|The new virus emerged in 2012|
By James Gallagher
The new Mers virus, which has killed half of those infected, is "unlikely" to reach the same scale as Sars, ministers in Saudi Arabia say.
Most of the 90 Mers cases reported so far have been in Saudi Arabia.
Mers is from the same group of viruses as the common cold and Sars, which killed 774 people.
However, a detailed analysis of the Saudi cases, published in Lancet Infectious Diseases, did warn of "major gaps" in understanding of the virus.
The Middle East respiratory-syndrome coronavirus (Mers) emerged in 2012 and has infected 90 people worldwide, 45 of them have died.
The global concern is that cases could spread much further, echoing the Sars outbreak.
Cases have been centred on the Middle East - with patients in Jordan, Qatar, Saudi Arabia and the United Arab Emirates. Additional cases in France, Germany, Italy, Tunisia and the UK have all been linked to travel to the Middle East.
Researchers in Saudi Arabia have published details of the 47 cases reported in the country.
They suggest a pattern of mostly older men being infected. Most cases were also in people with other medical problems, more than two-thirds of the reported cases also had diabetes.