White cells produce enzymes which help defeat invading disease-causing organisms. Some of these enzymes may also cause tissue damage and one in particular (elastase) may contribute to the invasion of coronavirus into lung tissue. No existing work has examined the relationship between circulating elastase and severity of coronavirus infection. Should a relationship be identified it opens up the possibility of using inhibitors of elastase as treatments for coronavirus infection. These inhibitors already exist as medical treatments, so they need only to repurposed not developed from scratch.