> Cells multiply by themselves all the time. Triggering that effect is how you get cancer. Your heart beats constantly. Triggering that too much (or in the wron

> Cells multiply by themselves all the time. Triggering that effect is how you get cancer. Your heart beats constantly. Triggering that too much (or in the wrong rhythm) is not a good thing. Those are wrong analogies though. Vaccines don't trigger something too much. They trigger the exact same mechanism that will be triggered anyway when you get infected with the actual virus, but in a safe way.