Mers on the other hand, is more tenacious. It first emerged in 2012 in Jordan and about2,500 cases of the disease have been identified so far. It is more deadly than Sars, and has claimed about 850 lives in total.
Like Sars, and unlike Mers, this coronavirus presents symptoms which make it easier to identify.
There is no vaccine for Sarsor Mersthat is both safe and effective in humans.
China is keen to avoid the international anger it provoked in its slow response to Sars. At the time it was accused of covering up the outbreak.