It’s Still Hard to Predict Who Will Die From Covid-19

In every epidemic, some die, others become ill and recover, and the luckiest live through infection without symptoms. In today’s pandemic, we are seeing this play out before our eyes. Although the initial epidemiological data show that Covid-19 is more severe in older people, men and those with pre-existing conditions such as heart and lung disease, not everyone with severe disease has these risk factors. And not everyone at risk has the same symptoms, prognosis or outcome.

Why do people manifest such differences? And why is it not possible to predict an individual’s experience? To address this complex question, it is important to first get our terminology right. “Infection” means acquisition of the coronavirus after exposure to it. Infection is not synonymous with exposure — or with disease. Disease is a clinical state associated with cough, fever and other symptoms that ranges from mild to severe. These symptoms arise from damage to tissues and the immune system. Death occurs when there is so much damage that the body cannot maintain blood oxygenation and other necessary functions.