A global havoc unleashed

Coronaviruses have been causing problems

for humanity for a long time.

Several versions are known to trigger

common colds and more recently two types

have set off outbreaks of deadly illnesses:

severe acute respiratory syndrome (Sars)

and Middle East respiratory syndrome (Mers).

But their impact has been mild compared

with the global havoc unleashed by the coronavirus that is causing the Covid-19 pandemic