Most people infected with SARS-CoV-2 are able to recover from the disease at home—even if they might experience very stressful disease progressions. Some have no symptoms at all. But about ten percent of those affected become so severely ill that they have to be treated in a hospital. The assumption that a weak immune system is behind a severe progression is short-sighted. Especially with critical progressions, the immune system works under intense pressure, but does not manage to control the virus.