that the vaccines prevent severe disease and death. It “doesn’t prevent transmission as well as it did for prior variants, but it does still prevent some,” Walensky said, referring to all vaccines as one type.
The CDC was consulted before the mandates were issued, she confirmed.
“What we have though is a modest prevention, like a 50 percent prevention, of risk of getting infected if you’re up to date on your vaccination, and that’s very important for frontline workers of all types to stay healthy, for children not to infect their grandparents that may be at risk,” said Dr. Robert Califf, commissioner of the Food and Drug Administration.
“If you’re up to date, your risk of dying is reduced by 80 percent.”
Califf was referring to the updated bivalent vaccines, for which there’s no clinical data half a year after the administration authorized them. The U.S. government and outside researchers have said in observational studies that the bivalents provide a subpar boost against infection and a better boost against severe illness.