Saudi Arabia has announced more cases of Middle East Respiratory Syndrome. The rise in patients - more than 100 in the last two weeks - worries medical authorities in the kingdom and around the world.
Egypt on Saturday announced its first case of MERS. The patient had recently returned from Riyadh.
MERS was first reported in the Middle East in 2012 and is from the same family as the SARS virus, which killed about 800 people worldwide after first appearing in China in 2002. MERS can cause fever and pneumonia, and can lead to death.
The World Health Organisation is monitoring the rise in MERS cases in Saudi Arabia. Riyadh says it has invited five leading vaccine makers to help combat the virus.
So, how much of a threat is MERS?
Presenter: Mike Hanna
Mohammed Al Hajri - manager of Health Protection & Communicable Diseases at the Supreme Council of Health
Dr Daniel Lucey, adjunct professor of Microbiology and Immunology at Georgetown University Medical Center
Dr Ben Neuman, a virologist at the University of Reading who's studied coronaviruses for 17 years