Now is the time for everyone to wear masks, the CDC director Dr. Robert Redfield and colleagues wrote in an editorial published Tuesday in the journal JAMA.
While the organization has been slow to warm up to broad mask-wearing recommendations - first advising, but not requiring, healthy members of the general public to cover their faces when out and about April 3 - now, Redfield and colleagues write, masking should be universal because "there is ample evidence" asymptomatic people may be what's keeping the pandemic alive.
"The data is clearly there that masking works," Redfield told JAMA editor Dr. Howard Bauchner during an interview Tuesday that corresponded with the editorial's release. "If we can get everybody to wear a mask right now, I really do think in the next four, six, eight weeks ... we can get this epidemic under control."
In the paper, Redfield, with his CDC colleagues Dr. John Brooks and Dr. Jay Butler, pointed to research demonstrating the effectiveness of masks.
One study of the largest health care system in Massachusetts showed how universal masking of healthcare workers and patients reversed the infection's trajectory among its employees.
They also point to the Missouri hairstylists who were infected with COVID-19 but still did not infect any of their 140 clients, presumably due to the salon's universal masking policy.
A CDC report also released Tuesday details this case, concluding "consistent and correct use of face coverings, when appropriate, is an important tool for minimizing spread of SARS-CoV-2 from presymptomatic, asymptomatic, and symptomatic persons."
Meanwhile, a modeling program out of the University of Washington has projected universal masking could save 45,000 lives by November.
"Mask mandates delay the need for re-imposing closures of businesses and have huge economic benefits," IHME Director Dr. Christopher Murray said in a statement, MarketWatch reported. "Moreover, those who refuse masks are putting their lives, their families, their friends, and their communities at risk."
The JAMA paper also highlights the two key reasons masking works: to protect both the wearer and the people they come in contact with.
While early recommendations focused on masking's benefit to those around you, Redfield and colleagues emphasize the benefit to the wearer as well.
They likened not wearing a mask with choosing to be operated on by a team without any face coverings - an "absurd" option because it's known the clinicians' conversations and breathing would generate microbes that could infect an open wound.
"Face coverings do the same in blocking transmission of SARS-CoV-2," the doctors write.
Proper social distancing and hand-washing are equally important measures, though, when fighting the virus, Redfield told Bauchner.
More people are coming around to mask wearing, with a separate CDC report, also out Tuesday, showing the rates of mask wearing in public increased from 61.9% to 76.4% between April and May.
Redfield told Bauchner he was "heartened" to see President Trump and Vice President Pence setting that example.
But there's still resistance, with the issue remaining politicized - something Redfield and his co-authors hope their editorial will cut through.
"At this critical juncture when COVID-19 is resurging," they write, "broad adoption of cloth face coverings is a civic duty, a small sacrifice reliant on a highly effective low-tech solution that can help turn the tide favorably in national and global efforts against COVID-19."