Dr. Killian Hurley:

It is a great question in terms of what puts people at risk of getting fibrosis. Smoking is a risk factor. It does not directly cause fibrosis but, certainly, it is a risk factor. Covid can worsen fibrosis, as Ms O'Donnell said. In our hospital, half the patients who had fibrosis and got Covid in the first wave died in hospital. They did not make it home at all.

Whether Covid causes fibrosis for someone who does not have a pre-existing diagnosis is still unknown. However, we know that when we follow patients a year after they have had Covid and were admitted to hospital, approximately 7% or 8% of them have some sign of scarring or fibrosis on their CT scan. There is a sense that it will put people at risk of fibrosis in the future, but we are unsure about what that number will be. It may take us years to find out that number.