To date, there has been no effective antiviral drug for any known coronavirus.
Forty-two patients are under treatment.
Middle East respiratory syndrome (MERS) can spread quickly in the hospital setting.
The cluster has generated over three dozen cases since the beginning of June.
Officials are investigating the extent of infection among patient contacts, the source of each cluster infection, and any possible links between hospitals.
The total number of confirmed Middle East respiratory syndrome (MERS) cases recorded since September 2012 is 1980, including 699 known deaths.
Saudi Arabia has reported 14 new cases of Middle East respiratory syndrome (MERS) including 10 which are linked to a hospital or hospitals.
This year, Middle East respiratory syndrome (MERS) cases have been moderate in Saudi Arabia.
The Qatar Ministry of Public Health (MOPH) announced that a new Middle East Respiratory Syndrome Corona Virus (MERS-CoV) case has been confirmed, marking the third confirmed MERS-CoV case this year.
An analysis of blood samples taken during South Korea's MERS-CoV outbreak found that disease antibodies were undetectable in four of the six people who had mild infections.