Globally, the number of people affected by coronavirus disease 2019 (COVID-19) is rapidly increasing. In most (>80%), the illness is relatively mild and can be self-managed out of hospital. However, in about 20% the illness causes respiratory compromise severe enough to require hospital admission 1. Patients with severe and critical disease need full active treatment. This may include oxygen for hypoxaemia and ventilatory support, along with optimal management of complications, e.g. super-imposed bacterial infection, and any underlying co-morbidities, e.g. chronic obstructive pulmonary disease, congestive heart failure. To date, no antiviral agent has shown to be effective in treating the disease 2.