Respiratory physician John Wilson explains the range of Covid-19 impacts, from no symptoms to severe illness featuring pneumonia
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What became known as Covid-19, or the coronavirus, started in late 2019 as a cluster of pneumonia cases with an unknown cause. The cause of the pneumonia was found to be a new virus – severe acute respiratory syndrome coronavirus 2, or Sars-CoV-2. The illness caused by the virus is Covid-19.
Now declared as a pandemic by the World Health Organisation (WHO), the majority of people who contract Covid-19 suffer only mild, cold-like symptoms.