The symptoms depend on the type of coronavirus and how serious the infection is. If you have a mild to moderate upper-respiratory infection such as the common cold, your symptoms may include

• Runny nose
• Headache
• Cough
• Sore throat
• Fever
• Not feeling well overall

Some coronaviruses can cause severe symptoms. The infections may turn into bronchitis and pneumonia, which cause symptoms such as

• Fever, which may be quite high if you have pneumonia
• Cough with mucus
• Shortness of breath
• Chest pain or tightness when you breathe and cough

Severe infections are more common in people with heart or lung diseases, people with weakened immune systems, infants, and older adults.

Human coronaviruses usually spread from an infected person to others through

• The air by coughing and sneezing
• Close personal contact, such as touching or shaking hands
• Touching an object or surface with the virus on it, then touching your mouth, nose, or eyes before washing your hands
• Rarely, feces (poop)

There is no vaccine for the new virus.

Chinese authorities have effectively sealed off Wuhan, state media said.

The move was meant to "resolutely contain the momentum of the epidemic spreading" and protect lives, the central city's special command centre against the virus said, according to state broadcaster CCTV.

More than a dozen other Chinese cities also adopted transport restrictions, affecting 56 million people.

Airports around the world have introduced screening measures and some countries are working to evacuate their citizens from Wuhan.