Amid the global coronavirus outbreak and flu season, there appears to be a shortage of disposable face masks in the D.C. area.

A check of three CVS locations — one in Maryland, one in the District and one in Virginia — found all three to be out of stock, with employees saying that new shipments sell out quickly.

“We’re working with our suppliers to meet customer demand for face masks,” CVS said in a statement. “This demand may cause shortages at some store locations and we’ll resupply those stores as quickly as possible.”

A Walgreens spokesperson said the company has been seeing greater demand for certain products, including face masks.

But the masks may be of limited value, according to Dr. Julie Fischer, an associate professor of microbiology and immunology at Georgetown University.

“Right now we don’t have a lot of data to show that these masks are effective at preventing a person from becoming infected with coronavirus, or with other respiratory viruses,” she said.

“But what we do know is that it is effective for people who are already ill with a respiratory virus, who are coughing and sneezing themselves, to prevent infecting others by wearing these face masks.”

No luck on Amazon, either: Surgical masks, as well as the N95 respirators the Centers for Disease Control recommends for health care professionals treating sick patients, are becoming hard to find online.

On Amazon’s American store front, both are often out of stock, on back order or notably more expensive — sometimes several times their price before the outbreak gained worldwide attention in mid January.