This isn't necessarily true. The big symptoms of almost any infectious disease are actually the body's response to the disease rather than being caused by the d

This isn't necessarily true. The big symptoms of almost any infectious disease are actually the body's response to the disease rather than being caused by the disease itself. Things like fever, cough, runny nose are usually (very very often) caused by the body to help fight the infection, rather than the infection itself causing them. This means that not having these symptoms isn't necessarily indicative of not having the disease or having less of it. Sometimes the body doesn't respond right.