President Trump said during a Thursday evening briefing that the White House may soon release nationwide recommendations on wearing face masks.

The apparent shift comes after an expert panel sent a letter to White House Science Adviser Kelvin Droegemeier Wednesday saying the coronavirus SARS-CoV-2 that causes COVID-19 might be spread simply through exhaled breath.

“Currently available research supports the possibility that SARS-CoV-2 could be spread via bioaerosols generated directly by patients’ exhalation,” the letter from Dr. Harvey Fineberg, chair of the Standing Committee on Emerging Infectious Diseases and 21st Century Health Threats, reads.

The letter then continues by citing a few of the most recent studies involving COVID-19. A University of Nebraska Medical Center study found traces of the viral RNA in isolation rooms where the patients were cared for, while another detailed similar findings in samples from hospitals and public spaces in Wuhan, China.

This evidence comes with caveats, a-plenty, however. As Fineberg acknowledges in the letter, the studies cited have not yet been peer reviewed and traces of RNA are not the same as an active virus looking for a host to infect.

“While this research (from the University of Nebraska Medical Center) indicates that viral particles can be spread via bioaerosols, the authors stated that finding infectious virus has proved elusive and experiments are ongoing to determine viral activity in the collected samples.”

In fact, Dr. Mark Rupp, chief of the UNMC Division of Infectious Diseases, said that the virus “doesn’t appear to spread like classic, airborne-spread viruses.”

“We don’t have evidence at this point that COVID-19 would spread in such a fashion, so we need to continue to emphasize the known methods of transmission and the ways to combat such transmission.”

The study Fineberg cited out of Wuhan, also not yet peer-reviewed, reached the troubling conclusion that cleaning floors, donning and removing personal protective equipment and the movements of staff in hospitals might kick up and re-suspend virus-contaminated aerosol.

Fineberg’s letter was in response to a request for information by Droegemeier and concludes by noting that much more research is needed to understand the risk of infection through breathing or talking, before reiterating its initial warning:

“While the current SARS-CoV-2 specific research is limited, the results of available studies are consistent with aerosolization of virus from normal breathing.”

Fineberg also references another preliminary study now under review involving other viruses besides SARS-CoV-2. It found wearing surgical facemasks can help reduce the transmission of infections, but the study focused on masks worn by infected people rather than asymptomatic people.

In short, despite a lack of fully verified evidence at this point, the message being transmitted to the White House is that breathing and talking cannot be ruled out as a possible vector for infection.

Covering your mouth as much as possible in public, either with a mask or the thickest type of cloth possible, certainly can’t hurt.

As Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. recently told CNN: “If we do not have the problem of taking away the masks from the health care workers who need them, I would lean towards it.”