Despite messages from some health officials to the contrary, it’s likely that a mask can help protect a healthy wearer from infection, says Benjamin Cowling, an epidemiologist at the University of Hong Kong. Both surgical masks and the more protective N95 respirators have been shown to prevent various respiratory infections in health care workers; there’s been some debate about which of the two is appropriate for different kinds of respiratory infection patient care. “It doesn’t make sense to imagine that … surgical masks are really important for health care workers but then not useful at all for the general public,” Cowling says.
Some argue that masking everyone would slow the spread of COVID-19—but the evidence is spotty.