How many cases have been reported to date?
Only two have been confirmed by laboratory tests. The first patient, who was 60, died in Saudi Arabia after the virus was confirmed in July in a Dutch laboratory.
The second patient, a 49-year-old Qatari, has been flown to London for treatment after travelling recently to Saudi Arabia. He first showed symptoms on 3 September, was admitted to intensive care in Doha, Qatar, on 7 September, and was flown by air ambulance to London on 11 September. The virus was confirmed in this case by the Health Protection Agency's laboratories in Colindale, north London.
Other cases are being investigated. Reports from Saudi Arabia suggest the new virus has also been identified in a patient being treated in Jeddah.
What are coronaviruses?
They were first identified in the 1960s, and were named after the crown-like projections on the surface of the virus. They cause respiratory infections in both humans and animals.
What type is this, and what are the main symptoms?
The new strain has been confirmed in only two cases so there is very limited information on its impact, transmission and severity at this stage. In these cases, patients had a fever, cough, shortness of breath and breathing difficulties. It is not known whether these symptoms are typical or whether the virus may be circulating more widely but causing milder illness.
What is the treatment?
Experts do not have enough information on the virus to make specific treatment recommendations, and can only provide acute respiratory support to those in hospital, the Health Protection Agency says.