The WHO says that "according to current evidence," the virus is transmitted through "respiratory droplets and contact routes." By that, the agency means the virus is found in the kind of big droplets of mucus or saliva created through coughing and sneezing.

These droplets can only travel short distances through the air and either land on people or land on surfaces that people later touch. Stopping this kind of transmission is why public health officials urge people to wash hands frequently and not touch the face, because that could bring the virus into contact with the nose or mouth.

The WHO said that this kind of airborne transmission of the new coronavirus might be possible "in specific circumstances and settings in which procedures that generate aerosols are performed," such as when a patient is intubated in a hospital or being disconnected from a ventilator.

Based on that, the agency recommends "airborne precautions" when medical workers do those procedures. Otherwise, the WHO says, healthcare workers caring for COVID-19 patients could use less protective "droplet and contact precautions."